003 传参

文章目录

传参
- http 状态码
- 传参方式
- - （1）URL请求参数 key 与方法中的形参名一致
  - （2）URL请求参数 key与@RequestParam("id") 中的别名一致
  - （3）形参是POJO类，URL 参数 key 与pojo类的 set方法一致
  - （4）参数属于URL一部分，作为路径上的变量
- ReceiveAddress.java
- 通过反射生成对象，并给对象赋值
- 传参

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")@ResponseBodypublic 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")@ResponseBodypublic 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")@ResponseBodypublic ReceiveAddress fun3(ReceiveAddress address){ // javabean (pojo)： 无参构造函数 + get，setreturn 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;}@Overridepublic 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 address1. 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")@ResponseBodypublic String fun1(String username,Integer userAge){System.out.println(username);System.out.println(userAge);return "fun1";}@GetMapping("fun2")@ResponseBodypublic 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")@ResponseBodypublic ReceiveAddress fun3(ReceiveAddress address){ // javabean (pojo)： 无参构造函数 + get，setreturn 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;}}