This post is in continuation with AngularJS web services tutorial
    Introduction to web services Web services interview questions SOAP web service introduction RESTful web service introduction SOAP web service example in java using eclipse JAX-WS web service eclipse tutorial JAX-WS web service deployment on tomcat Create RESTful web service in java(JAX-RS) using jersey RESTful web service JAXRS json example using jersey RESTful web service JAXRS CRUD example using jersey AngularJS RESTful web service JAXRS CRUD example using $http RESTful Web Services (JAX-RS) @QueryParam Example Spring Restful web services simple example Spring Restful web services json example Spring Restful web services CRUD example
In previous post, we have already seen Restful web services CRUD example. In this post, we will use AngularJS to call rest CRUD APIs. So we are going to create a view and then perform CRUD operations on the basis of button clicks.

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Source code:
click to begin
20KB .zip
Here are steps to create a simple Restful web services(JAXWS)  using jersey which will provide CRUD opertion.

1) Create a dynamic web project using maven in eclipse named "JAXRSJsonCRUDExample"

Maven dependencies 

2) We need to add jersey jars utility in the classpath. 
 
 <dependency>
   <groupId>com.sun.jersey</groupId>
   <artifactId>jersey-servlet</artifactId>
   <version>${jersey.version}</version>
 </dependency>
 <dependency>
   <groupId>com.sun.jersey</groupId>
   <artifactId>jersey-json</artifactId>
   <version>${jersey.version}</version>
 </dependency>
 

Jersey internally uses Jackson for Json Handling, so it will be used to marshal pojo objects to JSON.
Now create pom.xml as follows:
pom.xml
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
 <modelVersion>4.0.0</modelVersion>
 <groupId>com.arpit.java2blog</groupId>
 <artifactId>JAXRSJsonExample</artifactId>
 <packaging>war</packaging>
 <version>0.0.1-SNAPSHOT</version>
 <name>JAXRSJsonExample Maven Webapp</name>
 <url>http://maven.apache.org</url>
   <properties>
        <jersey.version>1.18.3</jersey.version>
    </properties>
 <dependencies>
  <dependency>
   <groupId>junit</groupId>
   <artifactId>junit</artifactId>
   <version>3.8.1</version>
   <scope>test</scope>
  </dependency>
  
  <dependency>
   <groupId>com.sun.jersey</groupId>
   <artifactId>jersey-servlet</artifactId>
   <version>${jersey.version}</version>
  </dependency>
  <dependency>
   <groupId>com.sun.jersey</groupId>
   <artifactId>jersey-json</artifactId>
   <version>${jersey.version}</version>
  </dependency>

  <dependency>
   <groupId>commons-logging</groupId>
   <artifactId>commons-logging</artifactId>
   <version>1.2</version>
  </dependency>
 </dependencies>
 <build>
  <finalName>JAXRSJsonExample</finalName>
  <plugins>
   <plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-compiler-plugin</artifactId>
    <version>3.3</version>
    <configuration>
     <source>1.7</source>
     <target>1.7</target>
    </configuration>
   </plugin>
   <plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-war-plugin</artifactId>
    <configuration>
     <failOnMissingWebXml>false</failOnMissingWebXml>
    </configuration>
   </plugin>
  </plugins>
 </build>

</project>

Application configuration:

3) create web.xml as below:
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xmlns="http://java.sun.com/xml/ns/javaee"
 xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
 version="3.0">
 <display-name>Archetype Created Web Application</display-name>
 <servlet>
  <servlet-name>jersey-serlvet</servlet-name>
  <servlet-class>com.sun.jersey.spi.container.servlet.ServletContainer</servlet-class>
  <init-param>
   <param-name>com.sun.jersey.config.property.packages</param-name>
   <param-value>org.arpit.java2blog.controller</param-value>
  </init-param>
  <init-param>
   <param-name>com.sun.jersey.api.json.POJOMappingFeature</param-name>
   <param-value>true</param-value>
  </init-param>
  
  <load-on-startup>1</load-on-startup>
 </servlet>
 <servlet-mapping>
  <servlet-name>jersey-serlvet</servlet-name>
  <url-pattern>/rest/*</url-pattern>
 </servlet-mapping>
</web-app>

Please change initParam "com.sun.jersey.config.property.package" property to provide correct controller package name if you are not using same package.

Create bean class 

4) Create a bean name "Country.java" in org.arpit.java2blog.bean.
package org.arpit.java2blog.bean;

public class Country{
 
 int id;
 String countryName; 
 long population;
 
 public Country() {
  super();
 }
 public Country(int i, String countryName,long population) {
  super();
  this.id = i;
  this.countryName = countryName;
  this.population=population;
 }
 public int getId() {
  return id;
 }
 public void setId(int id) {
  this.id = id;
 }
 public String getCountryName() {
  return countryName;
 }
 public void setCountryName(String countryName) {
  this.countryName = countryName;
 }
 public long getPopulation() {
  return population;
 }
 public void setPopulation(long population) {
  this.population = population;
 } 
 
}

Create Controller 

5) Create a controller named "CountryController.java" in package org.arpit.java2blog.controller
package org.arpit.java2blog.controller;

import java.util.List;

import javax.ws.rs.DELETE;
import javax.ws.rs.GET;
import javax.ws.rs.POST;
import javax.ws.rs.PUT;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;

import org.arpit.java2blog.bean.Country;
import org.arpit.java2blog.service.CountryService;


@Path("/countries")
public class CountryController {
 
 CountryService countryService=new CountryService();
 
    @GET
    @Produces(MediaType.APPLICATION_JSON)
 public List<Country> getCountries()
 {
  
  List<Country> listOfCountries=countryService.getAllCountries();
  return listOfCountries;
 }

    @GET
    @Path("/{id}")
    @Produces(MediaType.APPLICATION_JSON)
 public Country getCountryById(@PathParam("id") int id)
 {
  return countryService.getCountry(id);
 }
    
    @POST
    @Produces(MediaType.APPLICATION_JSON)
 public Country addCountry(Country country)
 {
  return countryService.addCountry(country);
 }

    @PUT
    @Produces(MediaType.APPLICATION_JSON)
 public Country updateCountry(Country country)
 {
  return countryService.updateCountry(country);
  
 }
 
    @DELETE
    @Path("/{id}")
    @Produces(MediaType.APPLICATION_JSON)
 public void deleteCountry(@PathParam("id") int id)
 {
   countryService.deleteCountry(id);
  
 }
 
}
@Path(/your_path_at_class_level) : Sets the path to base URL + /your_path_at_class_level. The base URL is based on your application name, the servlet and the URL pattern from the web.xml" configuration file.

@Path(/your_path_at_method_level): Sets path to base URL + /your_path_at_class_level+ /your_path_at_method_level

@Produces(MediaType.APPLICATION_JSON[, more-types ]): @Produces defines which MIME type is delivered by a method annotated with @GET. In the example text ("text/json") is produced.

Create Service class

6) Create a class CountryService.java in package org.arpit.java2blog.service
It is just a helper class which should be replaced by database implementation. It is not very well written class, it is just used for demonstration.
package org.arpit.java2blog.service;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

import org.arpit.java2blog.bean.Country;
import org.arpit.java2blog.exception.CountryNotFoundException;

/*
 * It is just a helper class which should be replaced by database implementation.
 * It is not very well written class, it is just used for demonstration.
 */
public class CountryService {

 static HashMap<Integer,Country> countryIdMap=getCountryIdMap();


 public CountryService() {
  super();

  if(countryIdMap==null)
  {
   countryIdMap=new HashMap<Integer,Country>();
   // Creating some object of countries while initializing
   Country indiaCountry=new Country(1, "India",10000);
   Country chinaCountry=new Country(4, "China",20000);
   Country nepalCountry=new Country(3, "Nepal",8000);
   Country bhutanCountry=new Country(2, "Bhutan",7000);


   countryIdMap.put(1,indiaCountry);
   countryIdMap.put(4,chinaCountry);
   countryIdMap.put(3,nepalCountry);
   countryIdMap.put(2,bhutanCountry);
  }
 }

 public List<Country> getAllCountries()
 {
  List<Country> countries = new ArrayList<Country>(countryIdMap.values());
  return countries;
 }

 public Country getCountry(int id)
 {
  Country country= countryIdMap.get(id);

  if(country == null)
  {
   throw new CountryNotFoundException("Country with id "+id+" not found");
  }
  return country;
 }
 public Country addCountry(Country country)
 {
  country.setId(getMaxId()+1);
  countryIdMap.put(country.getId(), country);
  return country;
 }

 public Country updateCountry(Country country)
 {
  if(country.getId()<=0)
   return null;
  countryIdMap.put(country.getId(), country);
  return country;

 }
 public void deleteCountry(int id)
 {
  countryIdMap.remove(id);
 }

 public static HashMap<Integer, Country> getCountryIdMap() {
  return countryIdMap;
 }

 // Utility method to get max id
 public static int getMaxId()
 {   int max=0;
 for (int id:countryIdMap.keySet()) {  
  if(max<=id)
   max=id;

 }  

 return max;


 }
}

AngularJS view 

7) create angularJSCrudExample.html in WebContent folder with following content:
<html>
  <head>  
  
  <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.4.4/angular.js"></script>
    
    <title>AngularJS $http Rest example</title>  
 <script type="text/javascript">
            var app = angular.module("CountryManagement", []);
         
            //Controller Part
            app.controller("CountryController", function($scope, $http) {
         
               
                $scope.countries = [];
                $scope.countryForm = {
                    id : -1,
                    countryName : "",
                    population : ""
                };
         
                //Now load the data from server
                _refreshCountryData();
         
                //HTTP POST/PUT methods for add/edit country 
                // with the help of id, we are going to find out whether it is put or post operation
                
                $scope.submitCountry = function() {
         
                    var method = "";
                    var url = "";
                    if ($scope.countryForm.id == -1) {
                        //Id is absent in form data, it is create new country operation
                        method = "POST";
                        url = 'rest/countries';
                    } else {
                        //Id is present in form data, it is edit country operation
                        method = "PUT";
                        url = 'rest/countries';
                    }
         
                    $http({
                        method : method,
                        url : url,
                        data : angular.toJson($scope.countryForm),
                        headers : {
                            'Content-Type' : 'application/json'
                        }
                    }).then( _success, _error );
                };
         
                //HTTP DELETE- delete country by Id
                $scope.deleteCountry = function(country) {
                    $http({
                        method : 'DELETE',
                        url : 'rest/countries/' + country.id
                    }).then(_success, _error);
                };
 
             // In case of edit, populate form fields and assign form.id with country id
                $scope.editCountry = function(country) {
                  
                    $scope.countryForm.countryName = country.countryName;
                    $scope.countryForm.population = country.population;
                    $scope.countryForm.id = country.id;
                };
         
                /* Private Methods */
                //HTTP GET- get all countries collection
                function _refreshCountryData() {
                    $http({
                        method : 'GET',
                        url : 'http://localhost:8080/AngularjsJAXRSCRUDExample/rest/countries'
                    }).then(function successCallback(response) {
                        $scope.countries = response.data;
                    }, function errorCallback(response) {
                        console.log(response.statusText);
                    });
                }
         
                function _success(response) {
                    _refreshCountryData();
                    _clearFormData()
                }
         
                function _error(response) {
                    console.log(response.statusText);
                }
         
                //Clear the form
                function _clearFormData() {
                    $scope.countryForm.id = -1;
                    $scope.countryForm.countryName = "";
                    $scope.countryForm.population = "";
                
                };
            });
        </script>
        <style>
           
       .blue-button{
     background: #25A6E1;
     filter: progid: DXImageTransform.Microsoft.gradient( startColorstr='#25A6E1',endColorstr='#188BC0',GradientType=0);
     padding:3px 5px;
     color:#fff;
     font-family:'Helvetica Neue',sans-serif;
     font-size:12px;
     border-radius:2px;
     -moz-border-radius:2px;
     -webkit-border-radius:4px;
     border:1px solid #1A87B9
           }     

       .red-button{
    background: #CD5C5C;

    padding:3px 5px;
    color:#fff;
    font-family:'Helvetica Neue',sans-serif;
    font-size:12px;
    border-radius:2px;
    -moz-border-radius:2px;
    -webkit-border-radius:4px;
    border:1px solid #CD5C5C
           }      

       table {
           font-family: "Helvetica Neue", Helvetica, sans-serif;
           width: 50%;
       }

       caption {
           text-align: left;
           color: silver;
           font-weight: bold;
           text-transform: uppercase;
           padding: 5px;
       }

       th {
           background: SteelBlue;
           color: white;
       }


       tbody tr:nth-child(even) {
           background: WhiteSmoke;
       }

       tbody tr td:nth-child(2) {
           text-align:center;
       }

       tbody tr td:nth-child(3),
       tbody tr td:nth-child(4) {
           text-align: center;
           font-family: monospace;
       }

       tfoot {
           background: SeaGreen;
           color: white;
           text-align: right;
       }

       tfoot tr th:last-child {
           font-family: monospace;
       }

       td,th{
            border: 1px solid gray;
            width: 25%;
            text-align: left;
            padding: 5px 10px;
        }
          
            
            
        </style>
    <head>
    <body ng-app="CountryManagement" ng-controller="CountryController">
         <h1>
           AngularJS Restful web services example using $http
        </h1> 
        <form ng-submit="submitCountry()">
            <table>
               
                <tr>
                    <th colspan="2">Add/Edit country</th>
                 </tr>
                <tr>
                    <td>Country</td>
                    <td><input type="text" ng-model="countryForm.countryName" /></td>
                </tr>
                <tr>
                    <td>Population</td>
                    <td><input type="text" ng-model="countryForm.population"  /></td>
                </tr>
                <tr>
                    <td colspan="2"><input type="submit" value="Submit" class="blue-button" /></td>
                </tr>
            </table>
        </form>
        <table>
            <tr>
              
                <th>CountryName</th>
                <th>Population</th>
                <th>Operations</th>
               
            </tr>
 
            <tr ng-repeat="country in countries">
               
    <td> {{ country.countryName }}</td>
    <td >{{ country.population }}</td>  
                
                <td><a ng-click="editCountry(country)" class="blue-button">Edit</a> | <a ng-click="deleteCountry(country)" class="red-button">Delete</a></td>
            </tr>
 
        </table>
 
       
 
       
      
  </body>
</html>

Explanation :

  • We have injected $http as we have done in ajax example through controller constructor.
  • app.controller("CountryController", function($scope, $http) {
             
                   
                    $scope.countries = [];
    ...
    
  • We have defined various methods depending on operations such as editCountry, deleteCountry, submitCountry
  • When you click on submit button on form, it actually calls POST or PUT depending on operation. If you click on edit and submit data then it will be put operation as it will be update on existing resource. If you directly submit data, then it will be POST operation to create new resource,
  • Every time you submit data, it calls refereshCountryData() to refresh country table below.
  • When you call $http, you need to pass method type and URL, it will call it according, You can either put absolute URL or relative URL with respect to context root of web application.
  •  //HTTP GET- get all countries collection
                    function _refreshCountryData() {
                        $http({
                            method : 'GET',
                            url : 'http://localhost:8080/JAXRSJsonCRUDExample/rest/countries'
                        }).then(function successCallback(response) {
                            $scope.countries = response.data;
                        }, function errorCallback(response) {
                            console.log(response.statusText);
                        });
                    }
    


8) It 's time to do maven build.
Right click on project -> Run as -> Maven build

9) Provide goals as clean install (given below) and click on run

Run the application

10) Right click on angularJSCrudExample.html -> run as -> run on server
Select apache tomcat and click on finish

10) You should be able to see below page
URL : "http://localhost:8080/AngularjsJAXRSCRUDExample/angularJSCrudExample.html"


Lets click on delete button corresponding to Nepal and you will see below screen:

Lets add new country France with population 15000


Click on submit and you will see below screen.


Now click on edit button corresponding to India and change population from 10000 to 100000.


Click on submit and you will see below screen:



Lets check Get method for Rest API 

11) Test your get method REST service
URL :"http://localhost:8080/AngularjsJAXRSCRUDExample/rest/countries/".
You will get following output:



As you can see , all changes have been reflected in above get call.

Project structure:


We are done with Restful web services json CRUD example using jersey. If you are still facing any issue, please comment.

AngularJS tutorial:

    AngularJs hello world example AngularJs controller examples AngularJs ng-repeat example AngularJs Built-in filter example AngularJs custom filter example AngularJs ajax example using $http AngularJS RESTful web service JAXRS CRUD example using $http

If you getting 404 error with above steps, you may need to follow below steps:


1) If you are getting this warning into your Tomcat startup console log, then it can cause the issue

WARNING: [SetPropertiesRule]{Server/Service/Engine/Host/Context} Setting property 'source' to 'org.eclipse.jst.j2ee.server: JAXRSJsonCRUDExample' did not find a matching property.

This particular warning basically means that the <Context> element in Tomcat's server.xml contains an unknown attribute source and that Tomcat doesn't know what to do with this attribute and therefore will ignore it.
To resolve this in eclipse,
Remove the project from the server from the Server View. Right click on server -> add and remove

then remove project from server configuration.
Then run the project under the same server. Warning should be removed now
Or if warning still remains then
  • Go to server view
  • Double click on your tomcat server. It will open the server configuration.
  • Under server options check ‘Publish module contents to separate XML files’ checkbox. 
  • Restart your server. This time your page will come without any issues.
2) Try to update Maven project.
Right click on project ->Maven-> update project
then

This should solve you issues.

In this tutorial, we are going to call ajax in angular js using $http service. AngularJS provides multiple services out of the box. $http service can be used to perform http request. It allows you create any http request by just injecting it via controller constructor.
    AngularJs hello world example AngularJs controller examples AngularJs ng-repeat example AngularJs Built-in filter example AngularJs custom filter example AngularJs ajax example using $http AngularJS RESTful web service JAXRS CRUD example using $http
In this example, we are going to read countries.json using ajax request from server and will show data of it in a table.

Ajax request in app.js

var app = angular.module('myApp', []);
 app.controller('java2blogContoller', function($scope,$http) {
      
  var url = "countries.json";
  $http.get(url).success( function(response) {
        $scope.countries = response; 
     });
 });
As you can see here , we are injecting $http in controller function here and assigning response to countries list.

 Lets see complete example: 

 Project structure:

Step 1: Create dynamic web project named "AngularJSAjaxExample" in eclipse.
Step 2: We are going to read counties.json from server. Create countries.json in WebContent folder with below json text.
[
  {
    "id": 1,
    "countryName": "India",
    "population": 10000
  },
  {
    "id": 2,
    "countryName": "Bhutan",
    "population": 7000
  },
  {
    "id": 3,
    "countryName": "Nepal",
    "population": 8000
  },
  {
    "id": 4,
    "countryName": "China",
    "population": 20000
  }
]

Step 3: Create angularJSAjaxExample.html in WebContent folder as below:
<!DOCTYPE html>  
<html>  
<head>  
<meta charset="UTF-8">  
<title>Angular js</title>  
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.5.0/angular.min.js"></script>  
<script src="app.js"></script>  
 <link rel="stylesheet" type="text/css" href="table.css">
</head>  
<body>  
<div ng-app="myApp" ng-controller="java2blogContoller">  
  <table border="1">
    <thead>
  <tr>
     <th>ID</th>
     <th>Country Name</th>
     <th>Population</th>
  </tr>
 </thead>
  <tr ng-repeat="con in countries">
    <td> {{ con.id }}</td>
    <td> {{ con.countryName }}</td>
    <td >{{ con.population }}</td>
   
  </tr>
</table> 
</div>  
</body>  
</html> 
Here we are using ng-repeat tag to iterate counties list and showing it in table.

Step 4 : Create app.js in WebContent folder as below:
var app = angular.module('myApp', []);
 app.controller('java2blogContoller', function($scope,$http) {
      
  var url = "countries.json";

     $http.get(url).success( function(response) {
        $scope.countries = response; 
     });
 });

Step 5: We are going to apply style on this table, so create table.css as below in WebContent folder.
table {
  font-family: "Helvetica Neue", Helvetica, sans-serif
}

caption {
  text-align: left;
  color: silver;
  font-weight: bold;
  text-transform: uppercase;
  padding: 5px;
}

thead {
  background: SteelBlue;
  color: white;
}

th,
td {
  padding: 5px 10px;
}

tbody tr:nth-child(even) {
  background: WhiteSmoke;
}

tbody tr td:nth-child(2) {
  text-align:center;
}

tbody tr td:nth-child(3),
tbody tr td:nth-child(4) {
  text-align: right;
  font-family: monospace;
}

tfoot {
  background: SeaGreen;
  color: white;
  text-align: right;
}

tfoot tr th:last-child {
  font-family: monospace;
}

Step 6: Run the html file on the server. Right click on "angularJSAjaxExample.html" and go to run -> run on server.

You will see below output:

URL: http://localhost:8080/AngularJSAjaxExample/angularJSAjaxExample.html

Source code:

click to begin
20KB .zip


AngularJS tutorial:

    AngularJs hello world example AngularJs controller examples AngularJs ng-repeat example AngularJs Built-in filter example AngularJs custom filter example AngularJs ajax example using $http AngularJS RESTful web service JAXRS CRUD example using $http
ng-repeat is a angular js directive which is often used to display data in tables. It is widely used directive. It works very much similar to java for each loop.

Syntax:

<table>
  <tr ng-repeat="con in countries">
    <td>{{ con.name }}</td>
    <td>{{ con.capital }}</td>
  </tr>
</table>

Here countries is json array defined in app.js.

Lets understand with example .

Copy below text , open notepad , paste it and save it as angularJSExample.html and open it in the browser.


<!DOCTYPE html>  
<html>  
<head>  
<meta charset="UTF-8">  
<title>Angular js</title>  
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.5.0/angular.min.js"></script>  
<script src="app.js"></script>  
  
</head>  
<body>  
<div ng-app="myApp" ng-controller="java2blogContoller">  
  <table border="1">
    <thead>
  <tr>
     <th>Name</th>
     <th>Captial</th>
  </tr>
 </thead>
  <tr ng-repeat="con in countries">
    <td>{{ con.name }}</td>
    <td>{{ con.capital }}</td>
  </tr>
</table>
 </br>  
  
</div>  
</body>  
</html> 

app.js

var app = angular.module('myApp', []);
 app.controller('java2blogContoller', function($scope) {
      
      $scope.countries=
        [
        {"name": "India" , "capital" : "delhi"},
         {"name": "England" , "capital" : "London"},
         {"name": "France" , "capital" : "Paris"},
         {"name": "Japan" , "capital" : "Tokyo"}
               
      ];
         
 });

Output:

When you open html file in browser, you will get following output:

Some other properties: 

There are some properties which is accessible to local scope which we can use in ng-repeat directly.

Variable
Type
Description
$index
number
It carries index of repeated element
$first
boolean
true if repeated element is first element
$middle
boolean
true if repeated element is middle element
$last
boolean
true if repeated element is last element
$even
boolean

It depends on $index.
true if $index is even
$odd
boolean

It depends on $index.
true if $index is odd

Lets change color of odd and even rows of table using $even and $odd.

<!DOCTYPE html>  
<html>  
<head>  
<meta charset="UTF-8">  
<title>Angular js</title>  
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.5.0/angular.min.js"></script>  
<script src="app.js"></script>  
  
</head>  
<body>  
<div ng-app="myApp" ng-controller="java2blogContoller">  
  <table border="1">
    <thead>
  <tr>
     <th>Name</th>
     <th>Captial</th>
  </tr>
 </thead>
  <tr ng-repeat="con in countries">
    <td ng-if="$odd" style="background-color:#f1f1f1"> {{ con.name }}</td>
    <td ng-if="$even" style="background-color:#f1aaaa"> {{ con.name }}</td>
    <td ng-if="$odd" style="background-color:#f1f1f1">{{ con.capital }}</td>
    <td ng-if="$even" style="background-color:#f1aaaa">{{ con.capital }}</td>
  </tr>
</table>
 </br>   
</div>  
</body>  
</html>  

app.js

var app = angular.module('myApp', []);
 app.controller('java2blogContoller', function($scope) {
      
      $scope.countries=
        [
        {"name": "India" , "capital" : "delhi"},
         {"name": "England" , "capital" : "London"},
         {"name": "France" , "capital" : "Paris"},
         {"name": "Japan" , "capital" : "Tokyo"}
               
      ];
         
 });

Output:

When you open html file in browser, you will get following output:

Live demo: 

Angular js on jsbin.com

As you can see, we have used $even to check even row and $odd to check odd row. ng-if is another angular directive which is used for checking if condition. We are going to use ng-repeat in many other examples.

Reference: 
https://docs.angularjs.org/api/ng/directive/ngRepeat

In previous post, we have seen a very simple angularjs hello world example. In this post, we are going to see about controllers.
You can consider controllers as main driver for model view changes. It is a main part of angular js application and It is javascript functions or objects which actually performs ui operation. It controls data of angularjs applications.

What is $scope?

Scope is an object which is glue between model and view. So if you want to pass data from model to view and view to model, it is done through scopes object.

How controllers and scope are related?

Actually controllers passes scope object as constructor parameter and initialise model values and functions. Please don't worry if it sounds very confusing, once we see simple example, you will be able to relate.

Declaration of controller syntax :

You need declare module before creating controller. We will learn about module in our next tutorial.
So we use module's controller method to declare controller.
var app = angular.module('myApp', []);
app.controller('java2blogContoller', function($scope) {
    $scope.java2blogMsg = "Hello from java2blog";
   
});

Simple example:

Copy below text , open notepad , paste it and save it as angularJSControllerExample.html and open it in the browser.

<!DOCTYPE html>  
<html>  
<head>  
<meta charset="UTF-8">  
<title>Angular js</title>  
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.5.0/angular.min.js"></script>  
<script src="app.js"></script>  
  
</head>  
<body>  
<div ng-app="myApp" ng-controller="java2blogContoller">  
  
 </br>  
  {{java2blogMsg}}  !!!  
</div>  
</body>  
</html> 

app.js

var app = angular.module('myApp', []);
app.controller('java2blogContoller', function($scope) {
    $scope.java2blogMsg = "Hello from java2blog";
   
});

Live Demo: 

Angular js controller example

What if you don't want to use $scope?

Yes, you can use controller as option too if you do not want to use $scope variable.
so you need to use
Advantages of using controller as options are:
  • Code becomes more readable.
  • It removes dealing with this scope and bindings.
  • There is no dependency on alias used in view(.html) and javascript

Lets take an example:

Copy below text , open notepad , paste it and save it as angularJSControllerExample.html and open it in the browser.

<!DOCTYPE html>  
<html>  
<head>  
<meta charset="UTF-8">  
<title>Angular js</title>  
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.5.0/angular.min.js"></script>  
<script src="app.js"></script>  
  
</head>  
<body>  
<div ng-app="myApp" ng-controller="java2blogContoller as con">  
  
 </br>  
  {{con.java2blogMsg}}  !!!  
</div>  
</body>  
</html> 

app.js

var app = angular.module('myApp', []);
app.controller('java2blogContoller', function() {
    var cont= this;
    cont.java2blogMsg = "Hello from java2blog with controller as option";
   
});

Live demo: 

Angular js controller as example

AngularJs is an open-source web application framework mainly maintained by Google . It aims to simplify both the development and the testing of such applications by providing a framework for client-side model–view–controller (MVC) and model–view–viewmodel (MVVM) architectures,  It helps you to solve major issues with single web page applications. You need to write very less code to achieve complex functionalities.

AngularJS tutorial:

    AngularJs hello world example AngularJs controller examples AngularJs ng-repeat example AngularJs Built-in filter example AngularJs custom filter example AngularJs ajax example using $http AngularJS RESTful web service JAXRS CRUD example using $http
In this post , we will see how to create angular js example.  I will try to create example as simple as possible.
We need to include angular .js in our pages. This can be done in two ways.
  • go to https://angularjs.org/ and click on download Angular js 1 and copy CDN link
  • You can directly download it from above link and put .js file your folder.

Example :

Copy below text , open notepad , paste it and save it as angularJSExample.html and open it in the browser.

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Angular js</title>
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.5.0/angular.min.js"></script>

</head>
<body>
<div ng-app>
 
 10+40 ={{ 10 + 40 }}
 </br>
 1===2 ? : {{ 1==2 }}
</div>
</body>
</html>


Live demo:

Angular JS example

Explanation:

  • We have included angular js CDN in line number 6
  • If you see closely, we have used ng-app attribute with div element. It is called angular directive (We will learn about this letter). We just need to know that it tells angular about starting point of angular flow. So in this div element , we will have angular js related code.
  • You can understand ng-app as main() method in java
  • {{ }} defines angular expression, so whatever inside it will be evaluated. You can see {{10+40}} becomes 50 here.

What if we do not put ng-app and use angular expression:

  • It won't evaluate the expression as simple as that.
Lets create another div without ng-app and see how it works
Angular js without ng-app

AngularJS did not evaluate expression for second div as it is out of scope for it.

Lets put ng-app at body tag

Angular js ng-app on bidy tag

As you can see, angular js has evaluated expressions for both div tags.

More example:

Lets take another example:
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Angular js</title>
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.5.0/angular.min.js"></script>

</head>
<body>
<div ng-app>
 Name: <input type="text" ng-model="helloWorld" />
 </br>
  Hello {{ helloWorld}}  !!!
</div>
</body>
</html>

Live demo:

Angular js example

Explanation : 

In this example, we have used textbox, so whatever you write in textbox, get reflected with hello.
  • We have used ng-app same as previous example.
  • If you notice, we have also used ng-model this time. It is also angular directive and it binds state of model and view, so whatever you write in text box, it get reflected in {{helloworld}} . You will be able to understand more about in the coming tutorials.

This post is in continuation with web service tutorial (Part -8).
    Introduction to web services Web services interview questions SOAP web service introduction RESTful web service introduction Difference between SOAP and REST web services SOAP web service example in java using eclipse JAX-WS web service eclipse tutorial JAX-WS web service deployment on tomcat Create RESTful web service in java(JAX-RS) using jersey RESTful web service JAXRS json example using jersey RESTful web service JAXRS CRUD example using jersey AngularJS RESTful web service JAXRS CRUD example using $http RESTful Web Services (JAX-RS) @QueryParam Example Spring Rest simple example Spring Rest json example Spring Rest xml example Spring Rest CRUD example
In previous post, we have already seen simple Restful web services(JAXWS)  which returns json as response.In this post, we will extend same example and create Restful web services(JAXWS) using jersey which will provide CRUD(Create, read, update and delete) operation example.

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We will use following annotations for CRUD operation.
Method
Description
Get
It is used to read resource
Post
It is used to create new resource.
It is not idempotent method
Put
It is generally used to update resource.It is idempotent method
Delete
It is used to delete resource

Idempotent means result of multiple successful request will not change state of resource after initial application
For example :
Delete is idempotent method because when you first time use delete, it will delete the resource (initial application) but after that, all other request will have no result because resource is already deleted.

Post is not idempotent method because when you use post to create resource , it will keep creating resource for each new request, so result of multiple successful request will not be same.

Source code:

click to begin
20KB .zip
Here are steps to create a simple Restful web services(JAXWS)  using jersey which will provide CRUD opertion.

1) Create a dynamic web project using maven in eclipse named "JAXRSJsonCRUDExample"

Maven dependencies 

2) We need to add jersey jars utility in the classpath. 
 
 <dependency>
   <groupId>com.sun.jersey</groupId>
   <artifactId>jersey-servlet</artifactId>
   <version>${jersey.version}</version>
 </dependency>
 <dependency>
   <groupId>com.sun.jersey</groupId>
   <artifactId>jersey-json</artifactId>
   <version>${jersey.version}</version>
 </dependency>
 

Jersey internally uses Jackson for Json Handling, so it will be used to marshal pojo objects to JSON.
Now create pom.xml as follows:
pom.xml
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
 <modelVersion>4.0.0</modelVersion>
 <groupId>com.arpit.java2blog</groupId>
 <artifactId>JAXRSJsonExample</artifactId>
 <packaging>war</packaging>
 <version>0.0.1-SNAPSHOT</version>
 <name>JAXRSJsonExample Maven Webapp</name>
 <url>http://maven.apache.org</url>
   <properties>
        <jersey.version>1.18.3</jersey.version>
    </properties>
 <dependencies>
  <dependency>
   <groupId>junit</groupId>
   <artifactId>junit</artifactId>
   <version>3.8.1</version>
   <scope>test</scope>
  </dependency>
  
  <dependency>
   <groupId>com.sun.jersey</groupId>
   <artifactId>jersey-servlet</artifactId>
   <version>${jersey.version}</version>
  </dependency>
  <dependency>
   <groupId>com.sun.jersey</groupId>
   <artifactId>jersey-json</artifactId>
   <version>${jersey.version}</version>
  </dependency>

  <dependency>
   <groupId>commons-logging</groupId>
   <artifactId>commons-logging</artifactId>
   <version>1.2</version>
  </dependency>
 </dependencies>
 <build>
  <finalName>JAXRSJsonExample</finalName>
  <plugins>
   <plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-compiler-plugin</artifactId>
    <version>3.3</version>
    <configuration>
     <source>1.7</source>
     <target>1.7</target>
    </configuration>
   </plugin>
   <plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-war-plugin</artifactId>
    <configuration>
     <failOnMissingWebXml>false</failOnMissingWebXml>
    </configuration>
   </plugin>
  </plugins>
 </build>

</project>

Application configuration:

3) create web.xml as below:
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xmlns="http://java.sun.com/xml/ns/javaee"
 xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
 version="3.0">
 <display-name>Archetype Created Web Application</display-name>
 <servlet>
  <servlet-name>jersey-serlvet</servlet-name>
  <servlet-class>com.sun.jersey.spi.container.servlet.ServletContainer</servlet-class>
  <init-param>
   <param-name>com.sun.jersey.config.property.packages</param-name>
   <param-value>org.arpit.java2blog.controller</param-value>
  </init-param>
  <init-param>
   <param-name>com.sun.jersey.api.json.POJOMappingFeature</param-name>
   <param-value>true</param-value>
  </init-param>
  
  <load-on-startup>1</load-on-startup>
 </servlet>
 <servlet-mapping>
  <servlet-name>jersey-serlvet</servlet-name>
  <url-pattern>/rest/*</url-pattern>
 </servlet-mapping>
</web-app>

Please change initParam "com.sun.jersey.config.property.package" property to provide correct controller package name if you are not using same package.

Create bean class 

4) Create a bean name "Country.java" in org.arpit.java2blog.bean.
package org.arpit.java2blog.bean;

public class Country{
 
 int id;
 String countryName; 
 long population;
 
 public Country() {
  super();
 }
 public Country(int i, String countryName,long population) {
  super();
  this.id = i;
  this.countryName = countryName;
  this.population=population;
 }
 public int getId() {
  return id;
 }
 public void setId(int id) {
  this.id = id;
 }
 public String getCountryName() {
  return countryName;
 }
 public void setCountryName(String countryName) {
  this.countryName = countryName;
 }
 public long getPopulation() {
  return population;
 }
 public void setPopulation(long population) {
  this.population = population;
 } 
 
}

Create Controller 

5) Create a controller named "CountryController.java" in package org.arpit.java2blog.controller
package org.arpit.java2blog.controller;

import java.util.List;

import javax.ws.rs.DELETE;
import javax.ws.rs.GET;
import javax.ws.rs.POST;
import javax.ws.rs.PUT;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;

import org.arpit.java2blog.bean.Country;
import org.arpit.java2blog.service.CountryService;


@Path("/countries")
public class CountryController {
 
 CountryService countryService=new CountryService();
 
    @GET
    @Produces(MediaType.APPLICATION_JSON)
 public List<Country> getCountries()
 {
  
  List<Country> listOfCountries=countryService.getAllCountries();
  return listOfCountries;
 }

    @GET
    @Path("/{id}")
    @Produces(MediaType.APPLICATION_JSON)
 public Country getCountryById(@PathParam("id") int id)
 {
  return countryService.getCountry(id);
 }
    
    @POST
    @Produces(MediaType.APPLICATION_JSON)
 public Country addCountry(Country country)
 {
  return countryService.addCountry(country);
 }

    @PUT
    @Produces(MediaType.APPLICATION_JSON)
 public Country updateCountry(Country country)
 {
  return countryService.updateCountry(country);
  
 }
 
    @DELETE
    @Path("/{id}")
    @Produces(MediaType.APPLICATION_JSON)
 public void deleteCountry(@PathParam("id") int id)
 {
   countryService.deleteCountry(id);
  
 }
 
}
@Path(/your_path_at_class_level) : Sets the path to base URL + /your_path_at_class_level. The base URL is based on your application name, the servlet and the URL pattern from the web.xml" configuration file.

@Path(/your_path_at_method_level): Sets path to base URL + /your_path_at_class_level+ /your_path_at_method_level

@Produces(MediaType.APPLICATION_JSON[, more-types ]): @Produces defines which MIME type is delivered by a method annotated with @GET. In the example text ("text/json") is produced.

Create Service class

6) Create a class CountryService.java in package org.arpit.java2blog.service
It is just a helper class which should be replaced by database implementation. It is not very well written class, it is just used for demonstration.
package org.arpit.java2blog.service;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

import org.arpit.java2blog.bean.Country;

/*
 * It is just a helper class which should be replaced by database implementation.
 * It is not very well written class, it is just used for demonstration.
 */
public class CountryService {

 static HashMap<Integer,Country> countryIdMap=getCountryIdMap();


 public CountryService() {
  super();

  if(countryIdMap==null)
  {
   countryIdMap=new HashMap<Integer,Country>();
  // Creating some objects of Country while initializing
   Country indiaCountry=new Country(1, "India",10000);
   Country chinaCountry=new Country(4, "China",20000);
   Country nepalCountry=new Country(3, "Nepal",8000);
   Country bhutanCountry=new Country(2, "Bhutan",7000);


   countryIdMap.put(1,indiaCountry);
   countryIdMap.put(4,chinaCountry);
   countryIdMap.put(3,nepalCountry);
   countryIdMap.put(2,bhutanCountry);
  }
 }

 public List<Country> getAllCountries()
 {
  List<Country> countries = new ArrayList<Country>(countryIdMap.values());
  return countries;
 }

 public Country getCountry(int id)
 {
  Country country= countryIdMap.get(id);
  return country;
 }
 public Country addCountry(Country country)
 {
  country.setId(countryIdMap.size()+1);
  countryIdMap.put(country.getId(), country);
  return country;
 }
 
 public Country updateCountry(Country country)
 {
  if(country.getId()<=0)
   return null;
  countryIdMap.put(country.getId(), country);
  return country;

 }
 public void deleteCountry(int id)
 {
  countryIdMap.remove(id);
 }

 public static HashMap<Integer, Country> getCountryIdMap() {
  return countryIdMap;
 }
}



7) It 's time to do maven build.
Right click on project -> Run as -> Maven build

8) Provide goals as clean install (given below) and click on run

Run the application

9) Right click on project -> run as -> run on server
Select apache tomcat and click on finish

10) We will test this application in  postman , UI based client for testing restful web applications. It is chrome plugin. Launch postman. If you want java based client, then you can also use how to send get or post request in java.

Get method

11) Test your get method REST service
URL :"http://localhost:8080/JAXRSJsonCRUDExample/rest/countries".
You will get following output:


Post method

12) Post method is used to create new resource. Here we are adding new Country England to country list, so you can see we have used new country json in post body.
URL: "http://localhost:8080/JAXRSJsonCRUDExample/rest/countries".

Use get method to check if above country have been added to country list.


Put Method

13) Put method is used to update resource. Here will update population of nepal using put method.
We will update country json in body of request.
URL : "http://localhost:8080/JAXRSJsonCRUDExample/rest/countries"


Use get method to check population of nepal.


Delete method

14) Delete method is used to delete resource.We will pass id of country which needs to be deleted as PathParam. We are going delete id:4 i.e. china to demonstrate delete method.

URL : "http://localhost:8080/JAXRSJsonCRUDExample/rest/countries/4"


Use get method to check country list.


As you can see, we have deleted country with id 4 i.e. china

Project structure:


We are done with Restful web services json CRUD example using jersey. If you are still facing any issue, please comment.

If you getting 404 error with above steps, you may need to follow below steps:


1) If you are getting this warning into your Tomcat startup console log, then it can cause the issue

WARNING: [SetPropertiesRule]{Server/Service/Engine/Host/Context} Setting property 'source' to 'org.eclipse.jst.j2ee.server: JAXRSJsonCRUDExample' did not find a matching property.

This particular warning basically means that the <Context> element in Tomcat's server.xml contains an unknown attribute source and that Tomcat doesn't know what to do with this attribute and therefore will ignore it.
To resolve this in eclipse,
Remove the project from the server from the Server View. Right click on server -> add and remove

then remove project from server configuration.
Then run the project under the same server. Warning should be removed now
Or if warning still remains then
  • Go to server view
  • Double click on your tomcat server. It will open the server configuration.
  • Under server options check ‘Publish module contents to separate XML files’ checkbox. 
  • Restart your server. This time your page will come without any issues.
2) Try to update Maven project.
Right click on project ->Maven-> update project
then

This should solve you issues.

 

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