简单的员工管理-spring初步应用

重铸化工荣光我辈义不容辞
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本项目为黑马javaweb学习笔记 该项目采取了springboot框架，是该框架的初步应用。 数据存储在xml文件之中，并没有使用数据库。

  • 该项目使用技术
  1. springboot进行请求响应以及数据处理封装
  2. dom4j负责处理xml文件中存储的数据
  3. 三层解耦
  4. IOC（控制反转）和DI（依赖注入）
  • 首先是项目目录结构

image.png 该项目为一个标准的maven项目结构

  1. controller负责响应请求
  2. dao负责处理数据
  3. server负责业务逻辑处理
  4. pojo负责存储项目需要用到的公共类
  • dao代码及解析
  • 首先是负责解析xml文件的代码
import org.dom4j.Document;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;
import springruest.pojo.Emp;

import java.io.File;
import java.util.ArrayList;
import java.util.List;

public class XmlParse {
    public static List<Emp> parse(String file){
        ArrayList<Emp> res = new ArrayList<>();
        try{
            File fr = new File(file);
            SAXReader saxReader = new SAXReader();
            Document document = saxReader.read(fr);
            Element root = document.getRootElement();
            List<Element> rootElement = root.elements();
            for(Element e:rootElement){
                Emp emp = new Emp();
                emp.setName(e.element("name").getText());
                emp.setAge(Integer.parseInt(e.element("age").getText()));
                emp.setImage(e.element("image").getText());
                emp.setGender(e.element("gender").getText());
                emp.setJob(e.elementText("job"));
                res.add(emp);
            }
        }catch (Exception e){
            System.out.println("error");
        }
        return res;
    }

    public static void main(String[] args) {
        XmlParse xmlParse = new XmlParse();
        List<Emp> res = xmlParse.parse("resources\emp.xml");
        for (Emp e : res){
            System.out.println(e);
        }
    }

}

xml具体文档如下

<?xml version="1.0" encoding="UTF-8" ?>
<emps>
    <emp>
        <name>j</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>b</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>q</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>z</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>

接下来是EmpDao的代码，实际上就是解析XML的代码+一个进行将该类的对象注入容器之中的代码

import org.dom4j.Document;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;
import org.springframework.stereotype.Repository;
import springruest.pojo.Emp;

import java.io.File;
import java.util.ArrayList;
import java.util.List;
//@Component将该类的对象注入容器之中
@Repository(value = "Ea")
//@Repository(value = "Ea")可以通过value进行指定对象名，不指定默认类名首字母小写
public class EmpDao {
    public static List<Emp> parse(String file){
        ArrayList<Emp> res = new ArrayList<>();
        try{
            File fr = new File(file);
            SAXReader saxReader = new SAXReader();
            Document document = saxReader.read(fr);
            Element root = document.getRootElement();
            List<Element> rootElement = root.elements();
            for(Element e:rootElement){
                Emp emp = new Emp();
                emp.setName(e.element("name").getText());
                emp.setAge(Integer.parseInt(e.element("age").getText()));
                emp.setImage(e.element("image").getText());
                emp.setGender(e.element("gender").getText());
                emp.setJob(e.elementText("job"));
                res.add(emp);
            }
        }catch (Exception e){
            System.out.println("error");
        }
        return res;
    }

    public static void main(String[] args) {
        XmlParse xmlParse = new XmlParse();
        List<Emp> res = xmlParse.parse("resources\emp.xml");
        for (Emp e : res){
            System.out.println(e);
        }
    }
}

Resulet负责统一相应格式，其中的data会在响应时自动封装为JSON格式的数据

public class Result {
    private Integer code ;//1 成功 , 0 失败
    private String msg; //提示信息
    private Object data; //数据 date

    public 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);
    }
}

User只是简单的封装员工对象的实体类，需要注意的是，数据库中的变量常用_而实体类中场用驼峰命名法，变量名不一致无法进行正确的数据封装，需要在配置中开启自动转换

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;
        }

        @Override
        public String toString() {
            return "User{" +
                    "name='" + name + ''' +
                    ", age=" + age +
                    ", address=" + address +
                    '}';
        }
    }

RequestExample展示了Spring对于不同类型的数据，对应的处理方法

package springruest.RequestExample;

import org.springframework.format.annotation.DateTimeFormat;
import org.springframework.web.bind.annotation.*;
import java.time.LocalDateTime;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

class address{
    private String province = "";
    private String city = "";

    public address() {
    }

    @Override
    public String toString() {
        return "address{" +
                "province='" + province + ''' +
                ", city='" + 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;
    }
}
class User{
    private String name ="";
    private int age = 0;
    private address addr =null;
    String[] hobby;
    List<String> classGrid = new ArrayList<>();
    public User() {
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public address getAddr() {
        return addr;
    }

    public void setAddr(address addr) {
        this.addr = addr;
    }

    public void setHobby(String[] hobby) {
        this.hobby = hobby;
    }

    public void setClassGrid(List<String> classGrid) {
        this.classGrid = classGrid;
    }

    @Override
    public String toString() {
        return "User{" +
                "name='" + name + ''' +
                ", age=" + age +
                ", addr=" + addr +
                ", hobby=" + Arrays.toString(hobby) +
                ", classGrid=" + classGrid +
                '}';
    }
}
class nowDate{
    private LocalDateTime localDateTime;

    public LocalDateTime getLocalDateTime() {
        return localDateTime;
    }

    public void setLocalDateTime(LocalDateTime localDateTime) {
        this.localDateTime = localDateTime;
    }

    @Override
    public String toString() {
        return "nowDate{" +
                "localDateTime=" + localDateTime +
                '}';
    }
}

@RestController
public class RequestExample {
    //最原始的请求方法，解析复杂，现在已经废弃
//    @RequestMapping("/simpleParam")
//    public String simpleParam(HttpServletRequest request){
//        String name = request.getParameter("name");
//        String age = request.getParameter("age");
//        System.out.println(name+age);
//        return "ok";
//    }
    @RequestMapping("/simpleParam")
    //Spring会自动进行类型转换，无论是get还是post只需要请求名一致即可
    //或者变量名不一致但是可以进行参数映射,且使用@RequestParam以后，该参数必须传递required默认为ture
    public String simpleParam(@RequestParam(name = "name",required = false) String uname, Integer age){
        System.out.println(uname+age);
        return "ok";
    }
    //spring默认是对数组进行赋值，所以要使用@RequestParam进行转换,不转换会报错
    //http://localhost:8080/simpleList?list=1&list=2
    @RequestMapping("/simpleList")
    public List<String> simpleList(@RequestParam List<String> list){
        System.out.println(list);
        return list;
    }

    @RequestMapping("/complexClass/{id}/{name}")
    //json格式使用类对象来进行接受，且key和变量名必须一致，json只能使用post
    //http://localhost:8080/complexClass?classGrid=1&classGrid=2&classGrid=3&name=tom&age=12&addr.province=jilin&addr.city=baishan&hobby=a&hobby=b
    //但是当List位于类中时，无需转换
    //想要接受json格式的数据，必须用@RequestBody
//    {
//        "name":"tom",
//            "age":10,
//            "addr":{
//        "province":"jilin",
//                "city":"baishan"
//    },
//        "hobby":["1","2","3"],
//        "classGrid":["a","b"]
//    }
    //路径参数可以有多个，必须使用@PathVariable，且参数名必须要上下一致
    public String complexClass(@RequestBody User user, @PathVariable Integer id,@PathVariable String name){
        System.out.println(user);
        System.out.println(user.getAddr().toString());
        return String.valueOf(id)+name;
    }
    @RequestMapping("/time")
    public LocalDateTime time(@DateTimeFormat(pattern = "yyyy-MM-dd HH-mm-ss") LocalDateTime localDateTime){
        System.out.println(localDateTime);
        return localDateTime;
    }
}

server包负责业务逻辑处理，需要把dao层的原始数据处理成前端需要的格式

  • 首先是定义一个接口
import springruest.pojo.Emp;

import java.util.List;

public interface EmpServer {
     public List<Emp> Emp();
}

imo包下为该接口的两个具体的实现类

image.png

image.png

image.png

  1. EmpServerA
package springruest.server.imo;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Primary;
import org.springframework.stereotype.Service;
import springruest.pojo.Emp;
import springruest.server.EmpServer;
import springruest.dao.EmpDao;
import java.util.List;
@Primary
//优先生效
@Service
//当存在两个同样目的服务时，可以通过@Component选择将哪个对象注入容器
//@Component存在三个衍生注解@Controller，@Service，@Repository分别用于控制器，业务类，数据访问的Dao层中
//@Repository与mybatis整合，用的少
//@Controller与@ResponseBody整合成@RestController了
public class EmpServerA implements EmpServer {
    @Autowired
    private EmpDao empDao;
    @Override
    public List<Emp> Emp() {
        List<Emp> EmpList = EmpDao.parse("resources\emp.xml");

        for(Emp e: EmpList){
            if(e.getGender().equals("1") ){
                e.setGender("男");
            }else{
                e.setGender("女");
            }
            if(e.getJob().equals("1")){
                e.setJob("讲师");
            }else if(e.getJob().equals("2")){
                e.setJob("班主任");
            }else{
                e.setJob("就业指导");
            }
        }
        System.out.println(EmpList);
        return EmpList;
    }

    public static void main(String[] args) {
        var emp = new EmpServerA();
        System.out.println(emp.Emp());
    }
}
  1. EmpServerB
package springruest.server.imo;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import springruest.pojo.Emp;
import springruest.server.EmpServer;
import springruest.dao.EmpDao;
import java.util.List;
@Component
public class EmpServerB implements EmpServer {
    @Autowired
    private EmpDao empDao;
    @Override
    public List<Emp> Emp() {
        List<Emp> EmpList = EmpDao.parse("resources\emp.xml");

        for(Emp e: EmpList){
            if(e.getGender().equals("1") ){
                e.setGender("man");
            }else{
                e.setGender("wowan");
            }
            if(e.getJob().equals("1")){
                e.setJob("讲师");
            }else if(e.getJob().equals("2")){
                e.setJob("班主任");
            }else{
                e.setJob("就业指导");
            }
        }
        System.out.println(EmpList);
        return EmpList;
    }

    public static void main(String[] args) {
        var emp = new EmpServerA();
        System.out.println(emp.Emp());
    }
}
  • EmpControllor 由于@Autowired默认是按照类型注入，所以如果没有额外指定优先级，那么将按照字母顺序去查找对应接口的实现类，就比如下列代码中的
@Autowired
private EmpServer empServer ;

将会默认该实现类为empServerA

package springruest.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import springruest.pojo.Result;
import springruest.server.EmpServer;
@RestController
public class EmpControllor {
    //@Resource可以指定注入bean的对象的名字
//    @Resource(name = "empServerB")//优先度最高
    //@Resource由JDk提供而@Autowired由spring提供
    //@Resource默认由名称提供而@Autowired默认由类型提供
    //可以利用该注解将容器之中的对象交给变量
    //@Autowired默认是根据类进行注入
    //同类型只允许一个注入
    //可以通过@Primary,@Qualifier,@Resource解决
    //@Primary指定优先选择的类
    @Autowired
    private EmpServer empServer ;
    @RequestMapping("/EmpList")
    public Result EmpList(){
        var res = new Result().success(empServer.Emp());
        return res;
    }
}

最后是pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.7.4</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>SpringRuest</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>SpringRuest</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>11</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>dom4j</groupId>
            <artifactId>dom4j</artifactId>
            <version>1.6.1</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <version>2.7.4</version>
            </plugin>
        </plugins>
    </build>

</project>
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