传参

http 状态码

（1）200： 响应成功

（2）404 ：资源找不到 - 路径错误（URL错了）

（3）405： 请求方式没有对应好（type=Method Not Allowed, status=405）

（4）400： 请求的参数与服务器类型不匹配

（5）500： 服务器后端代码出错了(出现了Exception)

JavaBean : 实体类 （1）无参构造函数（2）属性有get,set方法

传参方式

（1）URL请求参数 key 与 方法中的形参名一致

  // http://localhost:8080/app/fun1?username=smith&userAge=20
    @GetMapping("fun1")
    @ResponseBody
    public String fun1(String username,Integer userAge){

        System.out.println(username);
        System.out.println(userAge);
        return "fun1";
    }

（2）URL请求参数 key与@RequestParam(“id”) 中的别名一致

@RequestParam： URL请求参数 key与@RequestParam(“id”) 中的别名一致

//  http://localhost:8080/app/fun2?id=101&username=小林&telno=18943049303  
@GetMapping("fun2")
    @ResponseBody
    public String fun2(@RequestParam("id") Integer addrId,
                       @RequestParam("telno")Long receiveUserTelno,
                       @RequestParam("username")String receiveUsername){

        String result = "addrId:" + addrId + "receiveUsername:" + receiveUsername + "receiveUserTelno :"+receiveUserTelno;
        return result;
    }

（3） 形参是POJO类，URL 参数 key 与pojo类的 set方法一致

参数是pojo类， 要有（1）构造函数 （2）get,set

URL 参数 key 与pojo类的 set方法一致（set方法名去除set单词后，首字母小写）

底层执行原理

（1）通过反射创建ReceiveAddress对象

（2）通过反射调用set方法赋值

   @GetMapping("fun3")
    @ResponseBody
    public ReceiveAddress fun3(ReceiveAddress address){ // javabean (pojo)： 无参构造函数 + get，set
        return address;
    }

（4）参数属于URL一部分，作为路径上的变量

参数属于URL一部分，作为路径上的变量

//URL : http://localhost:8080/app/receiveAddress/103

  @GetMapping("{addrId}")  
  @ResponseBody // 返回json数据
  public ReceiveAddress getById(@PathVariable("addrId") Integer addrId){        
  	return null;
  }

ReceiveAddress.java

package com.example.entity;

import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import java.io.Serializable;
import java.time.LocalDateTime;

@TableName("receive_address")
public class ReceiveAddress implements Serializable {

    private static final long serialVersionUID = 1L;

    @TableId(value = "addr_id", type = IdType.AUTO)
    private Integer addrId;

    private Long receiveUserTelno;

    private String username;

    private Integer custId;

    /**
     * 地址的省份
     */
    private String addrProvince;

    /**
     * 地址的城市
     */
    private String addrCity;

    /**
     * 地址的区域
     */
    private String addrArea;

    /**
     * 地址的街道
     */
    private String addrStreet;

    /**
     * 详细地址
     */
    private String addrDetail;

    /**
     * 状态
     */
    private Integer status;

    /**
     * 版本号，用于做乐观锁
     */
    private Integer version;

    /**
     * 数据添加的时间
     */
    private LocalDateTime createTime;

    /**
     * 数据修改时间
     */
    private LocalDateTime updateTime;




    public ReceiveAddress(Integer addrId, Long receiveUserTelno, String receiveUsername, Integer custId, String addrProvince, String addrCity, String addrArea, String addrStreet, String addrDetail, Integer status, Integer version, LocalDateTime createTime, LocalDateTime updateTime) {
        System.out.println("调用ReceiveAddress 的有参构造函数>>>>>>>>>>>>>>>.");
        this.addrId = addrId;
        this.receiveUserTelno = receiveUserTelno;
        this.username = receiveUsername;
        this.custId = custId;
        this.addrProvince = addrProvince;
        this.addrCity = addrCity;
        this.addrArea = addrArea;
        this.addrStreet = addrStreet;
        this.addrDetail = addrDetail;
        this.status = status;
        this.version = version;
        this.createTime = createTime;
        this.updateTime = updateTime;
    }

    public Integer getAddrId() {
        return addrId;
    }

    public void setAddrId(Integer addrId) {
        this.addrId = addrId;
    }
    public Long getReceiveUserTelno() {
        return receiveUserTelno;
    }

    public void setReceiveUserTelno(Long receiveUserTelno) {
        this.receiveUserTelno = receiveUserTelno;
    }
    public String getReceiveUsername() {
        return username;
    }

    public void setReceiveUsername(String receiveUsername) {
        System.out.println(".................调用了setReceiveUsername");
        this.username = receiveUsername;
    }
    public Integer getCustId() {
        return custId;
    }

    public void setCustId(Integer custId) {
        this.custId = custId;
    }
    public String getAddrProvince() {
        return addrProvince;
    }

    public void setAddrProvince(String addrProvince) {
        this.addrProvince = addrProvince;
    }
    public String getAddrCity() {
        return addrCity;
    }

    public void setAddrCity(String addrCity) {
        this.addrCity = addrCity;
    }
    public String getAddrArea() {
        return addrArea;
    }

    public void setAddrArea(String addrArea) {
        this.addrArea = addrArea;
    }
    public String getAddrStreet() {
        return addrStreet;
    }

    public void setAddrStreet(String addrStreet) {
        this.addrStreet = addrStreet;
    }
    public String getAddrDetail() {
        return addrDetail;
    }

    public void setAddrDetail(String addrDetail) {
        this.addrDetail = addrDetail;
    }
    public Integer getStatus() {
        return status;
    }

    public void setStatus(Integer status) {
        this.status = status;
    }
    public Integer getVersion() {
        return version;
    }

    public void setVersion(Integer version) {
        this.version = version;
    }
    public LocalDateTime getCreateTime() {
        return createTime;
    }

    public void setCreateTime(LocalDateTime createTime) {
        this.createTime = createTime;
    }
    public LocalDateTime getUpdateTime() {
        return updateTime;
    }

    public void setUpdateTime(LocalDateTime updateTime) {
        this.updateTime = updateTime;
    }

    @Override
    public String toString() {
        return "ReceiveAddress{" +
            "addrId=" + addrId +
            ", receiveUserTelno=" + receiveUserTelno +
            ", receiveUsername=" + username +
            ", custId=" + custId +
            ", addrProvince=" + addrProvince +
            ", addrCity=" + addrCity +
            ", addrArea=" + addrArea +
            ", addrStreet=" + addrStreet +
            ", addrDetail=" + addrDetail +
            ", status=" + status +
            ", version=" + version +
            ", createTime=" + createTime +
            ", updateTime=" + updateTime +
        "}";
    }
}

通过反射生成对象，并给对象赋值

 /*
            ReceiveAddress address
            1. 创建对象
            2. 属性赋值

            new : 创建对象
            构造函数的作用： 初始化对象 initial
        */

//        ReceiveAddress address = new ReceiveAddress();
//        address.setReceiveUsername("smith");

       //  （1）通过反射创建ReceiveAddress 对象  -- 前提：ReceiveAddress 有无参构造函数
        ReceiveAddress address =   ReceiveAddress.class.newInstance();  // 会调用 无参构造函数

        //(2) 通过反射调用set方法 setReceiveUsername(String)
       Method method =  ReceiveAddress.class.getMethod("setReceiveUsername",String.class);
        method.invoke(address,"dd");

传参

package com.example.controller;

import com.example.entity.ReceiveAddress;
import org.springframework.stereotype.Controller;
import org.springframework.stereotype.Service;
import org.springframework.web.bind.annotation.*;

import java.util.Locale;

/**
 * 请求的相关参数
 */
@Controller
public class HelloController {


    // http://localhost:8080/app/fun1?username=smith&userAge=20
    @GetMapping("fun1")
    @ResponseBody
    public String fun1(String username,Integer userAge){

        System.out.println(username);
        System.out.println(userAge);
        return "fun1";
    }

    @GetMapping("fun2")
    @ResponseBody
    public String fun2(@RequestParam("id") Integer addrId,
                       @RequestParam("telno")Long receiveUserTelno,
                       @RequestParam("username")String receiveUsername){

        String result = "addrId:" + addrId + "receiveUsername:" + receiveUsername + "receiveUserTelno :"+receiveUserTelno;
        return result;
    }


    // http://localhost:8080/app/fun3?addrId=101&receiveUsername=%E5%B0%8F%E7%8E%8B&receiveUserTelno=18943049303

    // 实参的key 与 pojo的属性名相同
    // 面向对象 + 反射

    /**
     * （1）通过反射创建ReceiveAddress 对象  -- 前提：ReceiveAddress 调用无参构造函数
     * （2）通过反射set方法，参数赋值

     */
    @GetMapping("fun3")
    @ResponseBody
    public ReceiveAddress fun3(ReceiveAddress address){ // javabean (pojo)： 无参构造函数 + get，set
        return address;
    }

    /*
        Customer (custId,custName,custPwd --- getters,setters)
        URL : ....?custId=101&custName=smith&custPwd=abc123

     */


    @GetMapping("{addrId}")  //URL :  http://localhost:8080/app/receiveAddress/103
    @ResponseBody // 返回json数据
    public ReceiveAddress getById(@PathVariable("addrId") Integer addrId){
        return null;
    }





}