[置顶] 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 insert
public 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2
public 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());
}
}
}