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转载 http://shensy.iteye.com/blog/1545335、
在工作中使用到了MongoDB,平时也看了一些资料,感觉MongoDB官网内develop zone有个不错的manual,很多资料都可以查到,地址如下:http://www.mongodb.org/display/DOCS/Manual
另外,本blog主要记录一下使用mongodb java driver来访问数据库的一些总结。
主要是由createMongoInstance()方法完成初始化工作。
Java代码 
- protectedstaticfinal Mongo mongoInstance = createMongoInstance();
- privatestatic Mongo createMongoInstance() {
- MongoOptions mo = new MongoOptions();
- mo.socketKeepAlive=true;
- mo.autoConnectRetry = true;
- mo.maxAutoConnectRetryTime=10;
- mo.connectionsPerHost = 40;
- mo.connectTimeout = 20 * 1000;
- mo.socketTimeout = 60 * 1000;
- try {
- if (DatabaseProject.DB_CONFIG.containsKey("mongodb.ips")) {
- returnnew Mongo(getServerAddrsFromConf("mongodb"),mo);
- }
- returnnew Mongo(new ServerAddress(DatabaseProject.DB_CONFIG.getString("mongodb.ip"), DatabaseProject.DB_CONFIG.getInt("mongodb.port")),mo);
- } catch (Throwable e) {
- DatabaseProject.LOGGER.error("Failed to init mongodb", e);
- thrownew ExceptionInInitializerError(e);
- }
- }
其中有一些数据库配置直接写在配置文件里了,在MongoJavaDriverDAO中初始化一部分数据:
Java代码 
- publicvoid insertCollData(){
- //如果该collection不存在则会自动创建
- DBCollection parentcoll = getCollection("ParentColl");
- DBCollection childcoll = getCollection("ChildColl");
- for(int i=0;i
- coll = getCollection("ParentColl");
- DBCursor cur = coll.find(new BasicDBObject("_id", new ObjectId(id)));//直接用string查不出来
- while(cur.hasNext()){
- System.out.println(cur.next());
- }
- }
- /**
- * And多条件查询
- */
- publicvoid findByAndQuery(int intData,long longData){
- coll = getCollection("ParentColl");
- BasicDBObject query = new BasicDBObject();
- query.put("intData", intData);
- query.put("longData", longData);
- System.out.println(coll.findOne(query));
- }
- /**
- * OR多条件查询
- */
- publicvoid findByORQuery(int lte,int gt,long longData){
- coll = getCollection("ParentColl");
- BasicDBObject query=new BasicDBObject();
- BasicDBObject longdata = new BasicDBObject("longData", longData);
- BasicDBObject intdata = new BasicDBObject("intData", new BasicDBObject().append("$gt", gt).append("$lte",lte));
- BasicDBList cond=new BasicDBList();
- cond.add(longdata);
- cond.add(intdata);
- query.put("$or", cond);
- DBCursor cur = coll.find(query);
- while(cur.hasNext()){
- System.out.println(cur.next());
- }
- }
- /**
- * IN查询
- */
- publicvoid findByINQuery(int value1,int value2){
- coll = getCollection("ParentColl");
- BasicDBObject query=new BasicDBObject();
- BasicDBList cond=new BasicDBList();
- cond.add(value1);
- cond.add(value2);
- query.put("intData",new BasicDBObject("$in", cond));
- DBCursor cur = coll.find(query);
- while(cur.hasNext()){
- System.out.println(cur.next());
- }
- }
- /**
- * NOT查询
- */
- publicvoid findByNotQuery(int value1,int value2){
- coll = getCollection("ParentColl");
- BasicDBObject query=new BasicDBObject();
- BasicDBList cond=new BasicDBList();
- cond.add(value1);
- cond.add(value2);
- query.put("intData",new BasicDBObject("$nin", cond));
- System.out.println("Count:"+coll.find(query).count());
- }
- /**
- * 获取结果集第一条
- */
- publicvoid fetchFirstQuery(int value1,int value2){
- coll = getCollection("ParentColl");
- BasicDBList cond = new BasicDBList();
- cond.add(value1);
- cond.add(value2);
- BasicDBObject query = new BasicDBObject().append("intData",new BasicDBObject("$nin",cond));
- System.out.println(coll.findOne(query));
- }
- /**
- * 查询文档部分列
- */
- publicvoid querySomeKey(){
- coll = getCollection("ParentColl");
- DBCursor cur = coll.find(new BasicDBObject(),new BasicDBObject("intData",true));
- while(cur.hasNext()){
- System.out.println(cur.next());
- }
- }
- /**
- * 查询内嵌文档
- */
- publicvoid queryInnerDocument(){
- coll = getCollection("ParentColl");
- BasicDBObject map = new BasicDBObject();
- map.put("innertype","string");
- map.put("innerContent","string0");
- DBCursor cur = coll.find(new BasicDBObject("documentData",map));
- while(cur.hasNext()){
- System.out.println(cur.next());
- }
- }
- /**
- * 查询内嵌部分文档
- */
- publicvoid querySubInnerDocument(){
- coll = getCollection("ParentColl");
- DBCursor cur = coll.find(new BasicDBObject("documentData.innerContent","string0"));
- while(cur.hasNext()){
- System.out.println(cur.next());
- }
- }
- /**
- * 查询分页文档
- */
- publicvoid queryByPage(int skipNum,int pageNum){
- coll = getCollection("ParentColl");
- DBCursor cur = coll.find().skip(skipNum).limit(pageNum);
- while(cur.hasNext()){
- System.out.println(cur.next());
- }
- }
- /**
- * 查询文档某列是否存在
- */
- publicvoid queryExists(){
- coll = getCollection("ParentColl");
- DBCursor cur = coll.find(new BasicDBObject("longData",new BasicDBObject("$exists",true)));
- while(cur.hasNext()){
- System.out.println(cur.next());
- }
- }
- /**
- * 查询文档排序
- */
- publicvoid sortDocument(){
- coll = getCollection("ParentColl");
- DBCursor cur = coll.find().sort(new BasicDBObject("intData",-1));//1:asc / -1:desc
- while(cur.hasNext()){
- System.out.println(cur.next());
- }
- }
补充distinct查询:
Java代码 
- /**
- * 获取根据某元素做distinct查询.
- */
- publicvoid distinctKey(){
- coll = getCollection("ParentColl");
- List list = coll.distinct("documentData.innertype");
- for(String str:list){
- System.out.println(str);
- }
- }
不难发现主要用到BasicDBObject、BasicDBList、DBCursor这三个类。BasicDBObject好比一个map,好比使用json查询中的{} 。BasicDBList是个list,用于or,nin等条件查询。DBCursor用于遍历结果集。其实只要将对应的json查询使用这3个类转化一下,就能写出对应的java代码了。
更新相关:
Java代码 
- /**
- * 更新文档1
- */
- publicvoid updateDocument(){
- DB db = getDB();
- //由于mongodb中使用连接池的原因,getLastError()需要再次从连接池中获取连接.
- //保证update操作和getLastError()使用同一个连接.
- db.requestStart();
- coll = db.getCollection("ParentColl");
- WriteResult result = coll.update(new BasicDBObject("intData",1100),new BasicDBObject("$set", new BasicDBObject("booleanData",false)));
- System.out.println("update count:"+result.getN());
- if(result.getLastError().ok()){//获取上次操作结果是否有错误.
- System.out.println("update document success.");
- }else{
- System.out.println(result.getLastError().getErrorMessage());
- }
- db.requestDone();
- }
- /**
- * 更新文档2
- */
- publicvoid updateMultiDocument(){
- DB db = getDB();
- db.requestStart();
- coll = db.getCollection("ParentColl");
- //第三个参数:如果没有该文档是否创建,第四个参数:是否更新全部匹配条件的文档.
- WriteResult result = coll.update(new BasicDBObject("booleanData",false),new BasicDBObject("$set", new BasicDBObject("booleanData",true)),false,true);
- System.out.println("update count:"+result.getN());
- if(result.getLastError().ok()){//获取上次操作结果是否有错误.
- System.out.println("update document success.");
- }else{
- System.out.println(result.getLastError().getErrorMessage());
- }
- db.requestDone();
- }
注意requestStart、requestDone方法保证使用同一个数据库连接。WriteResult记录更新结果。
索引相关:
Java代码 
- /**
- * 创建唯一索引
- */
- publicvoid createIndexes(){
- coll = getCollection("ParentColl");
- BasicDBObject index = new BasicDBObject();
- index.put("intData",1);//1:asc / -1:desc
- index.put("unique",true);//唯一索引
- coll.createIndex(index);
- }
- /**
- * 查询索引信息
- */
- publicvoid getIndexes(){
- coll = getCollection("ParentColl");
- List indexInfo = coll.getIndexInfo();
- System.out.println(indexInfo);
- }
- /**
- * 删除索引信息
- */
- publicvoid dropIndexes(){
- coll = getCollection("ParentColl");
- //删除的索引必须跟创建的索引名称\排序\是否唯一都相同才能删除
- BasicDBObject index = new BasicDBObject();
- index.put("intData",1);
- index.put("unique",true);
- coll.dropIndex(index);
- }
对于文档可能还会对数组操作:
Java代码 
- /**
- * 取出文档中的数组
- */
- publicvoid queryArray(){
- coll = getCollection("ChildColl");
- DBCursor cur = coll.find(new BasicDBObject(),new BasicDBObject("arrays",1));
- while(cur.hasNext()){
- BasicDBObject bo = (BasicDBObject)cur.next();
- List list = (List)bo.get("arrays");
- System.out.println(list.toString());
- }
- }
- /**
- * 查询数组内是否包含某元素
- */
- publicvoid queryElementInArray(){
- coll = getCollection("ChildColl");
- BasicDBObject query = new BasicDBObject();
- BasicDBObject obj = new BasicDBObject();
- obj.put("arr0",0);
- query.put("arrays", new BasicDBObject("$elemMatch",obj));
- DBCursor cur = coll.find(query);
- while(cur.hasNext()){
- System.out.println(cur.next());
- }
- }
- /**
- * 数组内包含元素的值
- */
- publicvoid queryElementArray(){
- coll = getCollection("ChildColl");
- BasicDBObject obj = new BasicDBObject();
- obj.put("arrays", "str0");
- obj.put("arrays.arr0",0);
- obj.put("arrays.arr10",10);
- DBCursor cur = coll.find(obj);
- while(cur.hasNext()){
- System.out.println(cur.next());
- }
- }
- /**
- * push(pushAll) array element
- */
- publicvoid pushElementInArray(String _id){
- DB db = getDB();
- db.requestStart();
- coll = getCollection("ChildColl");
- //WriteResult result = coll.update(new BasicDBObject("_id", new ObjectId(_id)),new BasicDBObject("$push",new BasicDBObject("arrays",new BasicDBObject("arr99","99"))));
- List list=new ArrayList();
- list.add(new BasicDBObject("arr99",99));
- list.add(new BasicDBObject("arr100",100));
- WriteResult result = coll.update(new BasicDBObject("_id", new ObjectId(_id)),new BasicDBObject("$pushAll",new BasicDBObject("arrays",list)));
- System.out.println("update count:"+result.getN());
- if(result.getLastError().ok()){
- System.out.println("update document success.");
- }else{
- System.out.println(result.getLastError().getErrorMessage());
- }
- db.requestDone();
- }
- /**
- * pull(pullAll) array element
- */
- publicvoid pullElementInArray(String _id){
- DB db = getDB();
- db.requestStart();
- coll = getCollection("ChildColl");
- List list=new ArrayList();
- list.add(new BasicDBObject("arr99",99));
- list.add(new BasicDBObject("arr100",100));
- //WriteResult result = coll.update(new BasicDBObject("_id", new ObjectId(_id)),new BasicDBObject("$pull",new BasicDBObject("arrays",new BasicDBObject("arr100",100))));
- WriteResult result = coll.update(new BasicDBObject("_id", new ObjectId(_id)),new BasicDBObject("$pullAll",new BasicDBObject("arrays",list)));
- System.out.println("update count:"+result.getN());
- db.requestDone();
- }
- /**
- * pop array element(1,last;-1,first)
- */
- publicvoid popElementInArray(String _id){
- coll = getCollection("ChildColl");
- WriteResult result = coll.update(new BasicDBObject("_id", new ObjectId(_id)),new BasicDBObject("$pop",new BasicDBObject("arrays",-1)));//1,last;-1,first
- System.out.println("update count:"+result.getN());
- }
- /**
- * addToSet And Each array element
- */
- publicvoid addToSetAndEachElementInArray(String _id){
- coll = getCollection("ChildColl");
- List list = new ArrayList();
- list.add("str0");
- list.add("str1");
- list.add(new BasicDBObject("arr99",99));
- WriteResult result = coll.update(new BasicDBObject("_id", new ObjectId(_id)),new BasicDBObject("$addToSet",new BasicDBObject("arrays",new BasicDBObject("$each",list))));//1,last;-1,first
- System.out.println("update count:"+result.getN());
- }
- /**
- * 按数组位置更新文档(查询条件需要包含更新内容,$为数组位置占位符,只更新匹配到的第一个文档.)
- */
- publicvoid updatePositionInArray(String _id){
- coll = getCollection("ChildColl");
- WriteResult result = coll.update(new BasicDBObject("arrays.arr0", 100),new BasicDBObject("$set",new BasicDBObject("arrays.$.arr0",101)));
- System.out.println("update count:"+result.getN());
- }
以上都是一些基本的查询、更新操作,当然还有一些如map reduce和关联查询等复杂的方法,我将另写一篇blog总结一下。
参考文献包括:《mongodb权威指南》、《mongodb管理与开发精要》,另外文章开头提到的MongoDB官网内的develop zone也是很不错的资料来源。
PS:
mongodb driver在线API文档: http://api.mongodb.org/java/2.8.0/ (目前是2.8.0)
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