How To Create Restful Webservice In Java Using Spring

Overview

In this tutorial, we show you how to create a simple Restful web services CRUD example in java using Spring MVC return json. We'll building a spring restful web services annotations using eclipse and tomcat step by step.

Follow the steps mentioned below to develop Restful web services.

Spring 4 MVC RESTFul Web Services JSON CRUD

Watch Tutorial

MySQL database settings

Execute the following MySQL script in order to create a database named jack_rutorial_demo with a table named users .

CREATE DATABASE `jack_rutorial_demo`;  CREATE TABLE  `users` (   `id` int(11) NOT NULL AUTO_INCREMENT,   `firstname` varchar(45) NOT NULL DEFAULT '',   `lastname` varchar(100) NOT NULL DEFAULT '',   `address` varchar(100) NOT NULL DEFAULT '',   PRIMARY KEY (`id`) ) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;

Project Structure

The following screenshot shows final structure of the project.

Project Structure Spring 4 Restful web services crud json example

Create Spring Project in Eclipse

Launch Eclipse IDE.
Go to File-> New-> Others... Select Maven Project under Maven category then click Next.
In New Maven Project wizard, select "Create a simpel project(skip archetype selection)" and click on Next
In next wizard, type " com.jackrutorial " in the "Group ID:" field
Type " SpringRESTFulExample " in the "Artifact Id:" field
Packaging -> War
Click Finish.

Maven Dependencies

We will update pom.xml file to add the required dependencies for the following dependencies.

<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/xsd/maven-4.0.0.xsd">  <modelVersion>4.0.0</modelVersion>  <groupId>com.jackrutorial</groupId>  <artifactId>SpringRESTFulExample</artifactId>  <version>0.0.1-SNAPSHOT</version>  <packaging>war</packaging>   <dependencies>   <dependency>    <groupId>org.springframework</groupId>    <artifactId>spring-webmvc</artifactId>    <version>4.3.0.RELEASE</version>   </dependency>   <dependency>    <groupId>org.springframework</groupId>    <artifactId>spring-tx</artifactId>    <version>4.3.0.RELEASE</version>   </dependency>   <dependency>    <groupId>com.fasterxml.jackson.core</groupId>    <artifactId>jackson-databind</artifactId>    <version>2.7.0</version>   </dependency>   <dependency>    <groupId>javax.servlet</groupId>    <artifactId>javax.servlet-api</artifactId>    <version>3.1.0</version>    <scope>provided</scope>   </dependency>   <dependency>    <groupId>org.springframework</groupId>    <artifactId>spring-jdbc</artifactId>    <version>4.3.0.RELEASE</version>   </dependency>  </dependencies>   <build>   <pluginManagement>    <plugins>     <plugin>      <groupId>org.apache.maven.plugins</groupId>      <artifactId>maven-war-plugin</artifactId>      <version>2.4</version>      <configuration>       <warSourceDirectory>src/main/webapp</warSourceDirectory>       <failOnMissingWebXml>false</failOnMissingWebXml>      </configuration>     </plugin>    </plugins>   </pluginManagement>  </build>  </project>

Spring Application Configuration

To configure Spring web MVC framework, we create class WebConfig , class WebInitializer in src folder with package name com.jackrutorial.config and write the following code in it.

WebConfig.java

package com.jackrutorial.config;  import javax.naming.NamingException; import javax.sql.DataSource;  import org.springframework.beans.factory.annotation.Autowired; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.ComponentScan; import org.springframework.context.annotation.Configuration; import org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate; import org.springframework.jndi.JndiTemplate; import org.springframework.web.servlet.config.annotation.EnableWebMvc; import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;  @Configuration @EnableWebMvc @ComponentScan(basePackages = { "com.jackrutorial" }) public class WebConfig extends WebMvcConfigurerAdapter {    @Autowired  DataSource dataSource;    @Bean  public NamedParameterJdbcTemplate geNamedParameterJdbcTemplate(){   return new NamedParameterJdbcTemplate(dataSource);  }    @Bean  public DataSource getDataSource() throws NamingException{   JndiTemplate jndiTemplate = new JndiTemplate();   DataSource dataSource = (DataSource) jndiTemplate.lookup("java:comp/env/jdbc/springmvc");      return dataSource;  }   }

WebInitializer.java

package com.jackrutorial.config;  import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;  public class WebInitializer extends AbstractAnnotationConfigDispatcherServletInitializer  {   @Override     protected Class[] getRootConfigClasses() {         return new Class[] { WebConfig.class};     }        @Override     protected Class[] getServletConfigClasses() {         return null;     }        @Override     protected String[] getServletMappings() {         return new String[] { "/" };     } }

Creating Model Layer

Create a User class under com.jackrutorial.model and write the following code in it.

User.java

package com.jackrutorial.model;  public class User {  private Integer id;  private String firstname;  private String lastname;  private String address;    public User() {   super();  }    public User(Integer id) {   super();   this.id = id;  }   public Integer getId() {   return id;  }  public void setId(Integer id) {   this.id = id;  }  public String getFirstname() {   return firstname;  }  public void setFirstname(String firstname) {   this.firstname = firstname;  }  public String getLastname() {   return lastname;  }  public void setLastname(String lastname) {   this.lastname = lastname;  }  public String getAddress() {   return address;  }  public void setAddress(String address) {   this.address = address;  } }

Database Access Object Configuration

Create a UserDao interface under com.jackrutorial.dao and write the following code in it.

UserDao.java

package com.jackrutorial.dao;  import java.util.List;  import com.jackrutorial.model.User;  public interface UserDao {    public List            listAllUser();    public void addUser(User user);    public void updateUser(User user);    public void delete(User user);    public User findUserById(User user);   }

Create a UserDaoImpl class implements UserDao Interface under com.jackrutorial.dao package and write the following code in it.

UserDaoImpl.java

package com.jackrutorial.dao;  import java.sql.ResultSet; import java.sql.SQLException; import java.util.ArrayList; import java.util.List;  import org.springframework.beans.factory.annotation.Autowired; import org.springframework.jdbc.core.RowMapper; import org.springframework.jdbc.core.namedparam.MapSqlParameterSource; import org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate; import org.springframework.jdbc.core.namedparam.SqlParameterSource; import org.springframework.stereotype.Repository;  import com.jackrutorial.model.User;  @Repository public class UserDaoImpl implements UserDao {    NamedParameterJdbcTemplate namedParameterJdbcTemplate;    @Autowired  public void setNamedParameterJdbcTemplate(NamedParameterJdbcTemplate namedParameterJdbcTemplate) {   this.namedParameterJdbcTemplate = namedParameterJdbcTemplate;  }   public List            listAllUser() {   List              list = new ArrayList();      String sql = "SELECT id, firstname, lastname, address FROM users";      list = namedParameterJdbcTemplate.query(sql, getSqlParameterByModel(null), new UserMapper());      return list;  }    private SqlParameterSource getSqlParameterByModel(User user){   MapSqlParameterSource parameterSource = new MapSqlParameterSource();   if(user != null){    parameterSource.addValue("id", user.getId());    parameterSource.addValue("firstname", user.getFirstname());    parameterSource.addValue("lastname", user.getLastname());    parameterSource.addValue("address", user.getAddress());   }   return parameterSource;  }    private static final class UserMapper implements RowMapper{    public User mapRow(ResultSet rs, int rowNum) throws SQLException {    User user = new User();    user.setId(rs.getInt("id"));    user.setFirstname(rs.getString("firstname"));    user.setLastname(rs.getString("lastname"));    user.setAddress(rs.getString("address"));        return user;   }     }   public void addUser(User user) {   String sql = "INSERT INTO users(firstname, lastname, address) VALUES(:firstname, :lastname, :address)";      namedParameterJdbcTemplate.update(sql, getSqlParameterByModel(user));  }   public void updateUser(User user) {   String sql = "UPDATE users SET firstname=:firstname, lastname=:lastname, address=:address WHERE id =:id";      namedParameterJdbcTemplate.update(sql, getSqlParameterByModel(user));  }   public void delete(User user) {   String sql = "DELETE FROM users WHERE id=:id";      namedParameterJdbcTemplate.update(sql, getSqlParameterByModel(user));  }   public User findUserById(User user) {   String sql = "SELECT * FROM users WHERE id =:id";      return namedParameterJdbcTemplate.queryForObject(sql, getSqlParameterByModel(user), new UserMapper());  }  }

User Service Layer Configuration

Create a UserService interface under com.jackrutorial.service and write the following code in it.

UserService.java

package com.jackrutorial.service;  import java.util.List;  import com.jackrutorial.model.User;  public interface UserService {  public List            listAllUser();    public void addUser(User user);    public void updateUser(User user);    public void delete(User user);    public User findUserById(User user); }

Create a UserServiceImpl class implements UserService Interface under com.jackrutorial.service package and write the following code in it.

UserServiceImpl.java

package com.jackrutorial.service;  import java.util.List;  import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service;  import com.jackrutorial.dao.UserDao; import com.jackrutorial.model.User;  @Service public class UserServiceImpl implements UserService {    UserDao userDao;    @Autowired  public void setUserDao(UserDao userDao) {   this.userDao = userDao;  }   public List            listAllUser() {   return userDao.listAllUser();  }   public void addUser(User user) {   userDao.addUser(user);  }   public void updateUser(User user) {   userDao.updateUser(user);  }   public void delete(User user) {   userDao.delete(user);  }   public User findUserById(User user) {   return userDao.findUserById(user);  }  }

Rest Controller Annotation Configuration

Create a UserController class under com.jackrutorial.controller package and write the following code in it.

UserController.java

package com.jackrutorial.controller;  import java.util.List;  import org.springframework.beans.factory.annotation.Autowired; import org.springframework.http.HttpHeaders; import org.springframework.http.HttpStatus; import org.springframework.http.ResponseEntity; import org.springframework.web.bind.annotation.PathVariable; import org.springframework.web.bind.annotation.RequestBody; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import org.springframework.web.bind.annotation.RestController; import com.jackrutorial.model.User;  import com.jackrutorial.service.UserService;  @RestController public class UserController {    @Autowired  UserService userService;    @RequestMapping(value="/user/", method = RequestMethod.GET, headers="Accept=application/json")  public ResponseEntity<List<User>> listAllUser(){   List<User> list = userService.listAllUser();      if(list.size() == 0){    return new ResponseEntity<List<User>>(HttpStatus.NO_CONTENT);   }      return new ResponseEntity<List<User>>(list, HttpStatus.OK);  }    @RequestMapping(value="/add/", method = RequestMethod.POST, headers="Accept=application/json")  public ResponseEntity<Void> add(@RequestBody User user){   userService.addUser(user);      HttpHeaders headers = new HttpHeaders();   return new ResponseEntity<Void>(headers, HttpStatus.CREATED);  }    @RequestMapping(value="/update/{id}", method = RequestMethod.PUT, headers="Accept=application/json")  public ResponseEntity<Void> update(@PathVariable("id") int id, @RequestBody User user){   user.setId(id);   userService.updateUser(user);      HttpHeaders headers = new HttpHeaders();   return new ResponseEntity<Void>(headers, HttpStatus.OK);  }    @RequestMapping(value="/delete/{id}", method = RequestMethod.DELETE, headers="Accept=application/json")  public ResponseEntity<Void> delete(@PathVariable("id") int id, @RequestBody User user){   user.setId(id);   userService.delete(user);      HttpHeaders headers = new HttpHeaders();   return new ResponseEntity<Void>(headers, HttpStatus.NO_CONTENT);  } }

Building Spring Restful web services

Right click this project
Select Run As -> Maven clean
Right click this project
Select Run As -> Maven install

How to deploy Spring Restful Web Service in Tomcat

Watch video add Apache Tomcat Server in Eclipse.

Enter the following to the Host node in the TOMCAT_HOME/conf/server.xml .

<Context docBase="<Project Folder Location>\SpringRESTFulExample\target\SpringRESTFulExample-0.0.1-SNAPSHOT\" path="/SpringRESTFulExample" reloadable="true" >
              <Resource
                    name="jdbc/springmvc"
                    auth="Container"
                    type="javax.sql.DataSource"
                    username="root"
                     password="root"
                     driverClassName="com.mysql.jdbc.Driver"
                     url="jdbc:mysql://localhost:3306/jack_rutorial_demo"
                     maxActive="5"
                     maxIdle="3"
                      />
</Context>

Start Apache Tomcat from Eclipse Oxygen java .

How to test Spring MVC Restful web services using postman

Add User API

Request Method: POST
URL: http://localhost:8080/SpringRESTFulExample/add/
Body: Type application/json

{  "firstname" : "Jack",  "lastname" : "Rutorial",  "address" : "http://www.jackrutorial.com" }

Add User postman - Spring 4 Restful Web Services CRUD JSON Example

GET User API

Request Method: GET
URL: http://localhost:8080/SpringRESTFulExample/user/

List User postman - Spring 4 Restful Web Services CRUD JSON Example

Update User API

Request Method: PUT
URL: http://localhost:8080/SpringRESTFulExample/update/1
Body: Type application/json

{  "firstname" : "Jack Updated",  "lastname" : "Rutorial Updated",  "address" : "http://www.jackrutorial.com Updated" }

Update User postman - Spring 4 Restful Web Services CRUD JSON Example

Delete User API

Request Method: DELETE
URL: http://localhost:8080/SpringRESTFulExample/delete/1
Body: Type application/json

{}

Delete User postman - Spring 4 Restful Web Services CRUD JSON Example

Required Libraries

mysql-connector-java-5.1.45-bin.jar
Apache tomcat 7
Postman