• JavaWeb开发-05-SpringBootWeb请求响应

     

    一.请求

    1.Postman


    2.简单参数

    ​

    1. package com.wjh.controller;
    2.  
    3.  
    4. import org.springframework.web.bind.annotation.RequestMapping;
    5. import org.springframework.web.bind.annotation.RestController;
    6.  
    7. import javax.servlet.http.HttpServletRequest;
    8.  
    9. /*
    10.  *   测试请求参数接受
    11.  */
    12. @RestController
    13. public class RequestController {
    14.  
    15. //    //原始方式
    16. //    @RequestMapping ("/simpleParam")
    17. //    public String simpleParam(HttpServletRequest request){
    18. //        //获取请求参数
    19. //        String name = request.getParameter("name");
    20. //        String ageStr = request.getParameter("age");
    21. //
    22. //        int age = Integer.parseInt(ageStr);
    23. //        System.out.println(name + ":" + age + ":");
    24. //
    25. //        return "OK!";
    26. //    }
    27.  
    28.     //springboot 方式
    29.     @RequestMapping ("/simpleParam")
    30.     public String simpleParam( String name,Integer age){
    31.         System.out.println(name + ":" + age + ":");
    32.         return "OK!";
    33.     }
    34. }

    ​

     ​

     ​

     GET请求:

     ​

     ​

     POST请求:

     ​

     ​

    ​

    ​

    ​

     ​

    1. package com.wjh.controller;
    2.  
    3.  
    4. import org.springframework.web.bind.annotation.RequestMapping;
    5. import org.springframework.web.bind.annotation.RequestParam;
    6. import org.springframework.web.bind.annotation.RestController;
    7.  
    8. import javax.servlet.http.HttpServletRequest;
    9.  
    10. /*
    11.  *   测试请求参数接受
    12.  */
    13. @RestController
    14. public class RequestController {
    15.  
    16. //    //原始方式
    17. //    @RequestMapping ("/simpleParam")
    18. //    public String simpleParam(HttpServletRequest request){
    19. //        //获取请求参数
    20. //        String name = request.getParameter("name");
    21. //        String ageStr = request.getParameter("age");
    22. //
    23. //        int age = Integer.parseInt(ageStr);
    24. //        System.out.println(name + ":" + age + ":");
    25. //
    26. //        return "OK!";
    27. //    }
    28.  
    29.     //springboot 方式
    30. //    @RequestMapping ("/simpleParam")
    31. //    public String simpleParam( String name,Integer age){
    32. //        System.out.println(name + ":" + age + ":");
    33. //        return "OK!";
    34. //    }
    35.     @RequestMapping ("/simpleParam")
    36.     public String simpleParam(@RequestParam(name = "name") String username, Integer age){
    37.         System.out.println(username + ":" + age + ":");
    38.         return "OK!";
    39.     }
    40. }

     

     

     

    ​

    3.实体参数

    ​

     创建一个User类:

    1. package com.wjh.pojo;
    2.  
    3. public class User {
    4.     private String name;
    5.     private Integer age;
    6.  
    7.     public String getName() {
    8.         return name;
    9.     }
    10.  
    11.     public void setName(String name) {
    12.         this.name = name;
    13.     }
    14.  
    15.     public Integer getAge() {
    16.         return age;
    17.     }
    18.  
    19.     public void setAge(Integer age) {
    20.         this.age = age;
    21.     }
    22.  
    23.     @Override
    24.     public String toString() {
    25.         return "User{" +
    26.                 "name='" + name + '\'' +
    27.                 ", age=" + age +
    28.                 '}';
    29.     }
    30. }

     

    ​

    创建一个Address类

    1. package com.wjh.pojo;
    2.  
    3. public class Address {
    4.     private String province;    //省
    5.     private String city;    //市
    6.  
    7.     public String getProvince() {
    8.         return province;
    9.     }
    10.  
    11.     public void setProvince(String province) {
    12.         this.province = province;
    13.     }
    14.  
    15.     public String getCity() {
    16.         return city;
    17.     }
    18.  
    19.     public void setCity(String city) {
    20.         this.city = city;
    21.     }
    22.  
    23.     @Override
    24.     public String toString() {
    25.         return "Address{" +
    26.                 "province='" + province + '\'' +
    27.                 ", city='" + city + '\'' +
    28.                 '}';
    29.     }
    30. }

    1. package com.wjh.controller;
    2.  
    3.  
    4. import com.wjh.pojo.User;
    5. import org.springframework.web.bind.annotation.RequestMapping;
    6. import org.springframework.web.bind.annotation.RequestParam;
    7. import org.springframework.web.bind.annotation.RestController;
    8.  
    9. import javax.servlet.http.HttpServletRequest;
    10.  
    11. /*
    12.  *   测试请求参数接受
    13.  */
    14. @RestController
    15. public class RequestController {
    16.  
    17. //    //原始方式
    18. //    @RequestMapping ("/simpleParam")
    19. //    public String simpleParam(HttpServletRequest request){
    20. //        //获取请求参数
    21. //        String name = request.getParameter("name");
    22. //        String ageStr = request.getParameter("age");
    23. //
    24. //        int age = Integer.parseInt(ageStr);
    25. //        System.out.println(name + ":" + age + ":");
    26. //
    27. //        return "OK!";
    28. //    }
    29.  
    30.     //springboot 方式
    31. //    @RequestMapping ("/simpleParam")
    32. //    public String simpleParam( String name,Integer age){
    33. //        System.out.println(name + ":" + age + ":");
    34. //        return "OK!";
    35. //    }
    36.  
    37.  
    38. //    @RequestMapping ("/simpleParam")
    39. //    public String simpleParam(@RequestParam(name = "name", required = false) String username, Integer age){
    40. //        System.out.println(username + ":" + age + ":");
    41. //        return "OK!";
    42. //    }
    43.  
    44.  
    45.  
    46.     //2.实体参http://localhost:8080/simpleParam数
    47.     @RequestMapping("/simplePojo")
    48.     public String simplePojo(User user){
    49.         System.out.println(user);
    50.         System.out.println("姓名:" + user.getName());
    51.         System.out.println("年龄:" + user.getAge());
    52.         System.out.println("省份:" + user.getAddress().getProvince());
    53.         System.out.println("城市:" + user.getAddress().getCity());
    54.         return "YES OK!";
    55.  
    56.     }
    57. }

     


     

    ​

    4.数组集合参数

    ​

    1. //3.数组集合参数
    2.     @RequestMapping("/arrayParam")
    3.     public String arrayParam(String[] hobby){
    4.         System.out.println(hobby);
    5.         System.out.println(Arrays.toString(hobby));
    6.         return "YES OK!";
    7.     }

    ​

    1. //集合参数
    2.     @RequestMapping("/listParam")
    3.     public String listParam(@RequestParam List hobby){
    4.         System.out.println(hobby);
    5.         return "YES OK!";
    6.     }

    ​


    5.日期参数

    ​

     


    6.Json参数

    ​

    1. //6.json参数
    2.     @RequestMapping("/jsonParam")
    3.     //@DateTimeFormat -> 指定时间传递的参数格式
    4.     public String jsonParam(@RequestBody User user){
    5.         System.out.println(user);
    6.         return "YES OK!";
    7.     }
    1. {
    2.     "name": "小黑子",
    3.     "age": 18,
    4.     "address": {
    5.         "province": "江西",
    6.         "city": "南昌"
    7.     }
    8. }


    7.路径参数

    ​

     

     

     

     

    1. package com.wjh.controller;
    2.  
    3.  
    4. import com.wjh.pojo.User;
    5. import org.springframework.format.annotation.DateTimeFormat;
    6. import org.springframework.web.bind.annotation.*;
    7.  
    8. import javax.servlet.http.HttpServletRequest;
    9. import java.time.LocalDate;
    10. import java.time.LocalDateTime;
    11. import java.util.Arrays;
    12. import java.util.List;
    13.  
    14. /*
    15.  *   测试请求参数接受
    16.  */
    17. @RestController
    18. public class RequestController {
    19.  
    20. //    //原始方式
    21. //    @RequestMapping ("/simpleParam")
    22. //    public String simpleParam(HttpServletRequest request){
    23. //        //获取请求参数
    24. //        String name = request.getParameter("name");
    25. //        String ageStr = request.getParameter("age");
    26. //
    27. //        int age = Integer.parseInt(ageStr);
    28. //        System.out.println(name + ":" + age + ":");
    29. //
    30. //        return "OK!";
    31. //    }
    32.  
    33.     //springboot 方式
    34.     @RequestMapping ("/simpleParam")
    35.     public String simpleParam( String name,Integer age){
    36.         System.out.println(name + ":" + age + ":");
    37.         return "OK!";
    38.     }
    39.  
    40.  
    41.     @RequestMapping ("/simpleParamF")
    42.     public String simpleParamF(@RequestParam(name = "name", required = false) String username, Integer age){
    43.         System.out.println(username + ":" + age + ":");
    44.         return "OK!";
    45.     }
    46.  
    47.  
    48.  
    49.     //2.实体参http://localhost:8080/simpleParam数
    50.     @RequestMapping("/simplePojo")
    51.     public String simplePojo(User user){
    52.         System.out.println(user);
    53.         System.out.println("姓名:" + user.getName());
    54.         System.out.println("年龄:" + user.getAge());
    55.         System.out.println("省份:" + user.getAddress().getProvince());
    56.         System.out.println("城市:" + user.getAddress().getCity());
    57.         return "YES OK!";
    58.  
    59.     }
    60.  
    61.     //3.数组参数
    62.     @RequestMapping("/arrayParam")
    63.     public String arrayParam(String[] hobby){
    64.         System.out.println(hobby);
    65.         System.out.println(Arrays.toString(hobby));
    66.         return "YES OK!";
    67.     }
    68.  
    69.     //4.集合参数
    70.     @RequestMapping("/listParam")
    71.     public String listParam(@RequestParam List hobby){
    72.         System.out.println(hobby);
    73.         return "YES OK!";
    74.     }
    75.  
    76.     //5.日期时间参数
    77.     //http://localhost:8080/dateParam?updateTime=2023-09-18 09:12:30
    78.     @RequestMapping("/dateParam")
    79.                             //@DateTimeFormat -> 指定时间传递的参数格式
    80.     public String dateParam(@DateTimeFormat(pattern = "yyyy-MM-dd HH:mm:ss") LocalDateTime updateTime){
    81.         System.out.println(updateTime);
    82.         return "YES OK!";
    83.     }
    84.  
    85.     //6.json参数
    86.     @RequestMapping("/jsonParam")
    87.     //@DateTimeFormat -> 指定时间传递的参数格式
    88.     public String jsonParam(@RequestBody User user){
    89.         System.out.println(user);
    90.         return "YES OK!";
    91.     }
    92.  
    93.     //7.路径参数
    94.     @RequestMapping("/path/{id}")
    95.     //@DateTimeFormat -> 指定时间传递的参数格式
    96.     public String pathParam(@PathVariable Integer id){
    97.         System.out.println(id);
    98.         return "YES OK!";
    99.     }
    100.  
    101.     //8.路径参数
    102.     //@DateTimeFormat -> 指定时间传递的参数格式
    103.     @RequestMapping("/path/{id}/{name}")
    104.     public String pathParam2(@PathVariable Integer id, @PathVariable String name){
    105.         System.out.println(id);
    106.         System.out.println(name);
    107.         return "YES OK!";
    108.     }
    109.  
    110. }

    ​

    ​


    二.响应

    ​

    1. package com.wjh.controller;
    2.  
    3. import com.wjh.pojo.Address;
    4. import org.springframework.web.bind.annotation.RequestMapping;
    5. import org.springframework.web.bind.annotation.RestController;
    6.  
    7. import java.util.ArrayList;
    8. import java.util.List;
    9.  
    10. /*
    11.     测试响应数据
    12.  */
    13. @RestController
    14. public class ResponseController {
    15.  
    16.     @RequestMapping("/hello")
    17.     public String hello(){
    18.         System.out.println("Hello word!");
    19.         return "Hello word!";
    20.     }
    21.  
    22.     @RequestMapping("/getAddress")
    23.     public Address getAddress(){
    24.         Address address = new Address();
    25.         address.setProvince("江西");
    26.         address.setCity("南昌");
    27.         System.out.println(address.getProvince() + "\n" + address.getCity());
    28.         return address;
    29.     }
    30.  
    31.     @RequestMapping("/listAddress")
    32.     public List
       listAddress(){
    33.         List
       list = new ArrayList<>();
    34.  
    35.         Address address = new Address();
    36.         address.setProvince("江西");
    37.         address.setCity("南昌");
    38.  
    39.         Address address2 = new Address();
    40.         address2.setProvince("广东");
    41.         address2.setCity("深圳");
    42.  
    43.         list.add(address);
    44.         list.add(address2);
    45.         for (Address lists: list) {
    46.             System.out.println(lists);
    47.         }
    48.         return list;
    49.     }
    50.  
    51.  
    52. }

     

    ​

    1. package com.wjh.pojo;
    2.  
    3. /**
    4.  * 统一响应结果封装类
    5.  */
    6. public class Result {
    7.     private Integer code ;//1 成功 , 0 失败
    8.     private String msg; //提示信息
    9.     private Object data; //数据 data
    10.  
    11.     public Result() {
    12.     }
    13.     public Result(Integer code, String msg, Object data) {
    14.         this.code = code;
    15.         this.msg = msg;
    16.         this.data = data;
    17.     }
    18.     public Integer getCode() {
    19.         return code;
    20.     }
    21.     public void setCode(Integer code) {
    22.         this.code = code;
    23.     }
    24.     public String getMsg() {
    25.         return msg;
    26.     }
    27.     public void setMsg(String msg) {
    28.         this.msg = msg;
    29.     }
    30.     public Object getData() {
    31.         return data;
    32.     }
    33.     public void setData(Object data) {
    34.         this.data = data;
    35.     }
    36.  
    37.     public static Result success(Object data){
    38.         return new Result(1, "success", data);
    39.     }
    40.     public static Result success(){
    41.         return new Result(1, "success", null);
    42.     }
    43.     public static Result error(String msg){
    44.         return new Result(0, msg, null);
    45.     }
    46.  
    47.     @Override
    48.     public String toString() {
    49.         return "Result{" +
    50.                 "code=" + code +
    51.                 ", msg='" + msg + '\'' +
    52.                 ", data=" + data +
    53.                 '}';
    54.     }
    55. }

    ​

     

    结果是一样的,提高了实用性

    ​

    ​

    ​

    Springboot项目的静态资源(html，css，js等前端资源)默认存放目录为：

                            classpath:/static 、 classpath:/public、 classpath:/resources

    ​

    1. package com.wjh.utils;
    2.  
    3. import org.dom4j.Document;
    4. import org.dom4j.Element;
    5. import org.dom4j.io.SAXReader;
    6. import java.io.File;
    7. import java.lang.reflect.Constructor;
    8. import java.lang.reflect.Field;
    9. import java.util.ArrayList;
    10. import java.util.List;
    11.  
    12. public class XmlParserUtils {
    13.  
    14.     public static  List parse(String file , Class targetClass)  {
    15.         ArrayList list = new ArrayList(); //封装解析出来的数据
    16.         try {
    17.             //1.获取一个解析器对象
    18.             SAXReader saxReader = new SAXReader();
    19.             //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
    20.             Document document = saxReader.read(new File(file));
    21.             //3.获取到根标签
    22.             Element rootElement = document.getRootElement();
    23.             //4.通过根标签来获取 user 标签
    24.             List elements = rootElement.elements("emp");
    25.  
    26.             //5.遍历集合,得到每一个 user 标签
    27.             for (Element element : elements) {
    28.                 //获取 name 属性
    29.                 String name = element.element("name").getText();
    30.                 //获取 age 属性
    31.                 String age = element.element("age").getText();
    32.                 //获取 image 属性
    33.                 String image = element.element("image").getText();
    34.                 //获取 gender 属性
    35.                 String gender = element.element("gender").getText();
    36.                 //获取 job 属性
    37.                 String job = element.element("job").getText();
    38.  
    39.                 //组装数据
    40.                 Constructor constructor = targetClass.getDeclaredConstructor(String.class, Integer.class, String.class, String.class, String.class);
    41.                 constructor.setAccessible(true);
    42.                 T object = constructor.newInstance(name, Integer.parseInt(age), image, gender, job);
    43.  
    44.                 list.add(object);
    45.             }
    46.         } catch (Exception e) {
    47.             e.printStackTrace();
    48.         }
    49.         return list;
    50.     }
    51.  
    52. }

    1. package com.wjh.pojo;
    2.  
    3. public class Emp {
    4.     private String name;
    5.     private Integer age;
    6.     private String image;
    7.     private String gender;
    8.     private String job;
    9.  
    10.     public Emp() {
    11.     }
    12.  
    13.     public Emp(String name, Integer age, String image, String gender, String job) {
    14.         this.name = name;
    15.         this.age = age;
    16.         this.image = image;
    17.         this.gender = gender;
    18.         this.job = job;
    19.     }
    20.  
    21.     public String getName() {
    22.         return name;
    23.     }
    24.  
    25.     public void setName(String name) {
    26.         this.name = name;
    27.     }
    28.  
    29.     public Integer getAge() {
    30.         return age;
    31.     }
    32.  
    33.     public void setAge(Integer age) {
    34.         this.age = age;
    35.     }
    36.  
    37.     public String getImage() {
    38.         return image;
    39.     }
    40.  
    41.     public void setImage(String image) {
    42.         this.image = image;
    43.     }
    44.  
    45.     public String getGender() {
    46.         return gender;
    47.     }
    48.  
    49.     public void setGender(String gender) {
    50.         this.gender = gender;
    51.     }
    52.  
    53.     public String getJob() {
    54.         return job;
    55.     }
    56.  
    57.     public void setJob(String job) {
    58.         this.job = job;
    59.     }
    60.  
    61.     @Override
    62.     public String toString() {
    63.         return "Emp{" +
    64.                 "name='" + name + '\'' +
    65.                 ", age=" + age +
    66.                 ", image='" + image + '\'' +
    67.                 ", gender='" + gender + '\'' +
    68.                 ", job='" + job + '\'' +
    69.                 '}';
    70.     }
    71. }

    1. package com.wjh.controller;
    2.  
    3. import com.wjh.pojo.Emp;
    4. import com.wjh.pojo.Result;
    5. import com.wjh.utils.XmlParserUtils;
    6. import org.springframework.web.bind.annotation.RequestMapping;
    7. import org.springframework.web.bind.annotation.RestController;
    8.  
    9. import java.util.List;
    10.  
    11. @RestController
    12. public class EmoController {
    13.  
    14.     @RequestMapping("/listEmp")
    15.     public Result list(){
    16.         //1.加载并解析emp.xml文件
    17.  
    18.         //String file = "D:\\JavaWeb2023\\java_web_project\\springboot-web-req-resp\\src\\main\\resources\\emp.xml";
    19.         String file = this.getClass().getClassLoader().getResource("emp.xml").getFile();
    20.         System.out.println(file);
    21.         List empList =  XmlParserUtils.parse(file, Emp.class);
    22.  
    23.         //2.对数据进行转换处理 -gender, job
    24.         empList.stream().forEach(emp -> {
    25.             //处理gander 1: 男, 2: 女
    26.             String gander = emp.getGender();
    27.             if("1".equals(gander)){
    28.                 emp.setGender("男");
    29.             }else if("2".equals(gander)){
    30.                 emp.setGender("女");
    31.             }
    32.  
    33.             //处理job - 1:讲师, 2:班主任, 3:就业指导
    34.             String job = emp.getJob();
    35.             if("1".equals(job)){
    36.                 emp.setJob("讲师");
    37.             }else if("2".equals(job)){
    38.                 emp.setJob("班主任");
    39.             }else if("3".equals(job)){
    40.                 emp.setJob("就业指导");
    41.             }
    42.  
    43.         });
    44.  
    45.  
    46.         //3.响应数据
    47.         return Result.success(empList);
    48.     }
    49. }

     

     

    ​


    三.分层解耦

    1.三层架构

    ​

    ​

    ​

    ​

     

    1. package com.wjh.controller;
    2.  
    3. import com.wjh.pojo.Emp;
    4. import com.wjh.pojo.Result;
    5. import com.wjh.service.EmpService;
    6. import com.wjh.service.impl.EmpServiceA;
    7. import com.wjh.utils.XmlParserUtils;
    8. import org.springframework.web.bind.annotation.RequestMapping;
    9. import org.springframework.web.bind.annotation.RestController;
    10.  
    11. import java.util.List;
    12.  
    13. @RestController
    14. public class EmoController {
    15.     private EmpService empService = new EmpServiceA();
    16.  
    17.     @RequestMapping("/listEmp")
    18.     public Result list() {
    19.         //1.调用service,获取数据
    20.         List empList = empService.listEmp();
    21.  
    22.         //3.响应数据
    23.         return Result.success(empList);
    24.     }
    25. }
    26.  
    27.  
    28.  
    29.  
    30. //    //1.加载并解析emp.xml文件
    31. //
    32. //    //String file = "D:\\JavaWeb2023\\java_web_project\\springboot-web-req-resp\\src\\main\\resources\\emp.xml";
    33. //    String file = this.getClass().getClassLoader().getResource("emp.xml").getFile();
    34. //        System.out.println(file);
    35. //    List empList =  XmlParserUtils.parse(file, Emp.class);
    36. //
    37. //    //2.对数据进行转换处理 -gender, job
    38. //        empList.stream().forEach(emp -> {
    39. //        //处理gander 1: 男, 2: 女
    40. //        String gander = emp.getGender();
    41. //        if("1".equals(gander)){
    42. //            emp.setGender("男");
    43. //        }else if("2".equals(gander)){
    44. //            emp.setGender("女");
    45. //        }
    46. //
    47. //        //处理job - 1:讲师, 2:班主任, 3:就业指导
    48. //        String job = emp.getJob();
    49. //        if("1".equals(job)){
    50. //            emp.setJob("讲师");
    51. //        }else if("2".equals(job)){
    52. //            emp.setJob("班主任");
    53. //        }else if("3".equals(job)){
    54. //            emp.setJob("就业指导");
    55. //        }
    56. //
    57. //    });
    58.  

    1. package com.wjh.Dao.impl;
    2.  
    3. import com.wjh.Dao.EmpDao;
    4. import com.wjh.pojo.Emp;
    5. import com.wjh.utils.XmlParserUtils;
    6.  
    7. import java.util.List;
    8.  
    9. public class EmoDaoA implements EmpDao {
    10.  
    11.     @Override
    12.     public List listEmp() {
    13.         String file = this.getClass().getClassLoader().getResource("emp.xml").getFile();
    14.         System.out.println(file);
    15.         List empList =  XmlParserUtils.parse(file, Emp.class);
    16.         return empList;
    17.     }
    18. }

     

    1. package com.wjh.Dao;
    2.  
    3. import com.wjh.pojo.Emp;
    4.  
    5. import java.util.List;
    6.  
    7. public interface EmpDao {
    8.     //获取员工列表数据
    9.     public List listEmp();
    10. }

    1. package com.wjh.pojo;
    2.  
    3. public class Emp {
    4.     private String name;
    5.     private Integer age;
    6.     private String image;
    7.     private String gender;
    8.     private String job;
    9.  
    10.     public Emp() {
    11.     }
    12.  
    13.     public Emp(String name, Integer age, String image, String gender, String job) {
    14.         this.name = name;
    15.         this.age = age;
    16.         this.image = image;
    17.         this.gender = gender;
    18.         this.job = job;
    19.     }
    20.  
    21.     public String getName() {
    22.         return name;
    23.     }
    24.  
    25.     public void setName(String name) {
    26.         this.name = name;
    27.     }
    28.  
    29.     public Integer getAge() {
    30.         return age;
    31.     }
    32.  
    33.     public void setAge(Integer age) {
    34.         this.age = age;
    35.     }
    36.  
    37.     public String getImage() {
    38.         return image;
    39.     }
    40.  
    41.     public void setImage(String image) {
    42.         this.image = image;
    43.     }
    44.  
    45.     public String getGender() {
    46.         return gender;
    47.     }
    48.  
    49.     public void setGender(String gender) {
    50.         this.gender = gender;
    51.     }
    52.  
    53.     public String getJob() {
    54.         return job;
    55.     }
    56.  
    57.     public void setJob(String job) {
    58.         this.job = job;
    59.     }
    60.  
    61.     @Override
    62.     public String toString() {
    63.         return "Emp{" +
    64.                 "name='" + name + '\'' +
    65.                 ", age=" + age +
    66.                 ", image='" + image + '\'' +
    67.                 ", gender='" + gender + '\'' +
    68.                 ", job='" + job + '\'' +
    69.                 '}';
    70.     }
    71. }

    1. package com.wjh.service.impl;
    2.  
    3. import com.wjh.Dao.EmpDao;
    4. import com.wjh.Dao.impl.EmoDaoA;
    5. import com.wjh.pojo.Emp;
    6. import com.wjh.service.EmpService;
    7.  
    8. import java.util.List;
    9.  
    10. public class EmpServiceA implements EmpService {
    11.     private EmpDao empDao = new EmoDaoA();
    12.     @Override
    13.     public List listEmp() {
    14.         //1.调用dao,获取数据
    15.         List empList = empDao.listEmp();
    16.  
    17.         //2.对数据进行转换处理 -gender, job
    18.         empList.stream().forEach(emp -> {
    19.             //处理gander 1: 男, 2: 女
    20.             String gander = emp.getGender();
    21.             if("1".equals(gander)){
    22.                 emp.setGender("男");
    23.             }else if("2".equals(gander)){
    24.                 emp.setGender("女");
    25.             }
    26.  
    27.             //处理job - 1:讲师, 2:班主任, 3:就业指导
    28.             String job = emp.getJob();
    29.             if("1".equals(job)){
    30.                 emp.setJob("讲师");
    31.             }else if("2".equals(job)){
    32.                 emp.setJob("班主任");
    33.             }else if("3".equals(job)){
    34.                 emp.setJob("就业指导");
    35.             }
    36.         });
    37.         return empList;
    38.     }
    39. }

     

    1. package com.wjh.service;
    2.  
    3. import com.wjh.pojo.Emp;
    4.  
    5. import java.util.List;
    6.  
    7. public interface EmpService {
    8.     //获取员工列表
    9.     public List listEmp();
    10.  
    11. }


    2.分层解耦

    ​

    ​

    ​

    ​

    控制反转：

            Inversion Of Control，简称IOC。对象的创建控制权由程序自身转移到外部（容器），这种思想称为控制反转。


    依赖注入：

            Dependency Injection，简称DI。容器为应用程序提供运行时，所依赖的资源，称之为依赖注入。


    Bean对象：

            IOC容器中创建、管理的对象，称之为bean。


    3.IOC & DI入门

    ​

    ​

     

     @Component     //将当前类交给IOC容器管理,成为IOC容器中的bean

    @Autowired         //运行时,IOC容器会提供该类型的bean对象,并复制给改变量 - 依赖注入

     

    ​

     

     

    ​

     

    4.IOC详解

    ​

    ​

     

    ​

    5.DI详解

    ​

    @Primary        -->         在又多个相同bean情况下,想用的实现方法上加这个注解


    @Qualifier       -->         @Qualifier("A") 或者@Qualifier ("B")


    @Resource     -->         不属于springboot,属于JDK当中的,加在private EmpDao empDao 上

    ​

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  • 原文地址：https://blog.csdn.net/wangjh11234/article/details/132921790