SpringMVC RESTful 实践demo

1.REST是一种web service架构风格，而不是技术，如果一个架构符合REST原则，就称它为RESTful架构。

RESTful风格的架构都是对资源的操作，所有资源应该是名词而不是动词。

创建一个资源 : POST

检索一个资源 : GET

更新一个资源: PUT

删除一个资源: DELETE

下面是一个实例演示怎样使用HTTP的请求来操作资源。

GET: /students 将返回所有student的信息

GET: /students/101 将返回id为101的学生信息

POST： /students/101 将新建id为101的学生信息

PUT: /students/101 将更新id为101的学生信息

DELETE: /students/101 将删除id为101的学生信息

2.pom.xml文件如下：

<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.example</groupId>
<artifactId>SpringMVC_RESTful</artifactId>
<packaging>war</packaging>
<version>0.0.1-SNAPSHOT</version>
<name>SpringMVC_RESTful Maven Webapp</name>
<url>http://maven.apache.org</url>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>

4000
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>4.3.1.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aop</artifactId>
<version>4.3.1.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>4.3.1.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>4.3.1.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-tx</artifactId>
<version>4.1.6.RELEASE</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>3.1.0</version>
</dependency>
<dependency>
<groupId>commons-logging</groupId>
<artifactId>commons-logging</artifactId>
<version>1.1</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.5.0</version>
</dependency>
</dependencies>
<build>
<finalName>SpringMVC_RESTful</finalName>
</build>
</project>

2.web.xml文件如下：

<?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" id="WebApp_ID" version="3.0">
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>

<servlet>
<servlet-name>springmvc</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>/WEB-INF/springmvc-servlet.xml</param-value>
</init-param>
<!-- <load-on-startup>1</load-on-startup> -->
</servlet>

<servlet-mapping>
<servlet-name>springmvc</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
</web-app>

3.springmvc-servlet.xml文件如下：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.1.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.1.xsd"> 
<!-- 启用spring mvc 注解 -->
<context:annotation-config />
<!-- scan the package and the sub package -->
<context:component-scan base-package="com.example" />

<!-- if you use annotation you must configure following setting -->
<mvc:annotation-driven />
<!-- 完成请求和注解POJO的映射 -->
<bean
class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter" />
<!-- configure the InternalResourceViewResolver 一种试图解析器 -->
<bean
class="org.springframework.web.servlet.view.InternalResourceViewResolver"
id="internalResourceViewResolver">

<property name="prefix" value="/WEB-INF/"/>

<property name="suffix" value=".jsp" />
</bean>
</beans>

4.实体类

public class Student {
private long id;
private String name;
private String sex;

public Student() {
}

public Student(String name, String sex) {
super();
this.name = name;
this.sex = sex;
}

public Student(long id, String name, String sex) {
super();
this.id = id;
this.name = name;
this.sex = sex;
}

public long getId() {
return id;
}

public void setId(long id) {
this.id = id;
}

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}

public String getSex() {
return sex;
}

public void setSex(String sex) {
this.sex = sex;
}
}

5.DAO

package com.example.dao;

import java.util.List;

import com.example.model.Student;

public interface StudentDao {
public Student addStudent(Student student);
public long deleteStudent(Long id);
public Student queryOneStudent(Long id);
public Student changeStudent(Student student);
public List<Student> getStudentList();
}

6.Studen
10258
tDaoImpl

package com.example.dao.impl;

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

import org.springframework.stereotype.Repository;

import com.example.dao.StudentDao;
import com.example.model.Student;

@Repository("studentDao")
public class StudentDaoImpl implements StudentDao {

private static List<Student> students;
{
students = new ArrayList<Student>();
students.add(new Student(101, "Mike", "male"));
students.add(new Student(102, "Huang", "male"));
students.add(new Student(103, "Mao", "female"));
}

public Student addStudent(Student student) {
//student.setId(System.currentTimeMillis());
students.add(student);
return student;
}

public long deleteStudent(Long id) {
for (Student student : students) {
if (student.getId() == id){
students.remove(student);
return id;
}
}
return id;
}

public Student queryOneStudent(Long id) {
for (Student student : students) {
if (student.getId() == id){
return student;
}
}
return null;
}

public Student changeStudent(Student student) {
for (Student s : students) {
if (s.getId() == student.getId()){
return student;
}
}
return null;
}

public List<Student> getStudentList() {
return students;
}

}

7.控制层，这里将对应HTTP请求的方式，在RequestMethod中选择方式，用@PathVariable注解来标记id。

package com.example.controller;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.servlet.ModelAndView;

import com.example.dao.StudentDao;
import com.example.model.Student;

@RestController()
public class StudentController {

@Autowired
private StudentDao studentDao;

@RequestMapping(value = "/students", method = RequestMethod.GET)
@ResponseBody
public List<Student> getStudentList() {
List<Student> students = studentDao.getStudentList();
return students;
}

@RequestMapping(value = "/students/{id}", method = RequestMethod.GET)

public ResponseEntity<Student>  queryOneStudent(@PathVariable("id") long id) {
Student student = studentDao.queryOneStudent(id);
return new ResponseEntity<Student>(student,HttpStatus.OK);
}

@RequestMapping(value = "/students/{id}", method = RequestMethod.DELETE)
public ResponseEntity<Long> deleteStudent(@PathVariable("id") long id) {
long showId = studentDao.deleteStudent(id);
return new ResponseEntity<Long>(showId,HttpStatus.OK);
}

@RequestMapping(value = "/students/{id}", method = RequestMethod.POST)
public ResponseEntity<Student> addStudent(@PathVariable("id") long id) {
Student student = new Student(id,"rex", "male");
student = studentDao.addStudent(student);
return new ResponseEntity<Student>(student,HttpStatus.OK);
}

@RequestMapping(value = "/students/{id}", method = RequestMethod.PUT)
public ResponseEntity<Student> changeStudent(@PathVariable("id") long id) {
Student student = new Student(id,"leona", "female");
student = studentDao.changeStudent(student);
return new ResponseEntity<Student>(student,HttpStatus.OK);
}

}

8.使用google浏览器的扩展应用 POSTMAN 来进行测试，可以很方便的选择请求方式。