springboot接收参数详解

请求路径带参数

@PathVariable：当请求路径格式为http://ip:port/projectName/aaaaa/{xx},在方法的@RequestMapping注解里面写上@RequestMapping("user/{id}")，表示的是
请求的最后一个字符就是id的值，在方法参数里我们用@PathVariable注解取值。

//1、@PathVariable，前台请求格式为get： http://localhost:8088/moyundong/sysUser/user/10086
@RequestMapping("user/{id}")
public String selectById(@PathVariable(name = "id") String id){
    System.out.println("参数id="+id);
    return "selectById请求成功";
}

在浏览器输入http://localhost:8088/moyundong/sysUser/user/10086就能看到结果

@RequestParam：当请求路径格式为http://ip:port/projectName/aaaaa?id=10086,时，在方法参数里我们用@RequestParam注解取值。

//2、@RequestParam，前台请求格式为get： http://localhost:8088/moyundong/sysUser/selectById?id=10086
@RequestMapping("selectById")
public String selectById2(@RequestParam(name = "id") String id){
    System.out.println("参数id="+id);
    return "selectById2请求成功";
}

在浏览器输入http://localhost:8088/moyundong/sysUser/selectById?id=10086就能看到结果

@PathVariable + @RequestParam组合使用

//3、@PathVariable + @RequestParam，前台请求格式为get： http://localhost:8088/moyundong/sysUser/selectUser/10086?name=移动客服
@RequestMapping("selectUser/{id}")
public String selectByIdAndName(@PathVariable(name = "id") String id,@RequestParam(name = "name") String name){
    System.out.println("参数id="+id);
    System.out.println("参数name="+name);
    return "selectByIdAndName请求成功";
}

在浏览器输入http://localhost:8088/moyundong/sysUser/selectUser/10086?name=移动客服

不加任何注解的时候，如果用?传值，直接在方法参数里使用相同变量名接收就行。

//不加注解，前台请求格式为get： http://localhost:8088/moyundong/sysUser/selectUser2?id=10086&name=移动客服
@RequestMapping("selectUser2")
public String selectByIdAndName2(String id, String name){
    System.out.println("参数id="+id);
    System.out.println("参数name="+name);
    return "selectByIdAndName2请求成功";
}

对象参数

先定义一个实体对象类SysUser

@Data
public class SysUser {
    private String id;
    private String username;
    private String password;
    private Date birthday;
    private String email;
}

post请求，参数格式是json，使用@RequestBody注解然后直接用对象接收参数，这种前台一般是ajax请求

@PostMapping(path = "/addUser")
public String addUser(@RequestBody SysUser sysUser) {
    System.out.println(sysUser.toString());
    return "addUser请求成功";
}

页面请求url：http://localhost:8088/moyundong/sysUser/addUser
参数：{"id":"10086","password":"123456","birthday":"2019-09-09","username":"admin","email":"aa@aa.com"}

2. post请求，参数格式是表单数据，在postman里面就是form-data格式

//参数是表单格式在postman里面就是form-data格式，这个里面日期类型传2019/08/08，与json格式不一样，json格式日期要传为2019-08-08格式。
@PostMapping(path = "/addUser2")
public String addUser2(SysUser sysUser) {
    System.out.println(sysUser.toString());
    return "addUser2请求成功";
}

页面请求url：http://localhost:8088/moyundong/sysUser/addUser2
参数：{"id":"10086","password":"123456","birthday":"2019-09-09","username":"admin","email":"aa@aa.com"}

::: warning 注意

json格式传递日期类型的时候使用YYYY-MM-DD，例如2019-09-09
表单（form-data格式）传递日期类型的时候使用YYYY/MM/DD，例如2019/08/08
这个是我们没有使用formate的情况，使用formate的话就根据自定义类型传递就可以了。
:::

header以及Cookie

使用@RequestHeader和@CookieValue获取请求头和cookie的信息

@GetMapping("getCookieAndHeader")
public String getCookieAndHeader(@RequestHeader(name = "myHeader") String myHeader,
                  @CookieValue(name = "myCookie") String myCookie) {
    System.out.println("myHeader=" + myHeader);
    System.out.println("myCookie=" + myCookie);
    return "getCookieAndHeader请求成功";
}

HttpServletRequest接收参数

通过request获取header和cookie

//1 通过request获取header和cookie
@GetMapping("/getCookieAndHeader2")
public String getCookieAndHeader2(HttpServletRequest request) {
    System.out.println("myHeader=" + request.getHeader("myHeader"));
    for (Cookie cookie : request.getCookies()) {
        if ("myCookie".equals(cookie.getName())) {
            System.out.println("myCookie=" + cookie.getValue());
        }
    }
    return "getCookieAndHeader2请求成功";
}

通过request获取普通参数，post和get方法都可以获取到

// http://localhost:8088/moyundong/sysUser/addUser3?username=water&password=123456
@RequestMapping("/addUser3")
public String addUser3(HttpServletRequest request) {
    String username=request.getParameter("username");
    String password=request.getParameter("password");
    System.out.println("username = "+username);
    System.out.println("password = "+password);
    return "addUser3请求成功";
}

::: tip 提示
理论上所有参数都是可以通过request获取，只不过使用不同的方法罢了。
:::

测试的controller贴到下面

package com.moyundong.controller;

import com.moyundong.entity.SysUser;
import org.springframework.web.bind.annotation.*;

import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;

/**
 * @Author: www.moyundong.com
 * @Date：2020-06-13 00:56:37
 * @Description: TODO
 **/
@RestController
@RequestMapping("sysUser")
public class SysUserController {
    //第一类：请求路径参数
    //1、@PathVariable，前台请求格式为get： http://localhost:8088/moyundong/sysUser/user/10086
    @RequestMapping("user/{id}")
    public String selectById(@PathVariable(name = "id") String id){
        System.out.println("参数id="+id);
        return "selectById请求成功";
    }
    //2、@RequestParam，前台请求格式为get： http://localhost:8088/moyundong/sysUser/selectById?id=10086
    @RequestMapping("selectById")
    public String selectById2(@RequestParam(name = "id") String id){
        System.out.println("参数id="+id);
        return "selectById2请求成功";
    }
    //3、@PathVariable + @RequestParam，前台请求格式为get： http://localhost:8088/moyundong/sysUser/selectUser/10086?name=移动客服
    @RequestMapping("selectUser/{id}")
    public String selectByIdAndName(@PathVariable(name = "id") String id,@RequestParam(name = "name") String name){
        System.out.println("参数id="+id);
        System.out.println("参数name="+name);
        return "selectByIdAndName请求成功";
    }
    //不加注解，前台请求格式为get： http://localhost:8088/moyundong/sysUser/selectUser2?id=10086&name=移动客服
    @RequestMapping("selectUser2")
    public String selectByIdAndName2(String id, String name){
        System.out.println("参数id="+id);
        System.out.println("参数name="+name);
        return "selectByIdAndName2请求成功";
    }

    //**********第二类：对象参数*****************
    //1、@RequestBody，前台是post请求，参数格式是json
    //http://localhost:8088/moyundong/sysUser/addUser
    //{"id":"10086","password":"123456","birthday":"2019-09-09","username":"admin","email":"aa@aa.com"}
    @PostMapping(path = "/addUser")
    public String addUser(@RequestBody SysUser sysUser) {
        System.out.println(sysUser.toString());
        return "addUser请求成功";
    }

    //2、无参数前台是post请求，参数格式是表单
    //http://localhost:8088/moyundong/sysUser/addUser2
    //参数是表单格式在postman里面就是form-data格式，这个里面日期类型传2019/08/08，与json格式不一样，json格式日期要传为2019-08-08格式。
    @PostMapping(path = "/addUser2")
    public String addUser2(SysUser sysUser) {
        System.out.println(sysUser.toString());
        return "addUser2请求成功";
    }

    // 第三类：请求头参数以及Cookie
    @GetMapping("getCookieAndHeader")
    public String getCookieAndHeader(@RequestHeader(name = "myHeader") String myHeader,
                      @CookieValue(name = "myCookie") String myCookie) {
        System.out.println("myHeader=" + myHeader);
        System.out.println("myCookie=" + myCookie);
        return "getCookieAndHeader请求成功";
    }

    // 第四类：HttpServletRequest接收
    //1 通过request获取header和cookie
    @GetMapping("/getCookieAndHeader2")
    public String getCookieAndHeader2(HttpServletRequest request) {
        System.out.println("myHeader=" + request.getHeader("myHeader"));
        for (Cookie cookie : request.getCookies()) {
            if ("myCookie".equals(cookie.getName())) {
                System.out.println("myCookie=" + cookie.getValue());
            }
        }
        return "getCookieAndHeader2请求成功";
    }

    //2 通过request获取普通参数，post和get方法都可以获取到
    // http://localhost:8088/moyundong/sysUser/addUser3?username=water&password=123456
    @RequestMapping("/addUser3")
    public String addUser3(HttpServletRequest request) {
        String username=request.getParameter("username");
        String password=request.getParameter("password");
        System.out.println("username = "+username);
        System.out.println("password = "+password);
        return "addUser3请求成功";
    }
}