Spring MVC学习 （ RESTful）
- 2019 年 10 月 9 日
- 筆記
是一套规则，不同的系统之间（Vue java Python C# PHP）具体四种不同类型的HTTP 请求分别表示四种基本操作（CRUD）
GET ：查询（R）
POST：添加（C）
PUT：修改（U）
DELETE：删除（D）
Spring MVC 默认支持RESTful 结构
RestHandler.java
package com.xcl.controller; import com.xcl.entity.User; import com.xcl.repository.UserRepository; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.*; import javax.servlet.http.HttpServletResponse; import java.util.Collection; @RestController @RequestMapping("/rest") public class RestHandler { @Autowired private UserRepository userRepository; /** * 查询所有 GET请求 * * @param response * @return */ @GetMapping("/findAll") public Collection<User> findAll(HttpServletResponse response) { response.setContentType("text/json;charset=UTF-8"); return userRepository.findAll(); } /** * 根据ID查询 GET请求 * * @param response * @param id * @return */ @GetMapping("/findById/{id}") public User findAll(HttpServletResponse response, @PathVariable("id") Integer id) { response.setContentType("text/json;charset=UTF-8"); return userRepository.findById(id); } /** * 添加 POST请求 * * @param user */ @PostMapping("/save") public void save(User user) { userRepository.saveOrUpdate(user); } /** * 修改 PUT请求 * * @param user */ @PutMapping("/update") public void update(User user) { userRepository.saveOrUpdate(user); } /** * 删除 DELETE请求 * * @param id */ @DeleteMapping("/delete/{id}") public void deleteById(@PathVariable("id") Integer id) { userRepository.deleteById(id); } }
User.java
package com.xcl.entity; import lombok.AllArgsConstructor; import lombok.Data; import lombok.NoArgsConstructor; @Data @AllArgsConstructor @NoArgsConstructor public class User { private Integer id; private String name; }
UserRepository 接口
package com.xcl.repository; import com.xcl.entity.User; import java.util.Collection; public interface UserRepository { public Collection<User> findAll(); public User findById(Integer id); public void saveOrUpdate(User user); public void deleteById(Integer id); }
UserRepositoryImpl 实现类
package com.xcl.repository.Impl; import com.xcl.entity.User; import com.xcl.repository.UserRepository; import org.springframework.stereotype.Repository; import java.util.Collection; import java.util.HashMap; import java.util.Map; @Repository public class UserRepositoryImpl implements UserRepository { private static Map<Integer,User> map; static { map=new HashMap<>(); map.put(1,new User(1,"张三")); map.put(2,new User(2,"李四")); map.put(3,new User(3,"王五")); map.put(4,new User(4,"小张")); } @Override public Collection<User> findAll() { return map.values(); } @Override public User findById(Integer id) { return map.get(id); } @Override public void saveOrUpdate(User user) { map.put(user.getId(),user); } @Override public void deleteById(Integer id) { map.remove(id); } }
Springmvc.xml 配置
<?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.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd"> <!-- ⾃动扫描 --> <context:component-scan base-package="com.xcl"></context:component-scan> <!-- 视图解析器 --> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <!-- 前缀 --> <property name="prefix" value="/"></property> <!-- 后缀 --> <property name="suffix" value=".jsp"></property> </bean> <!-- JSON 使用--> <mvc:annotation-driven> <!-- 消息转换器 --> <mvc:message-converters> <bean class="com.alibaba.fastjson.support.spring.FastJsonHttpMessageConverter"> </bean> </mvc:message-converters> </mvc:annotation-driven> </beans>
pom.xml 配置
<?xml version="1.0" encoding="UTF-8"?> <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.xcl</groupId> <artifactId>springmvc</artifactId> <version>1.0-SNAPSHOT</version> <packaging>war</packaging> <name>springmvc Maven Webapp</name> <!-- FIXME change it to the project's website --> <url>http://www.example.com</url> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <maven.compiler.source>12</maven.compiler.source> <maven.compiler.target>12</maven.compiler.target> </properties> <dependencies> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.11</version> <scope>test</scope> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>5.1.7.RELEASE</version> </dependency> <dependency> <groupId>javax.servlet</groupId> <artifactId>javax.servlet-api</artifactId> <version>3.0.1</version> </dependency> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <version>1.18.10</version> <scope>provided</scope> </dependency> <!-- https://mvnrepository.com/artifact/com.alibaba/fastjson --> <dependency> <groupId>com.alibaba</groupId> <artifactId>fastjson</artifactId> <version>1.2.62</version> </dependency> </dependencies> <build> <finalName>springmvc</finalName> <pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) --> <plugins> <plugin> <artifactId>maven-clean-plugin</artifactId> <version>3.1.0</version> </plugin> <!-- see http://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_war_packaging --> <plugin> <artifactId>maven-resources-plugin</artifactId> <version>3.0.2</version> </plugin> <plugin> <artifactId>maven-compiler-plugin</artifactId> <version>3.8.0</version> </plugin> <plugin> <artifactId>maven-surefire-plugin</artifactId> <version>2.22.1</version> </plugin> <plugin> <artifactId>maven-war-plugin</artifactId> <version>3.2.2</version> </plugin> <plugin> <artifactId>maven-install-plugin</artifactId> <version>2.5.2</version> </plugin> <plugin> <artifactId>maven-deploy-plugin</artifactId> <version>2.8.2</version> </plugin> </plugins> </pluginManagement> </build> </project>
web.xml 配置
<!DOCTYPE web-app PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN" "http://java.sun.com/dtd/web-app_2_3.dtd" > <web-app> <display-name>Archetype Created Web Application</display-name> <servlet> <servlet-name>springmvc</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <init-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:springmvc.xml</param-value> </init-param> </servlet> <servlet-mapping> <servlet-name>springmvc</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> </web-app>
