java操作 mongo DB 数据库例子

package com.tompig.ljc;import java.net.UnknownHostException;import java.util.ArrayList;import java.util.Date;import java.util.List;import java.util.Set;import com.mongodb.BasicDBObject;import com.mongodb.DB;import com.mongodb.DBCollection;import com.mongodb.DBCursor;import com.mongodb.DBObject;import com.mongodb.Mongo;import com.mongodb.MongoException;public class DBUtil {String collectionsName = "user_info";String dbName = "ljc";DBCollection coll = null;Mongo m = null;public DBUtil() {try {coll = getDBCollection(collectionsName);} catch (Exception e) {e.printStackTrace();}}public DBCollection getDBCollection(String collectionName) {DBCollection coll = null;try {m = new Mongo("localhost", 27017);DB db = m.getDB(dbName);//if (db.authenticate("ljc", "007".toCharArray())) {//System.out.println("success");//}coll = db.getCollection(collectionName);} catch (UnknownHostException e) {e.printStackTrace();} catch (MongoException e) {e.printStackTrace();}return coll;}// mongo db 删除数据库public void dropDatabase() {try {m.dropDatabase(dbName);} catch (MongoException e) {e.printStackTrace();}}// mongo db查询所有表名public void getAllCollections() {DB db = m.getDB("mydb");Set<String> colls = db.getCollectionNames();for (String s : colls) {System.out.println(s);}}// mongo db 查询索引public void getAllIndex() {List<DBObject> list = coll.getIndexInfo();for (DBObject o : list) {System.out.println(o);}}// mongo db 插入 insertpublic void insert(int i) {BasicDBObject doc = new BasicDBObject();doc.put("name", "liu" + i);doc.put("age", 20 + i);doc.put("sex", "boy");doc.put("time", new Date());coll.insert(doc);}public void batchInsert() {List datas = new ArrayList();for (int i = 0; i < 100; i++) {BasicDBObject bo = new BasicDBObject();bo.put("name", "liu");bo.append("age", i);datas.add(bo);}coll.insert(datas);}// 查询单个public void findOne() {BasicDBObject obj = (BasicDBObject) coll.findOne();System.out.println(obj);}// mongo db 修改public void update() {BasicDBObject query = new BasicDBObject();query.put("name", "liu");DBObject stuFound = coll.findOne(query);stuFound.put("name", stuFound.get("name") + "update_1");coll.update(query, stuFound);}// 查询所有public void queryAll() {BasicDBObject obj = new BasicDBObject();obj.put("sex", "boy");DBCursor cursor = coll.find(obj);while (cursor.hasNext()) {String name = (String) cursor.next().get("name");System.out.println(name);}cursor.close();}// 条件删除public void delete(String name) {BasicDBObject query = new BasicDBObject();query.put("name", name);// 找到并且删除，并返回删除的对象DBObject removeObj = coll.findAndRemove(query);System.out.println(removeObj);}// 条件查询public void findByName(String name) {BasicDBObject obj = new BasicDBObject();obj.put("name", name);DBCursor cursor = coll.find(obj);while (cursor.hasNext()) {System.out.println(cursor.next());}}//条件查询2public void argsFind(){BasicDBObject condition = new BasicDBObject();//condition.put("age", new BasicDBObject("$gt", 20).append("$lte", 30)); condition.put("age", new BasicDBObject("$gt", 50));coll.find(condition);//比较符//"$gt"： 大于//"$gte"：大于等于//"$lt"： 小于//"$lte"：小于等于//"$in"： 包含//以下条件查询20<age<=30}// 分页查询public void pageQuery() {DBCursor cursor = coll.find().skip(0).limit(10);while (cursor.hasNext()) {System.out.println(cursor.next());}}}