模仿mongodb采用xml+json实现小型数据库
?http://zhangdaiscott.github.io/mini-mogodb
package org.jeecgframework;import java.io.FileInputStream;import java.io.FileOutputStream;import java.io.IOException;import java.util.ArrayList;import java.util.HashMap;import java.util.List;import java.util.Map;import java.util.UUID;import org.jdom.Document;import org.jdom.Element;import org.jdom.JDOMException;import org.jdom.input.SAXBuilder;import org.jdom.output.XMLOutputter;import com.google.gson.Gson;public class MiniMogodb {private static final String _uuid = "_uuid";/** * 获取表的全部数据 *? * @param path * @param tablename * @return * @throws Exception */public List<Map> loadTableDatas(String path, String tablename) throws Exception {Gson gson = new Gson();FileInputStream file = new FileInputStream(path);SAXBuilder saxBuilder = new SAXBuilder();Document document = saxBuilder.build(file);Element root = document.getRootElement();List<Map> l = new ArrayList();List<Element> list = root.getChildren();for (Element x : list) {if (x.getAttributeValue("name").equals(tablename)) {List<Element> al = x.getChildren();for (Element s : al) {String data = s.getText();if (data == null) {break;}Map mp = gson.fromJson(data, Map.class);l.add(mp);}}}return l;}/** * 表插入数据 *? * @param path * @param tablename * @param po * @return * @throws JDOMException * @throws IOException */public boolean addData(String path, String tablename, Object po)throws JDOMException, IOException {Gson gson = new Gson();boolean flag = false;FileInputStream file = new FileInputStream(path);SAXBuilder saxBuilder = new SAXBuilder();Document document = saxBuilder.build(file);Element root = document.getRootElement();List<Element> list = root.getChildren();for (Element x : list) {if (x.getAttributeValue("name").equals(tablename)) {Map base = new HashMap();base.put(_uuid, UUID.randomUUID().toString());Element data = new Element("data");String json = gson.toJson(po);Map mp = gson.fromJson(json, Map.class);base.putAll(mp);data.addContent(gson.toJson(base));x.addContent(data);}}XMLOutputter out = new XMLOutputter();out.output(document, new FileOutputStream(path));flag = true;System.out.println("----------insert --- data --- success----------------------");return flag;}/** * 表修改数据 *? * @param path * @param tablename * @param po * @throws JDOMException * @throws IOException */public void updateData(String path, String tablename, Object po)throws JDOMException, IOException {FileInputStream file = new FileInputStream(path);SAXBuilder saxBuilder = new SAXBuilder();Document document = saxBuilder.build(file);Element root = document.getRootElement();Gson gson = new Gson();List<Element> list = root.getChildren();for (Element x : list) {if (x.getAttributeValue("name").equals(tablename)) {List<Element> al = x.getChildren();for (Element s : al) {// 如果定位Data[通过UUID唯一标示]Map mp = gson.fromJson(s.getText(), Map.class);Map newmp = gson.fromJson(gson.toJson(po), Map.class);if (mp.get(_uuid).equals(newmp.get(_uuid))) {mp.putAll(newmp);Element data = new Element("data");data.setText(gson.toJson(mp));x.removeContent(s);x.addContent(data);break;}}}}XMLOutputter out = new XMLOutputter();out.output(document, new FileOutputStream(path));System.out.println("----------update --- data --- success----------------------");}/** * 表删除数据 *? * @param path * @param tablename * @param po * @throws JDOMException * @throws IOException */public void deleteData(String path, String tablename, Object po)throws JDOMException, IOException {FileInputStream file = new FileInputStream(path);Gson gson = new Gson();SAXBuilder saxBuilder = new SAXBuilder();Document document = saxBuilder.build(file);Element root = document.getRootElement();List<Element> list = root.getChildren();for (Element x : list) {List<Element> al = x.getChildren();if (x.getAttributeValue("name").equals(tablename)) {for (Element s : al) {// 如果定位Data[通过UUID唯一标示]Map mp = gson.fromJson(s.getText(), Map.class);Map newmp = gson.fromJson(gson.toJson(po), Map.class);if (mp.get(_uuid).equals(newmp.get(_uuid))) {x.removeContent(s);break;}}}}XMLOutputter out = new XMLOutputter();out.output(document, new FileOutputStream(path));System.out.println("----------delete --- data --- success----------------------");}/** * 创建数据库 *? * @param path * @throws Exception */public void createDataBase(String path) throws Exception {FileOutputStream file1 = new FileOutputStream(path);Document document = new Document();Element root = new Element("database");Element sort1 = new Element("table");sort1.setAttribute("name", "test");Element sort2 = new Element("table");sort2.setAttribute("name", "system.indexs");Element sort3 = new Element("table");sort3.setAttribute("name", "system.users");root.addContent(sort1);root.addContent(sort2);root.addContent(sort3);document.setRootElement(root);XMLOutputter out = new XMLOutputter();out.output(document, file1);System.out.println("----------create---database---success-------------------");}}?
* 作者： 张代浩 * 技术论坛：[www.jeecg.org](http://www.jeecg.org) * 邮箱： jeecg@sina.com * 交流群：325978980，143858350