使用morphia实现对mongodb的聚合查询
<?xml version="1.0" encoding="UTF-8"?><beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd"
default-autowire="byName">
<bean scope="singleton" >
<property name="serverIpAddr">
<value>127.0.0.1</value>
</property>
<property name="serverPort">
<value>27017</value>
</property>
<property name="userName">
<value>用户名</value>
</property>
<property name="userPsw">
<value>密码</value>
</property>
<property name="connSource">
<value>库名</value>
</property>
</bean>
<bean scope="singleton" >
<property name="dbName">
<value>库名</value>
</property>
</bean>
</beans>
public>
String dbName;
public String getDbName() {
return dbName;
}
public void setDbName(String dbName) {
this.dbName = dbName;
}
public Datastore getDB() {
Datastore datastore = MongoDBManager.getDB(dbName);
return datastore;
}
public Pagination queryForPage(Pagination pagination, Query query) {
try {
//每页显示条数
int pageSize = pagination.getPageSize();
//第几页
int pageCount = pagination.getPageNo();
//总记录数
int recordCount = pagination.getTotalCount();
//获取总记录数
recordCount = (int) query.count();
//总记录数
pagination.setTotalCount(recordCount);
//第一条数据位置
int firstResult = pagination.getFirstResult();
firstResult = firstResult < 0 ? 0 : firstResult;
FindOptions findOptions = new FindOptions();
//起始位置
findOptions.skip(firstResult);
//查询条数
findOptions.limit(pageSize);
//当前页码
pagination.setPageNo(pagination.getPageNo());
//总页数
pagination.setPageSize(PageHelper.getPageCount(recordCount, pagination.getPageSize()));
List<T> list = query.asList(findOptions);
pagination.setList(list);
return pagination;
} catch (Exception e) {
e.printStackTrace();
Log.logger.error(e.getMessage(), e);
}
return null;
}
public T getOne(Class> try {
Datastore datastore = this.getDB();
Query<T> query = datastore.createQuery(classT);
query = query.field(colName).equal(equalObj);
List<T> list = query.asList();
if (list != null && list.size() > 0)
return list.get(0);
} catch (Exception ex) {
ex.printStackTrace();
Log.logger.error(ex.getMessage(), ex);
}
return null;
}
}
public>
String serverIpAddr="";
int serverPort=0;
String userName="";
String userPsw="";
String connSource="";
public String getServerIpAddr() {
return serverIpAddr;
}
public void setServerIpAddr(String serverIpAddr) {
this.serverIpAddr = serverIpAddr;
}
public int getServerPort() {
return serverPort;
}
public void setServerPort(int serverPort) {
this.serverPort = serverPort;
}
public String getUserName() {
return userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
public String getUserPsw() {
return userPsw;
}
public void setUserPsw(String userPsw) {
this.userPsw = userPsw;
}
public String getConnSource() {
return connSource;
}
public void setConnSource(String connSource) {
this.connSource = connSource;
}
MongoClient mongoClient;
Morphia morphia;
private static MongoDBManager runInstance;
/**
* 初始化连接池
*/
public void initConn() {
// 其他参数根据实际情况进行添加
try {
morphia = new Morphia();
// 告诉Morphia在哪里找到你的类
// 可以为不同的包或者类进行多次的调用
morphia.mapPackage("");
ServerAddress serverAddress = new ServerAddress(serverIpAddr,serverPort);
List<ServerAddress> addrs = new ArrayList<ServerAddress>();
addrs.add(serverAddress);
//MongoCredential.createScramSha1Credential()三个参数分别为 用户名 数据库名称 密码
MongoCredential credential = MongoCredential.createScramSha1Credential(userName, connSource, userPsw.toCharArray());
List<MongoCredential> credentials = new ArrayList<MongoCredential>();
credentials.add(credential);
mongoClient = new MongoClient(addrs,credentials);
runInstance=this;
Log.logger.info("mongoDB 初始化完成 init OK....at:"+ DateUtil.getStandardDate(new Date()));
} catch (Exception e) {
e.printStackTrace();
Log.logger.error("mongoDB 失败,"+e.getMessage(),e);
}
}
public static Datastore getDB(String dbName){
Datastore datastore=null;
if(runInstance.mongoClient!=null&&runInstance.morphia!=null){
datastore = runInstance.morphia.createDatastore(runInstance.mongoClient, dbName);
datastore.ensureIndexes();
}else{
Log.logger.warn("mongoDB 未初始化！");
}
return datastore;
}
}
实体类：
package com.luo.model;
import org.mongodb.morphia.annotations.Entity;
import org.mongodb.morphia.annotations.Id;
@Entity(value = "user_score", noClassnameStored = true)
public> @Id
private Object mgId;
private String name;
private Integer score;
public Object getMgId() {
return mgId;
}
public void setMgId(Object mgId) {
this.mgId = mgId;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Integer getScore() {
return score;
}
public void setScore(Integer score) {
this.score = score;
}
}
//需要封装结果集：
package com.luo.model;
import org.mongodb.morphia.annotations.Entity;
import org.mongodb.morphia.annotations.Id;
@Entity
public> @Id
private Object mgId;
private Integer totalScore;
public Object getMgId() {
return mgId;
}
public void setMgId(Object mgId) {
this.mgId = mgId;
}
public Integer getTotalScore() {
return totalScore;
}
public void setTotalScore(Integer totalScore) {
this.totalScore = totalScore;
}
}
package com.luo.model;
import org.mongodb.morphia.Datastore;
import org.mongodb.morphia.aggregation.AggregationPipeline;
import org.mongodb.morphia.query.Query;
import org.springframework.stereotype.Service;
import javax.annotation.Resource;
import java.util.Iterator;
import static org.mongodb.morphia.aggregation.Group.grouping;
import static org.mongodb.morphia.aggregation.Group.id;
import static org.mongodb.morphia.aggregation.Group.sum;
@Service
public> @Resource
SimpleMongoDBDao<UserDoc> simpleMongoDBDao;
public ScoreGroupDOC getTotalScore(){
Datastore datastore = simpleMongoDBDao.getDB();
Query<UserDoc> query = datastore.createQuery(UserDoc.class);//查询对象
/*获取分数合计*/
AggregationPipeline pipeline = datastore.createAggregation(UserDoc.class)
//封装到结果集的字段 获取聚合的字段
.match(query).group(id(grouping("mgId")),grouping("totalScore", sum("score")));
Iterator<ScoreGroupDOC> iterator = pipeline.aggregate(ScoreGroupDOC.class);
ScoreGroupDOC groupDOC = new ScoreGroupDOC();
while (iterator.hasNext()) {
groupDOC = iterator.next();
}
return groupDOC;
}
}
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