当前位置：首页 > news >正文

8.6 JavaWeb（请求响应 P67-P74）

news 2025/8/7 5:54:06

BS架构：Browser/Response，浏览器/服务器架构模式，客户端只需要浏览器，应用程序的逻辑和数据存储在服务端（维护方便，体验一般）

CS架构：Client/Server，客户端/服务器架构模式（开发、维护麻烦，但体验好）

请求

Postman

Postman是一款功能强大的网页调试与发送网页HTTP请求的Chrome插件，常用于进行接口测试

官网下载即可：Download Postman | Get Started for Free

注意注册时需要科学上网

简单参数

1.原始方式：在原始的Web程序中，获取请求参数，需要通过HttpServletRequest对象手动获取

package com.itheima.controller;import jakarta.servlet.http.HttpServletRequest;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;/*** 测试请求参数接收*/
@RestController
public class RequestController {//原始方式@RequestMapping("/simpleParam")public String simpleParam(HttpServletRequest request) {//获取请求参数String name = request.getParameter("name");String ageStr = request.getParameter("age");int  age = Integer.parseInt(ageStr);System.out.println(name + ":" + age);return "OK";}
}

运行启动程序，在Postman中访问URL：http://localhost:8080/simpleParam?name=Tom&age=10

原始方式仅作了解即可，较繁琐且需要手动类型转换

2.SpringBoot方式：

若参数名与形参名相同，定义形参即可接收参数

@RestController
public class RequestController {//SpringBoot方式@RequestMapping("/simpleParam")public String simpleParam(String name, Integer age) {System.out.println(name + ":" + age);return "OK";}
}

若方法形参名称与请求参数名称不匹配，可以使用@RequestParam完成映射

@RestController
public class RequestController {//SpringBoot方式@RequestMapping("/simpleParam")public String simpleParam(@RequestParam(name="name", required = false) String username, Integer age) {System.out.println(username + ":" + age);return "OK";}
}

该注解的required属性默认为true，代表请求参数必须传递，如果没有传递则会报错，如果修改为false，则该参数不传递也可以正常运行（可选），该参数值为null

实体参数

实体参数对象：

简单实体对象：请求参数名与形参对象属性名相同，定义POJO接收即可

先定义User类封装name和age

package com.itheima.pojo;public class User {private String name;private Integer age;public String getName() {return name;}public void setName(String name) {this.name = name;}public Integer getAge() {return age;}public void setAge(Integer age) {this.age = age;}@Overridepublic String toString() {return "User{" +"name='" + name + '\'' +", age=" + age +'}';}
}

再定义注解

package com.itheima.controller;import com.itheima.pojo.User;
import jakarta.servlet.http.HttpServletRequest;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;@RestController
public class RequestController {//SpringBoot方式@RequestMapping("/simpleParam")public String simpleParam(@RequestParam(name="name", required = false) String username, Integer age) {System.out.println(username + ":" + age);return "OK";}//实体参数@RequestMapping("/simplePojo")public String simplePojo(User user) {System.out.println(user);return "OK";}
}

使用get方式访问/simplePojo

复杂实体对象：请求参数名与形参对象属性名相同，按照对象层次结构关系即可接收嵌套POJO属性参数

package com.itheima.pojo;public class Address {private String province;private String city;public String getProvince() {return province;}public void setProvince(String province) {this.province = province;}public String getCity() {return city;}public void setCity(String city) {this.city = city;}@Overridepublic String toString() {return "Address{" +"province='" + province + '\'' +", city='" + city + '\'' +'}';}
}

package com.itheima.pojo;public class User {private String name;private Integer age;private Address address;public String getName() {return name;}public void setName(String name) {this.name = name;}public Integer getAge() {return age;}public void setAge(Integer age) {this.age = age;}public Address getAddress() {return address;}public void setAddress(Address address) {this.address = address;}@Overridepublic String toString() {return "User{" +"name='" + name + '\'' +", age=" + age +", address=" + address +'}';}
}

//实体参数@RequestMapping("/complexPojo")public String ComplexPojo(User user) {System.out.println(user);return "OK";}

数组集合参数

数组参数：请求参数名与形参数组名称相同且请求参数为多个，定义数组类型形参即可接收参数

//数组参数@RequestMapping("/arrayParam")public String arrayParam(String[] hobby) {System.out.println(Arrays.toString(hobby));return "OK";}

集合参数：请求参数名与形参集合名称相同且请求参数为多个，@RequestParam绑定参数关系

//集合参数@RequestMapping("/listParam")public String listParam(@RequestParam List<String> hobby) {System.out.println(hobby);return "OK";}

日期参数

使用@DateTimeFormat注解完成日期参数格式转换

//日期时间参数@RequestMapping("/dateParam")public String dateParam(@DateTimeFormat(pattern = "yyyy-MM-dd HH:mm:ss") LocalDateTime updateTime) {System.out.println(updateTime);return "OK";}

Json参数

Json数据键名与形参对象属性名相同，定义Pojo类型形参即可接收参数，需要使用@RequestBody标识

//json参数@RequestMapping("/jsonParam")public String jsonParam(@RequestBody User user) {System.out.println(user);return "OK";}

路径参数

通过URL直接传递参数，使用{...}来标识该路径参数，需要使用@PathVariable获取路径参数

//路径参数@RequestMapping("/path/{id}")public String pathParam(@PathVariable Integer id) {System.out.println(id);return "OK";}//路径参数@RequestMapping("/path/{id}/{name}")public String pathParam2(@PathVariable Integer id, @PathVariable String name) {System.out.println(id + ":" + name);return "OK";}

响应

@ResponseBody注解

类型：方法注解、类注解

位置：Controller方法/类上

作用：将方法返回值直接响应，如果返回值类型是实体对象/集合，将会转换成Json格式响应

说明：@RestController = @Controller + @ResponseBody

统一响应结果

package com.itheima.pojo;/*** 统一响应结果封装类*/
public class Result {private Integer code ;//1 成功 , 0 失败private String msg; //提示信息private Object data; //数据 datepublic Result() {}public Result(Integer code, String msg, Object data) {this.code = code;this.msg = msg;this.data = data;}public Integer getCode() {return code;}public void setCode(Integer code) {this.code = code;}public String getMsg() {return msg;}public void setMsg(String msg) {this.msg = msg;}public Object getData() {return data;}public void setData(Object data) {this.data = data;}public static Result success(Object data){return new Result(1, "success", data);}public static Result success(){return new Result(1, "success", null);}public static Result error(String msg){return new Result(0, msg, null);}@Overridepublic String toString() {return "Result{" +"code=" + code +", msg='" + msg + '\'' +", data=" + data +'}';}
}

package com.itheima.controller;import com.itheima.pojo.Address;
import com.itheima.pojo.Result;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import java.util.ArrayList;
import java.util.List;/*** 测试响应数据*/
@RestController
public class ResponseController {/*@RequestMapping("/hello")public String hello(){System.out.println("Hello World ~");return "Hello World ~";}@RequestMapping("/getAddr")public Address getAddr(){Address addr = new Address();addr.setProvince("广东");addr.setCity("深圳");return addr;}@RequestMapping("/listAddr")public List<Address> listAddr(){List<Address> list = new ArrayList<>();Address addr = new Address();addr.setProvince("广东");addr.setCity("深圳");Address addr2 = new Address();addr2.setProvince("陕西");addr2.setCity("西安");list.add(addr);list.add(addr2);return list;}*/@RequestMapping("/hello")public Result hello(){System.out.println("Hello World ~");//return new Result(1,"success","Hello World ~");return Result.success("Hello World ~");}@RequestMapping("/getAddr")public Result getAddr(){Address addr = new Address();addr.setProvince("广东");addr.setCity("深圳");return Result.success(addr);}@RequestMapping("/listAddr")public Result listAddr(){List<Address> list = new ArrayList<>();Address addr = new Address();addr.setProvince("广东");addr.setCity("深圳");Address addr2 = new Address();addr2.setProvince("陕西");addr2.setCity("西安");list.add(addr);list.add(addr2);return Result.success(list);}
}

案例

需求：加载并解析emp.xml文件中的数据，完成数据处理，并在页面展示

分析：1.在pom.xml文件中引入dom4j的依赖，用于解析xml文件

2.引入资料中提供的解析XML的工具类XMLParserUtils、对应的实体类Emp、XML文件emp.xml

3.引入资料中提供的静态页面文件，放在resources下的static目录下

4.编写Controller程序，处理请求，响应数据

package com.itheima.controller;import com.itheima.pojo.Emp;
import com.itheima.pojo.Result;
import com.itheima.utils.XmlParserUtils;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;import java.util.List;@RestController
public class EmpController {@RequestMapping("/listEmp")public Result list(){//1. 加载并解析emp.xmlString file = this.getClass().getClassLoader().getResource("emp.xml").getFile();System.out.println(file);List<Emp> empList = XmlParserUtils.parse(file, Emp.class);//2. 对数据进行转换处理 - gender, jobempList.stream().forEach(emp -> {//处理 gender 1: 男, 2: 女String gender = emp.getGender();if("1".equals(gender)){emp.setGender("男");}else if("2".equals(gender)){emp.setGender("女");}//处理job - 1: 讲师, 2: 班主任 , 3: 就业指导String job = emp.getJob();if("1".equals(job)){emp.setJob("讲师");}else if("2".equals(job)){emp.setJob("班主任");}else if("3".equals(job)){emp.setJob("就业指导");}});//3. 响应数据return Result.success(empList);}}