Java如何使用xml做数据库

1.引用包 maven

<!--xml做数据库工具-->
<dependency>
    <groupId>dom4j</groupId>
    <artifactId>dom4j</artifactId>
    <version>1.6.1</version>
</dependency>
<dependency>
    <groupId>jaxen</groupId>
    <artifactId>jaxen</artifactId>
    <version>1.1.1</version>
</dependency>
<!-- 阿里的，类转map，map 转类-->
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>fastjson</artifactId>
    <version>1.2.54</version>
</dependency>

2.数据库的xml文件

放到springboot 项目中的文件 taglibrary/src/main/resources/xmldatabase/userxml.xml

<?xml version="1.0" encoding="UTF-8"?>
<RECORDS>
<RECORD>
<id>1</id>
<username>用户名</username>
<deptId>部门</deptId>
<sex>男</sex>
<iconid>头像id</iconid>
<city>北京</city>
<password>password</password>
<onlinestate>状态</onlinestate>
<lastlogintime>最后登录时间</lastlogintime>
<registertime>时间</registertime>
</RECORD>
<RECORD>
<id>2021060715375511</id>
<username>2</username>
<deptId>1</deptId>
<sex>2</sex>
<iconid>2</iconid>
<city>1</city>
<password>2</password>
<onlinestate>2</onlinestate>
<lastlogintime>2</lastlogintime>
<registertime>2</registertime>
</RECORD>
</RECORDS>

3 application 配置xml地址和名称

xmldatabase.path = D:/ideaWorkspace/work20210607biaoqianku/taglibrary/src/main/resources/xmldatabase/
xmldatabase.userxml = userxml.xml

3 代码

UserxmlDao.java

package com.taglibrary.platform.userxml;

import com.alibaba.fastjson.JSON;
import com.taglibrary.commonbase.BaseDao;
import org.dom4j.Attribute;
import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;
import org.dom4j.io.XMLWriter;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;

/**
 *
 *
 * @author wjk
 * @date  2021/06/09
 */

@Service
public class UserxmlDao extends BaseDao {

    @Value("${xmldatabase.path}")
    private String xmldatabasePath;
    @Value("${xmldatabase.userxml}")
    private String tableName;

    /**
     * 获取全部数据
     * @return List<Userxml>
     */
    public List<Userxml> getAll() {
        List<Userxml> list = new ArrayList<Userxml>();
        //定义一个reader和HashMap，HashMap是用来返回我们要查询的这个用户的信息的
        SAXReader reader = new SAXReader();
        try {

            //得到user.xml的这个doc
            Document doc = reader.read(new File(xmldatabasePath+tableName));
            //得到所有用户的一个集合userList
            List<Element> userList = doc.selectNodes("//RECORDS/RECORD");
            //得到迭代器，
            Iterator<Element> iter = userList.iterator();

            while (iter.hasNext()) {
                HashMap<String, String> map = new HashMap<String, String>();
                //得到每一个user元素，进行判断
                Element e = iter.next();
                //如果这个user的ID和我们查询的ID一致，则将其所有的信息放入到map当中
                //得到这个user的所有子元素
                List<Element> childElements = e.elements();
                //得到所有子元素的迭代器
                Iterator<Element> childIter = childElements.iterator();
                //如果还有子元素，则
                while (childIter.hasNext()) {
                    //得到子元素，将其信息放入到map当中
                    Element childElement = childIter.next();
                    map.put(childElement.getQName().getName(), childElement.getText());
                }
                Userxml userxml = JSON.parseObject(JSON.toJSONString(map), Userxml.class);
                list.add(userxml);
            }
        } catch (Exception e) {
            e.printStackTrace();
            logger.error(e.toString());
        }
        return list;
    }
    /**
    * 查询
    * @param Id
    * @return Userxml
    */
    public Userxml getOne(Long Id){
        Userxml userxml = new Userxml();
        List<Userxml> list =  getAll();
            for(int i = 0; i<list.size();i++){
                Userxml userxmltmp = list.get(i);
                if(userxmltmp.getId().toString().equals(Id.toString())){
                userxml = userxmltmp;
                break;
            }
        }
        return userxml;
     };

    /**
    *  增加
    * @param userxml
    * @return Userxml
    */
    public Userxml insert(Userxml userxml){
        try{
            //读取文件
            SAXReader saxReader = new SAXReader();
            Document doc = saxReader.read(new File(xmldatabasePath+tableName));
            //得到跟结点root
            Element root = doc.getRootElement();
            //往根节点添加user元素
            Element element = root.addElement("RECORD");
            //设置element的ID
            element.addAttribute("id", userxml.getId().toString());

            //往user添加各种子元素和设置值
            Element Id = element.addElement("id");
            Id.setText(userxml.getId().toString());
            Element Username = element.addElement("username");
            Username.setText(userxml.getUsername().toString());
            Element Deptid = element.addElement("deptid");
            Deptid.setText(userxml.getDeptid().toString());
            Element Sex = element.addElement("sex");
            Sex.setText(userxml.getSex().toString());
            Element Iconid = element.addElement("iconid");
            Iconid.setText(userxml.getIconid().toString());
            Element City = element.addElement("city");
            City.setText(userxml.getCity().toString());
            Element Password = element.addElement("password");
            Password.setText(userxml.getPassword().toString());
            Element Onlinestate = element.addElement("onlinestate");
            Onlinestate.setText(userxml.getOnlinestate().toString());
            Element Lastlogintime = element.addElement("lastlogintime");
            Lastlogintime.setText(userxml.getLastlogintime().toString());
            Element Registertime = element.addElement("registertime");
            Registertime.setText(userxml.getRegistertime().toString());

            //添加元素结束后往新的文件重新写入doc数据
            XMLWriter output = new XMLWriter(new FileWriter( new File(xmldatabasePath+tableName) ));
            output.write(doc);
            //关闭输出流
            output.close();

        }

        catch(DocumentException e){
            e.printStackTrace();
        }

        catch(IOException e){
            e.printStackTrace();
        }
        return userxml;
    }
    /**
    * 删除
    * @param Id
    * @return Userxml
    */
    public Userxml delete(Long Id){
        Userxml userxml = new Userxml();
        SAXReader reader = new SAXReader();
        try {
            //得到user.xml的Document
            Document doc = reader.read(new File(xmldatabasePath+tableName));
            //得到跟结点
            Element root = doc.getRootElement();
            //得到根节点下的所有user集合
            List<Element> userList = doc.selectNodes("//RECORDS/RECORD");
            //得到迭代器
            Iterator<Element> iter = userList.iterator();
            while(iter.hasNext()){
                HashMap<String, String> map = new HashMap<String, String>();
                //得到user元素
                Element e = iter.next();
                //得到这个user的所有子元素
                List<Element> childElements = e.elements();
                //得到所有子元素的迭代器
                Iterator<Element> childIter = childElements.iterator();
                    //如果还有子元素，则
                    while (childIter.hasNext()) {
                    //得到子元素，将其信息放入到map当中
                    Element childElement = childIter.next();
                    map.put(childElement.getQName().getName(), childElement.getText());
                }
                Userxml userxmlTmp = JSON.parseObject(JSON.toJSONString(map), Userxml.class);
                if(userxmlTmp.getId() == Id){
                    root.remove(e);
                    userxml = userxmlTmp;
                }
            }
            //得到XML的输出流
            XMLWriter output;
            try {
                output = new XMLWriter(new FileWriter( new File(xmldatabasePath+tableName) ));
                //将内存中的doc写入到新文件当中
                output.write(doc);
                //关闭输出流
                output.close();
             } catch (IOException e) {
                e.printStackTrace();
            }
        } catch (DocumentException e) {
            e.printStackTrace();
        }
        return userxml;
    }

    /**
    *  修改
    * @param userxml
    * @return userxml
    */
    public Userxml update(Userxml userxml){
        try {
            //得到user.xml文件，将其读取到doc当中
            SAXReader reader = new SAXReader();
            Document doc = reader.read(new File(xmldatabasePath+tableName));
            //得到跟结点root
            Element root = doc.getRootElement();
            //得到根节点TUser下的所有用户，将其存放到userList当中
            List<Element> userList = doc.selectNodes("//RECORDS/RECORD");
            //得到可以访问所有用户的迭代器Iterator
            Iterator<Element> iter = userList.iterator();
            //如果迭代器还有下一个，则取出来
            while(iter.hasNext()){
                HashMap<String, String> map = new HashMap<String, String>();

                //得到user元素
                Element e = iter.next();
                //得到这个user的所有子元素
                List<Element> childElements = e.elements();
                //得到所有子元素的迭代器
                Iterator<Element> childIter = childElements.iterator();
                //如果还有子元素，则
                while (childIter.hasNext()) {
                    //得到子元素，将其信息放入到map当中
                    Element childElement = childIter.next();
                    map.put(childElement.getQName().getName(), childElement.getText());
                }
                Userxml userxmlTmp = JSON.parseObject(JSON.toJSONString(map), Userxml.class);
                if(userxml.getId() == userxmlTmp.getId()){
                    Class cls = userxml.getClass();
                    Field[] fields = cls.getDeclaredFields();
                    for(int i=0; i<fields.length; i++){
                        Field f = fields[i];
                        f.setAccessible(true);
                        Element childElement = e.element(f.getName());
                        try {
                             childElement.setText(f.get(userxml).toString());
                        } catch (IllegalAccessException iae) {
                                                iae.printStackTrace();
                        }
                    }
                }
            }
            //得到XML的输出流
            XMLWriter output;
            try {
                output = new XMLWriter(new FileWriter( new File(xmldatabasePath+tableName) ));
                //将内存中的doc写入到新文件当中
                output.write(doc);
                //关闭输出流
                output.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        } catch (DocumentException e) {
            e.printStackTrace();
        }
        return userxml;
    }

}

UserxmlController.java

package com.taglibrary.platform.userxml;

import java.util.List;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.mybatis.logging.LoggerFactory;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.*;
import org.springframework.context.annotation.Scope;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import javax.annotation.Resource;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.PrintWriter;
import java.util.List;

import com.taglibrary.commonbase.BaseController;
import com.taglibrary.util.ReturnDataJson;

import com.taglibrary.platform.userxml.Userxml;
import com.taglibrary.platform.userxml.UserxmlService;
/**
 *
 *
 * @author wjk
 * @date  2021/06/09
 */
@Controller
@Scope("request")
@RequestMapping("/userxml")
@Api(value = "", tags = {""})
public class UserxmlController extends BaseController {

    @Resource
    private UserxmlService service;

    @Resource
    private UserxmlDao dao;

    /**
    * 查询（获取全部）
    */
    @RequestMapping(value = "/getAll",method=RequestMethod.POST)
    @ResponseBody
    @ApiOperation(value = "查询（获取全部）")
    public ReturnDataJson getall() {
        ReturnDataJson res;
        try {
            List<Userxml> list = this.dao.getAll();
            res = this.responseReturnDataJson(true,"成功",list,Long.valueOf(list.size()));
        } catch (Exception e) {
            logger.error(e.getMessage(), e);
            res = this.responseReturnDataJson(false,"失败");
        }
        return res;
    }


    /**
    * 查询（根据id）
    */
    @RequestMapping(value = "/detail",method=RequestMethod.POST)
    @ResponseBody
    @ApiOperation(value = "查询（根据id）")
    public ReturnDataJson detail(@RequestBody Userxml userxml) {
        ReturnDataJson res;
        try {
            Userxml olduserxml= this.dao.getOne(userxml.getId());
            if(olduserxml.getId() == null){
                res = this.responseReturnDataJson(false,"失败","未查询到数据（id="+userxml.getId().toString()+"）");
            } else{
                 res = this.responseReturnDataJson(true,"成功");
            }
        } catch (Exception e) {
            logger.error(e.getMessage(), e);
            res = this.responseReturnDataJson(false,"失败");
        }
        return res;
  }
    /**
     * 增加
     **/
    @RequestMapping(value = "/add",method=RequestMethod.POST)
    @ResponseBody
    @ApiOperation(value = "增加")
    public ReturnDataJson add(@RequestBody Userxml userxml) {
        ReturnDataJson res;
        try {
            Userxml olduserxml= this.dao.getOne(userxml.getId());
            if(olduserxml.getId() == null){
                Userxml newuserxml= this.dao.insert(userxml);
                res = this.responseReturnDataJson(true,"成功",newuserxml);
            } else{
                res = this.responseReturnDataJson(false,"失败","已有数据（id="+olduserxml.getId().toString()+"）");
            }
        } catch (Exception e) {
            logger.error(e.getMessage(), e);
            res = this.responseReturnDataJson(false,"失败");
        }
        return res;
    }

    /**
     * 修改
     **/
    @RequestMapping(value = "/update",method=RequestMethod.POST)
    @ResponseBody
    @ApiOperation(value = "修改（根据id）")
    public ReturnDataJson update(@RequestBody Userxml userxml) {
        ReturnDataJson res;
        try {
            Userxml olduserxml= this.dao.getOne(userxml.getId());
            if(olduserxml.getId() == null){
                res = this.responseReturnDataJson(false,"失败","未查询到数据（id="+userxml.getId().toString()+"）");
            } else{
                Userxml newuserxml= this.dao.update(userxml);
                res = this.responseReturnDataJson(true,"成功",newuserxml);
            }
        } catch (Exception e) {
            logger.error(e.getMessage(), e);
            res = this.responseReturnDataJson(false,"失败");
        }
        return res;
    }

    /**
     * 删除（根据id）
     **/
    @RequestMapping(value = "/delete",method=RequestMethod.POST)
    @ResponseBody
    @ApiOperation(value = "删除（根据id）")
    public ReturnDataJson delete(@RequestBody Userxml userxml) {
        ReturnDataJson res;
        try {
            Userxml olduserxml= this.dao.getOne(userxml.getId());
            if(olduserxml.getId() == null){
                res = this.responseReturnDataJson(false,"失败","未查询到数据（id="+userxml.getId().toString()+"）");
            } else{
                Userxml newuserxml= this.dao.delete(userxml.getId());
                res = this.responseReturnDataJson(true,"成功");
            }
        } catch (Exception e) {
            logger.error(e.getMessage(), e);
            res = this.responseReturnDataJson(false,"失败");
        }
        return res;
    }

}