spring boot开发教程：使用@RestController 、@Controller注解构造http get、http post请求

叁歲伎倆 2021-09-26 05:18 309阅读 0赞

## spring boot使用 @Controller注解控制构造常见http get 、post请求案例 ##

## 项目结构如下： ##

![这里写图片描述][SouthEast]

## 1、maven依赖pom.xml 配置 ##

具体作用看代码注释。

<?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.yf.springboot</groupId>
    	<artifactId>spring-boot-myfirst</artifactId>
    	<version>0.0.1-SNAPSHOT</version>
    	
    	<parent>
    		<groupId>org.springframework.boot</groupId>
    		<artifactId>spring-boot-starter-parent</artifactId>
    		<version>1.4.1.RELEASE</version>
    	</parent>
    	<properties>
    		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    		<java-version>1.8</java-version>
    	</properties>
    
    	
    	<dependencies>
    
    		<dependency>
    			<groupId>org.springframework.boot</groupId>
    			<artifactId>spring-boot-starter-web</artifactId>
    			
    		</dependency>
    		
    		<dependency>
    			<groupId>com.alibaba</groupId>
    			<artifactId>fastjson</artifactId>
    			<version>1.2.15</version>
    		</dependency>
    		
    		
            <dependency>
            	<groupId>org.springframework.boot</groupId>
            	<artifactId>spring-boot-starter-thymeleaf</artifactId>
            </dependency>
           
             
             
            <dependency>
            	<groupId>org.springframework.boot</groupId>
            	<artifactId>spring-boot-starter-freemarker</artifactId>
            </dependency>
    
    
    	</dependencies>
    
    	
    	<build>
    
    		<plugins>
    
    			<plugin>
    				<groupId>org.springframework.boot</groupId>
    				<artifactId>spring-boot-maven-plugin</artifactId>
    				<configuration>
    				</configuration>
    			</plugin>
    
    			<plugin>
    				<groupId>org.apache.maven.plugins</groupId>
    				<artifactId>maven-compiler-plugin</artifactId>
    				<configuration>
    					<source>1.8</source>
    					<target>1.8</target>
    				</configuration>
    			</plugin>
    
    			
    			<plugin>
    				<groupId>org.springframework.boot</groupId>
    				<artifactId>spring-boot-maven-plugin</artifactId>
    				<dependencies>
    					<dependency>
    						<groupId>org.springframework</groupId>
    						<artifactId>springloaded</artifactId>
    						<version>1.2.3.RELEASE</version>
    					</dependency>
    				</dependencies>
    				<executions>
    					<execution>
    						<goals>
    							<goal>repackage</goal>
    						</goals>
    					</execution>
    
    				</executions>
    				<configuration>
    					<classifier>exec</classifier>
    				</configuration>
    			</plugin>
    
    		</plugins>
    	</build>
    
    
    </project>

采用spring boot主要配置文件application.yml，建议使用装上spring suit插件会有提示，使用IDEA也可以有相应插件支持。  
用yml做配置文件有严格格式和有提示支持，properties文件不太方便。  
没有配置文件，启动的spring boot会默认使用8080端口。

## 2、项目配置文件application.yml ##

server:
      port: 8800
    
    spring:
      thymeleaf:
        prefix: classpath:/templates/
        suffix: .html
        mode: HTML5
        encoding: UTF-8
        content-type: text/html; charset=utf-8
    # 设置缓存为false 为了热部署 host refresh
        cache: false
    # 设置freemarker
      freemarker:
        allow-request-override: false
    # 开发过程建议关闭缓存
        cache: true
        check-template-location: false
        charset: UTF-8
        content-type: text/html; charset=utf-8
        expose-request-attributes: false
        expose-session-attributes: false
        expose-spring-macro-helpers: false
    # prefix: xx
        request-context-attribute: 
    # settings: 
    # 默认后缀就是.ftl
    # suffix: .ftl
    # template-loader-path: classPath:/templates/
    # view-names:

### 3、编写启动主类 ###

注意：main类所在包是其他类的顶级包，这样才能能扫描到controller等注解。  
注意：这里映入了第三方json处理依赖

package com.yf.springboot;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.boot.autoconfigure.web.HttpMessageConverters;
    import org.springframework.context.annotation.Bean;
    import org.springframework.http.converter.HttpMessageConverter;
    
    import com.alibaba.fastjson.serializer.SerializerFeature;
    import com.alibaba.fastjson.support.config.FastJsonConfig;
    import com.alibaba.fastjson.support.spring.FastJsonHttpMessageConverter;
    
    /** * 出现404解决 * 1、地址是否正确 * 2、注解是否对了 * 3、包路径是否正确，能否被扫描到加载到 * 默认启动8080端口 * @Description 这里使用@SpringBootApplication只是一个springBoot应用程序 * @author Administrator * @date 2017-4-21 下午9:08:54 * @version V1.3.1 */
    @SpringBootApplication
    public class Application  
    //extends WebMvcConfigurerAdapter 
    { 
        /** * 添加第三方json工具 * 1、需要再pom.xml加入相关以来 * 2、需要再APP 继承 WeWebMvcConfigurerAdapter 重写configureMessageConverters * 3、或者使用bean注入fastJsonHttpMessageConverters * * * 配置fastjson支持两种方法 * 一：1、启动继承 WebMvcConfigurerAdapter 2、覆盖方法configureMessageConverters * 二：使用bean注入fastJsonHttpMessageConverters * 这里使用@Bean注入 HttpMessageConverters * @Description * @author Administrator * @return */
    	@Bean
    	public HttpMessageConverters fastJsonHttpMessageConverters(){ 
    		//1、定义convert转换消息对象
    		FastJsonHttpMessageConverter fasConverter  = new  FastJsonHttpMessageConverter();
    		//2、添加fastJson的配置信息，比如：是否要格式化返回json数据
    		FastJsonConfig fastJsonConfig = new FastJsonConfig();
    		fastJsonConfig.setSerializerFeatures(SerializerFeature.PrettyFormat);
    		//3、再convert中添加配置信息
    		fasConverter.setFastJsonConfig(fastJsonConfig);
    		HttpMessageConverter<?> converter = fasConverter;
    		return new HttpMessageConverters(converter); 
    	}
        
    	// 1、需要先定义一个conver转换消息对象
    	// 2、添加fastJson配置信息，比如：食肉需要格式化返回json数据
    	// 3、再convert中添加配置信息
    	// 4、讲convert添加到converters中
    	/*@Override public void configureMessageConverters( List<HttpMessageConverter<?>> converters) { super.configureMessageConverters(converters); FastJsonHttpMessageConverter fastConverter = new FastJsonHttpMessageConverter(); FastJsonConfig fastJsonConfig = new FastJsonConfig(); fastJsonConfig.setSerializerFeatures(SerializerFeature.PrettyFormat); fastConverter.setFastJsonConfig(fastJsonConfig); converters.add(fastConverter); }*/
    
    	public static void main ( String[] args )
        { 
        	SpringApplication.run(Application.class, args);  
        }
    
    }

## 4、controller类开发HTTP请求接口 ##

package com.yf.springboot.controller;
    
    import java.util.ArrayList;
    import java.util.Date;
    import java.util.List;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.PathVariable;
    import org.springframework.web.bind.annotation.PostMapping;
    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.yf.springboot.entity.User;
    import com.yf.springboot.entity.User2;
    
    /** * 注解全名： * @Description 使用RestController 相当于@Controller 和 @RequestBody * @author Administrator * @date 2017-4-21 下午9:06:28 * @version V1.3.1 */
    // 相当于 @Controller + @ResponseBody
    // 该注解 方法method 返回类型是String时候则返回string,返回对象时候则讲json_encode 该对象的json字符串
    @RestController
    // @EnableAutoConfiguration
    @RequestMapping("/test")
    public class HelloController { 
    
    	/** * 请求： http://localhost:8800/test/ http方式：get 请求返回contentType: text/plain * 请求responseBody: "Hello page" * * @Description * @author Administrator * @return */
    	@RequestMapping("/")
    	public String index() { 
    		return "Hello page";
    	}
    
    	/** * 请求：http://localhost:8800/test/hello/ * http方式：get 请求 * 返回contentType: text/plain * 请求responseBody: "Hello 123 abc 123 123 !!!" * @Description * @author Administrator * @return */
    	@RequestMapping("/hello")
    	public String hello() { 
    		return "Hello 123 abc 123 123 !!!";
    	}
    
    	/** * 请求：http://localhost:8800/test/hello/testname * 请求返回contentType: * responseBody: "Hello testname!!!" * @Description * @author Administrator * @param myName * @return */
    	@RequestMapping("/hello3/{myName}")
    	public String hello3(@PathVariable String myName) { 
    		return "Hello " + myName + "!!!";
    	}
    
    	/** * 请求：http://localhost:8800/test/hello4?id=123&name=abc * http方式：get * 请求返回contentType: text/plain * 请求responseBody: ""id:123 name:abc"" * @Description * @author Administrator * @param id * @param name * @return */
    	@RequestMapping("/hello4")
    	public String hello3(int id, String name) { 
    		System.out.println("id:" + id + " name:" + name);
    		return "id:" + id + " name:" + name;
    	}
    
    	/** * 请求：http://localhost:8800/test//getDemo/testname * http方式：get * 请求返回contentType: application/json * 请求responseBody: { "createTime": 1495640486000, "id": 123, "name": "good122223" } fastjson支持 * 返回对象则自动解析为json字符串 因为spring boot * 默认使用json解析框架自动返回，返回头是Content-Type:application/json;charset=UTF-8 * @Description * @author Administrator * @param myName * @return {"id":123,"name":"good","createTime":1492782569909} */
    	@RequestMapping("/getDemo/{myName}")
    	User getDemo(@PathVariable String myName) { 
    		User user = new User();
    		user.setId(123);
    		user.setName("good122223");
    		user.setCreateTime(new Date());
    		System.out.println("Hello " + myName + "!!!");
    		return user;
    	}
    
    	/** * 请求：http://localhost:8800/test//getDemo/testname * http方式：get * 请求返回contentType: application/json * 请求responseBody: { "createTime": "2017-05-24 23:43:02", "id": 123, "name": "sss" } * spring boot 默认使用jackjson来解析json 使用fastjson返回json 因为spring boot * 默认使用json解析框架自动返回， 返回头是Content-Type:application/json;charset=UTF-8 * @Description * @author Administrator * @param myName * @return {"createTime":"2017-05-20 13:23:57","id":123,"name":"sss"} */
    	@RequestMapping("/getJson")
    	public User2 getJson() { 
    		User2 user = new User2();
    		user.setId(123);
    		user.setName("sss");
    		user.setCreateTime(new Date());
    		return user;
    	}
    
    	/** * 请求：http://localhost:8800/test//getMapping?id=123&name=abc * http方式：get * 请求返回contentType: application/json * 请求responseBody: { "id": 123, "name": "abc" } * @Description * @param user * @return */
    	// 只有get方式能成功,发送post会报错。@GetMapping = @RequestMapping(method = { RequestMethod.GET }
    	@GetMapping("/getMapping")
    	public User getMapping(User user) { 
    		return user;
    	}
    
    	/** * 请求：http://localhost:8800/test//getMapping2?id=123&name=abc * http方式：get * 请求返回contentType: application/json * 请求responseBody: { "id": 123, "name": "abc" } * 请求boty设置为 application/x-www-form-urlencoded 也可以接受参数 * body : id=123&name=abc * @RequestMapping(value="/getMapping" ) * 等于 @RequestMapping(value="/getMapping" , method={RequestMethod.GET,RequestMethod.POST}) * @Description * @param user * @return */
    	@RequestMapping(value = "/getMapping2", method = {  RequestMethod.GET, RequestMethod.POST })
    	public User getMapping2(User user) { 
    		return user;
    	}
    
    	/** * @RequestBody String 直接获取请求体， 不封装 * 请求：http://localhost:8800/test/get2 * http方式：post * {"createTime":1495640486000,"name":"good122223","id":123} * 请求返回contentType: application/json 请求responseBody: * {"createTime":1495640486000,"name":"good122223","id":123} * @Description * @param user * @return */
    	@RequestMapping("/get2")
    	public User get2(@RequestBody String reqContent, @RequestBody User user) { 
    		// {"name":"abc","id":123}
    		System.out.println("reqContent:" + reqContent);
    		System.out.println(user.toString());
    		return user;
    	}
    
    	/** * 对json数据进行实体类封装 请求：http://localhost:8800/test/user * http方式：post * 请求requestBody: * {"createTime":1495640486000,"name":"good122223","id":123} * 请求返回contentType: application/json * 请求responseBody: {"createTime":1495640486000,"name":"good122223","id":123} * @Description * @param user * @return */
    	// {"id":2,"username":"user2","name":"李四","age":20,"balance":100.00}
    	// 发送格式没application/json
    	@PostMapping("/user")
    	public User postUser(@RequestBody User user) { 
    		System.out.println(user);
    		return user;
    	}
    
    	/** * 请求：http://localhost:8800/test/list-all * http方式：get * 请求返回contentType: * 请求responseBody: [ { "createTime": 1495641815658, "id": 1, "name": * "zhangsan" }, { "createTime": 1495641815658, "id": 1, "name": "zhangsan" * }, { "createTime": 1495641815658, "id": 1, "name": "zhangsan" } ] * * @Description * @param user * @return */
    	@GetMapping("list-all")
    	public List<User> listAll() { 
    		ArrayList<User> list = new ArrayList<User>();
    		User user = new User(1, "zhangsan", new Date());
    		User user2 = new User(1, "zhangsan", new Date());
    		User user3 = new User(1, "zhangsan", new Date());
    		list.add(user);
    		list.add(user2);
    		list.add(user3);
    		return list;
    
    	}
    
    	/** * 会自动使用fastjson进行数据解析 * 请求：http://localhost:8800/test/list-all2 * http方式：get * 请求responseBody: [ { "createTime": "2017-05-25 00:11:11", * "id": 1, "name": "zhangsan" }, { "createTime": "2017-05-25 00:11:11", * "id": 1, "name": "zhangsan" } ] * * @Description * @param user * @return */
    	@GetMapping("list-all2")
    	public List<User2> listAll2() { 
    		ArrayList<User2> list = new ArrayList<User2>();
    		User2 user = new User2(1, "zhangsan", new Date(), "beijing");
    		User2 user2 = new User2(1, "zhangsan", new Date(), "sh");
    		list.add(user);
    		list.add(user2);
    		return list;
    
    	}
    }

## 5、controller开发模板请求接口测试类 ##

package com.yf.springboot.controller;
    
    import java.util.Map;
    
    import org.springframework.stereotype.Controller;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.servlet.ModelAndView;
    
    
    /** * 1、thymeleaf末班文件中 标签是需要闭合的 3.0之前需要不和 * 2、thymeleaf 3.0+ 是可以不强制要求闭合 * 3、支持多个模板 比如thymeleaf 、freemarker可以并存 * @Description 使用RestController 相当于@Controller 和 @RequestBody * @author Administrator * @date 2017-4-21 下午9:06:28 * @version V1.3.1 */
    //@Controller @ResponseBody
    @Controller
    @RequestMapping("/template")
    public class TemplateController { 
    
    	/** * javax.servlet.ServletException: Circular view path [hello]: would dispatch back to the current handler URL [/template/hello] again. Check your ViewResolver setup! (Hint: This may be the result of an unspecified view, due to default view name generation.) * * 摘录答案中的话，When you don’t declare a ViewResolver, spring registers a default InternalResourceViewResolver which creates instances of JstlView for rendering the View. 当你没有声明ViewResolver时，spring会给你注册一个默认的ViewResolver，其是JstlView的实例。它通过RequestDispatcher寻找资源（视图），不过这个资源也可能是Servlet，也就是说，Controller中方法返回字符串（视图名），也可能会解析成Servlet。当你的请求路径与视图名相同时，就会发生死循环。 * @Description * @author Administrator * @return */
    	//报错this may be the result of an unspecified view, due to default view name generation.)] 
    	@RequestMapping("/hello")  
        public String index() {   
            return "hello";  
        }
    	/** * org.thymeleaf.exceptions.TemplateInputException: Error resolving template "hello-1", template might not exist or might not be accessible by any of the configured Template Resolvers * @Description * @author Administrator * @return */
    	@RequestMapping("/hello2")  
        public String index2() {   
            return "hello1";  
        }
    	
    	@RequestMapping("/hello3")  
        public  ModelAndView hello3() {  
    		ModelAndView modelAndView = new ModelAndView("hello1");
            return modelAndView;
    // return "hello1"; 等价于 return modelAndView;
        }
    	
    	@RequestMapping("/hello4")  
        public  String hello4(Map<String,Object> map) {  
    		map.put("name", "Andy");
    		return "hello1";
        }
    	//freemarker 模板
    	@RequestMapping("/helloFtl")  
        public  String hello5() {  
    		return "helloFtl";
        }
    	
    	//freemarker 模板
    		@RequestMapping("/helloFtl2")  
    	    public  String hello6(Map<String,Object> map) {  
    			map.put("name", "Andy");
    			return "helloFtl2";
    	    }
    	
    	
    }

### 对应实体类User和User2仅展示属性 ###

/** * * @Description 测试实体类 * @author Administrator * @date 2017-4-21 下午9:14:27 * @version V1.3.1 */
    public class User { 
    	private int id;
    	private String name;
    	private Date createTime;
    }
    
    
    /** * * @Description fastjson测试实体类 * @author Administrator * @date 2017-4-21 下午9:14:27 * @version V1.3.1 */
    public class User2 { 
    	private int id;
    	private String name;
    	@JSONField(format="yyyy-MM-dd HH:mm:ss")
    	private Date createTime;
    	
    	//不出现
    	@JSONField(serialize=false)
    	private String remark;//备注信息
    }

对应项目模板文件：放在src/main/resources 的templates下 在application.yml中可配置。上面已经给出：

### hello1.html文件内容 ###

<!DOCTYPE html>
    <html>
    <head>
    
    
    
     <title>Insert title here</title>
    </head>
    <body>
    
    	<h1>
    	hello my thymeleaf
    	<br/>
    	this is my first thymeleaf demo
    	</h1>
    	welcome <p th:text="${name}"></p>
    	welcome<span th:text="${name}"></span>
    </body>
    </html>

### helloFtl.ftl文件内容 ###

<!DOCTYPE html>
    <html>
    <head>
    
    
    
     <title>Insert title here</title>
    </head>
    <body>
    	<h1>
    	hello my freemarker
    	<br/>
    	this is my first freemarker demo
    	</h1>
    </body>
    </html>

### helloFtl2 文件内容 ###

<!DOCTYPE html>
    <html>
    <head>
    
    
    
     <title>Insert title here</title>
    </head>
    <body>
    	<h1>
    	hello my freemarker
    	<br/>
    	this is my first freemarker demo
    	</h1>
    	name ${name}
    </body>
    </html>

## 配置热拔插开发 ##

可以配置热拔插开发：建议使用第二种重启不会占用端口具体看pom文件注释，输入参数既可以实现热拔插开发。想要具体了解热部署，请看同分类文章。  
![这里写图片描述][SouthEast 1]

[SouthEast]: /images/20210923/00137933599c456d94d7b6cc79baa11e.png
[SouthEast 1]: /images/20210923/d18a989065184d7aaf352d8cfc470863.png