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  • SpringBoot2.x请求注解简单介绍(4)

    1.新建项目,项目中实战讲解注解作用

    2.pom.xml依赖配置

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.1.RELEASE</version>
    </parent>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
    </dependencies>

    3.Application.java 程序入口配置

    package xiaobing.demo;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    
    @SpringBootApplication
    public class Application {
    
        public static void main(String[] args) {
            SpringApplication.run(Application.class,args);
        }
    }

    4.demo映射

    package xiaobing.demo.controller;
    
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    @RestController
    public class Example {
    
        @RequestMapping("/")
        String home() {
            return "Hello World!";
        }
    }

    5.注解详解

    5.1 @SpringBootApplication = @Configuration+@EnableAutoConfiguration+@ComponentScan

     

    @SpringBootApplication
    public class Application {
    
        public static void main(String[] args) {
            SpringApplication.run(Application.class,args);
        }
    }
    //等同于:
    @SpringBootConfiguration
    @EnableAutoConfiguration
    @ComponentScan
    public class Application {
    
        public static void main(String[] args) {
            SpringApplication.run(Application.class,args);
        }
    }

    5.2 @RestController and @RequestMapping是springMVC的注解,不是springboot特有的注解

    即 @RestController = @Controller+@ResponseBody

    @RestController
    public class Example {
    
        @RequestMapping("/")
        String home() {
            return "Hello World!";
        }
        
        @RequestMapping("/test")
        public Map<String, String> map(){
            Map<String, String> map = new HashMap<String, String>();
            map.put("name","张三");
            map.put("age","25");
            
            
            return map;
        }
    }
    //等同于:
    @Controller
    public class Example {
        @RequestMapping("/")
        @ResponseBody
        String home() {
            return "Hello World!";
        }    
        @RequestMapping("/test")
        @ResponseBody
        public Map<String, String> map(){
            Map<String, String> map = new HashMap<String, String>();
            map.put("name","张三");
            map.put("age","25");    
            return map;
        }
    }

    6.启动项目

     

    7.常用json框架Jackson返回结果的处理

      指定字段不返回:@JsonIgnore//响应中不展示

      指定返回日期格式:@JsonFormat(pattern="yyyy-MM-dd hh:mm:ss",locale="zh",timezone="GMT+8")

      空字段不返回:@JsonInclude(Include.NON_NULL)

      响应中指定别名:@JsonProperty

    8.后续补充

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  • 原文地址:https://www.cnblogs.com/xiaozhaoboke/p/11831798.html
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