学习笔记——SpringMVC消息转换器概述；使用消息转换器处理请求报文；使用消息转换器处理响应报文；使用消息转换器处理Json格式数据

final static String SUCCESS = "success";
    @RequestMapping("/testRequestBody")
    public String testRequestBody(@RequestBody String reqBody){
        System.out.println("reqBody = " + reqBody);
        return SUCCESS;
    }

@RequestMapping("/testHttpEntity")
    public String testHttpEntity(HttpEntity<String> httpEntity){
        //获取请求头
        System.out.println("httpEntity.getHeaders() = " + httpEntity.getHeaders());
        //获取内容
        System.out.println("httpEntity.getBody() = " + httpEntity.getBody());
        return SUCCESS;
    }

@RequestMapping("/testResponseBody")
    @ResponseBody
    public String testResponseBody(){
        System.out.println("testResponseBody !!!");
        return "hello";
    }

<!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-databind -->
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.12.3</version>
</dependency>

@RequestMapping("/testJSON")
    @ResponseBody
    public Employee testJSON(){
        System.out.println("testJSON");
        Employee employee = new Employee(1001,"zhangsan","123@163.com",1);
        return employee;
    }