Web后端开发-请求响应
文章目录
- 概述
- 请求
- Postman
- 简单参数
- 原始方式
- SpringBoot
- @RequestParam注解
- 小结
- 实体参数
- 数组集合参数
- 日期参数
- Json参数
- 路径参数
- 总结
- 响应
- 响应-案例
概述
请求
Postman
简单参数
原始方式
// 1. 简单参数
// 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";}
SpringBoot
// springboot方式@RequestMapping("/simpleParam")public String simpleParam(String name, Integer age){System.out.println(name+ ":" + age);return "OK";}@RequestMapping("/simpleParam")public String simpleParam(String username, Integer age){System.out.println(username+ ":" + age);return "OK";}
@RequestParam注解
@RequestMapping("/simpleParam")public String simpleParam(@RequestParam(name = "name") String username, Integer age){System.out.println(username+ ":" + age);return "OK";}
@RequestMapping("/simpleParam")public String simpleParam(@RequestParam(name = "name",required = false) String username, Integer age){System.out.println(username+ ":" + age);return "OK";}
小结
实体参数
//2. 实体参数@RequestMapping("/simplePojo")public String simplePojo(User user){System.out.println(user);return "OK";}
@RequestMapping("/complexPojo")public String complexPojo(User user){System.out.println(user);return "OK";}
数组集合参数
//3. 数组集合参数@RequestMapping("/arrayParam")public String arrayParam(String[] hobby){System.out.println(Arrays.toString(hobby));return "OK";}@RequestMapping("/listParam")public String listParam(@RequestParam List<String> hobby){System.out.println(hobby);return "OK";}
日期参数
//4. 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
//5. json参数@RequestMapping("/jsonParam")public String jsonParam(@RequestBody User user){System.out.println(user);return "OK";}
路径参数
//6. 路径参数@RequestMapping("/path/{id}")public String pathParam(@PathVariable Integer id){System.out.println(id);return "OK";}@RequestMapping("/path/{id}/{name}")public String pathParam2(@PathVariable Integer id , @PathVariable String name){System.out.println(id);System.out.println(name);return "OK";}
总结
package com.itheima.controller;import com.itheima.pojo.User;
import org.springframework.format.annotation.DateTimeFormat;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.*;import javax.servlet.http.HttpServletRequest;
import java.time.LocalDateTime;
import java.util.Arrays;
import java.util.List;/*** 测试请求参数接收*/
@RestController
//@Controller
//@ResponseBody
public class RequestController { 1. 简单参数
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";
// }
//
springboot方式
// @RequestMapping("/simpleParam")
// public String simpleParam(String name, Integer age){
// System.out.println(name+ ":" + age);
// return "OK";
// }
//
// @RequestMapping("/simpleParam")
// public String simpleParam(String username, Integer age){
// System.out.println(username+ ":" + age);
// return "OK";
// }@RequestMapping("/simpleParam")public String simpleParam(@RequestParam(name = "name",required = false) String username, Integer age){System.out.println(username+ ":" + age);return "OK";}//2. 实体参数@RequestMapping("/simplePojo")public String simplePojo(User user){System.out.println(user);return "OK";}@RequestMapping("/complexPojo")public String complexPojo(User user){System.out.println(user);return "OK";}//3. 数组集合参数@RequestMapping("/arrayParam")public String arrayParam(String[] hobby){System.out.println(Arrays.toString(hobby));return "OK";}@RequestMapping("/listParam")public String listParam(@RequestParam List<String> hobby){System.out.println(hobby);return "OK";}//4. 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";}//5. json参数@RequestMapping("/jsonParam")public String jsonParam(@RequestBody User user){System.out.println(user);return "OK";}//6. 路径参数@RequestMapping("/path/{id}")public String pathParam(@PathVariable Integer id){System.out.println(id);return "OK";}@RequestMapping("/path/{id}/{name}")public String pathParam2(@PathVariable Integer id , @PathVariable String name){System.out.println(id);System.out.println(name);return "OK";}
}
响应
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;}
}
Result
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 +'}';}
}
ResponseController
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 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);}
}
响应-案例
XML文件
<?xml version="1.0" encoding="UTF-8" ?>
<emps><emp><name>金毛狮王</name><age>55</age><image>https://web-framework.oss-cn-hangzhou.aliyuncs.com/web/1.jpg</image><!-- 1: 男, 2: 女 --><gender>1</gender><!-- 1: 讲师, 2: 班主任 , 3: 就业指导 --><job>1</job></emp><emp><name>白眉鹰王</name><age>65</age><image>https://web-framework.oss-cn-hangzhou.aliyuncs.com/web/2.jpg</image><gender>1</gender><job>1</job></emp><emp><name>青翼蝠王</name><age>45</age><image>https://web-framework.oss-cn-hangzhou.aliyuncs.com/web/3.jpg</image><gender>1</gender><job>2</job></emp><emp><name>紫衫龙王</name><age>38</age><image>https://web-framework.oss-cn-hangzhou.aliyuncs.com/web/4.jpg</image><gender>2</gender><job>3</job></emp>
</emps>
Emp
package com.itheima.pojo;public class Emp {private String name;private Integer age;private String image;private String gender;private String job;public Emp() {}public Emp(String name, Integer age, String image, String gender, String job) {this.name = name;this.age = age;this.image = image;this.gender = gender;this.job = job;}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 String getImage() {return image;}public void setImage(String image) {this.image = image;}public String getGender() {return gender;}public void setGender(String gender) {this.gender = gender;}public String getJob() {return job;}public void setJob(String job) {this.job = job;}@Overridepublic String toString() {return "Emp{" +"name='" + name + '\'' +", age=" + age +", image='" + image + '\'' +", gender='" + gender + '\'' +", job='" + job + '\'' +'}';}
}
XmlParserUtils
package com.itheima.utils;import org.dom4j.Document;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;
import java.io.File;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.List;public class XmlParserUtils {public static <T> List<T> parse(String file , Class<T> targetClass) {ArrayList<T> list = new ArrayList<T>(); //封装解析出来的数据try {//1.获取一个解析器对象SAXReader saxReader = new SAXReader();//2.利用解析器把xml文件加载到内存中,并返回一个文档对象Document document = saxReader.read(new File(file));//3.获取到根标签Element rootElement = document.getRootElement();//4.通过根标签来获取 user 标签List<Element> elements = rootElement.elements("emp");//5.遍历集合,得到每一个 user 标签for (Element element : elements) {//获取 name 属性String name = element.element("name").getText();//获取 age 属性String age = element.element("age").getText();//获取 image 属性String image = element.element("image").getText();//获取 gender 属性String gender = element.element("gender").getText();//获取 job 属性String job = element.element("job").getText();//组装数据Constructor<T> constructor = targetClass.getDeclaredConstructor(String.class, Integer.class, String.class, String.class, String.class);constructor.setAccessible(true);T object = constructor.newInstance(name, Integer.parseInt(age), image, gender, job);list.add(object);}} catch (Exception e) {e.printStackTrace();}return list;}}
以下详细解释加载并解析emp.xml部分的代码
- 加载XML文件
String file = this.getClass().getClassLoader().getResource("emp.xml").getFile();
this.getClass().getClassLoader()
:获取当前类的类加载器。类加载器负责加载类文件,但在这里它的作用是通过getResource方法查找资源文件。
getResource("emp.xml")
:通过类加载器查找名为emp.xml的资源文件。这个文件通常位于项目的resources目录下(如果是基于Maven或Gradle的项目结构)。getResource方法会返回一个URL对象,表示资源文件的路径。
.getFile()
:从URL对象中提取文件路径字符串。这个路径可能是相对路径或绝对路径,具体取决于运行环境。例如,在某些情况下,它可能会返回类似file:/path/to/emp.xml这样的路径。
2. 打印文件路径
System.out.println(file);
这行代码将打印出emp.xml文件的路径。这通常用于调试,帮助开发者确认文件是否被正确加载。
3. 解析XML文件
List<Emp> empList = XmlParserUtils.parse(file, Emp.class);
XmlParserUtils.parse(file, Emp.class)
:这是一个工具方法,用于解析XML文件并将解析结果转换为指定类的对象列表。具体实现细节取决于XmlParserUtils类的定义,但通常会涉及以下步骤:
读取XML文件内容
:使用文件路径file打开并读取emp.xml文件的内容。
解析XML
:使用XML解析技术(如DOM、SAX或JAXB)解析XML文件。解析器会根据XML文件的结构和内容提取数据。
映射到Java对象
:将解析出的数据映射到Emp类的实例中。Emp.class指定了目标类的类型,解析器会根据Emp类的字段和XML的结构进行数据绑定。
返回对象列表
:最终返回一个包含Emp对象的列表empList。
4. Emp类的作用
Emp类是这段代码中提到的一个Java类,它应该是用来表示emp.xml文件中定义的员工信息的。例如:
public class Emp {private String name;private int age;private String department;// Getters and Setters
}
XML文件中可能包含类似以下结构的内容:
<employees><emp><name>John Doe</name><age>30</age><department>HR</department></emp><emp><name>Jane Smith</name><age>25</age><department>IT</department></emp>
</employees>
解析器会根据XML的结构将每个元素映射为一个Emp对象,并将这些对象存储在empList列表中。
5. 总结
这段代码的主要作用是:
通过类加载器加载emp.xml文件并获取其路径。
使用XmlParserUtils.parse方法解析XML文件,并将解析结果转换为Emp对象列表。
打印文件路径以确认文件被正确加载。
这种代码模式在处理基于XML配置或数据存储的场景中非常常见,例如加载配置文件或解析数据文件。
EmpController
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);}}