java链接hive

『壹』 java怎么创建hivemetastoreclient

下面就来解释下系统是如何生成meta client的！

先来看几段代码！

publicvoidcreateDatabase(Databasedb,booleanifNotExist)throwsAlreadyExistsException,HiveException{

try{

getMSC().createDatabase(db);

}catch(AlreadyExistsExceptione){

if(!ifNotExist){

throwe;

}

}catch(Exceptione){

thrownewHiveException(e);

}

}

=========

privateIMetaStoreClientgetMSC()throwsMetaException{

if(metaStoreClient==null){

metaStoreClient=createMetaStoreClient();

}

returnmetaStoreClient;

}

=========

()throwsMetaException{

HiveMetaHookLoaderhookLoader=newHiveMetaHookLoader(){

publicHiveMetaHookgetHook(org.apache.hadoop.hive.metastore.api.Tabletbl)throwsMetaException{

try{

if(tbl==null){

returnnull;

}

=HiveUtils.getStorageHandler(conf,

tbl.getParameters().get(META_TABLE_STORAGE));

if(storageHandler==null){

returnnull;

}

returnstorageHandler.getMetaHook();

}catch(HiveExceptionex){

LOG.error(StringUtils.stringifyException(ex));

thrownewMetaException("Failedtoloadstoragehandler:"+ex.getMessage());

}

}

};

returnnewHiveMetaStoreClient(conf,hookLoader);

}

=========

publicHiveMetaStoreClient(HiveConfconf,HiveMetaHookLoaderhookLoader)

throwsMetaException{

this.hookLoader=hookLoader;

if(conf==null){

conf=newHiveConf(HiveMetaStoreClient.class);

}

this.conf=conf;

localMetaStore=conf.getBoolVar(ConfVars.METASTORE_MODE);

if(localMetaStore){

//

//throughthenetwork

client=newHiveMetaStore.HMSHandler("hiveclient",conf);

isConnected=true;

return;

}

//getthenumberretries

retries=HiveConf.getIntVar(conf,HiveConf.ConfVars.METASTORETHRIFTRETRIES);

retryDelaySeconds=conf.getIntVar(ConfVars.METASTORE_CLIENT_CONNECT_RETRY_DELAY);

//

if(conf.getVar(HiveConf.ConfVars.METASTOREURIS)!=null){

StringmetastoreUrisString[]=conf.getVar(

HiveConf.ConfVars.METASTOREURIS).split(",");

metastoreUris=newURI[metastoreUrisString.length];

try{

inti=0;

for(Strings:metastoreUrisString){

URItmpUri=newURI(s);

if(tmpUri.getScheme()==null){

("URI:"+s

+"doesnothaveascheme");

}

metastoreUris[i++]=tmpUri;

}

}catch(IllegalArgumentExceptione){

throw(e);

}catch(Exceptione){

MetaStoreUtils.logAndThrowMetaException(e);

}

}elseif(conf.getVar(HiveConf.ConfVars.METASTOREDIRECTORY)!=null){

metastoreUris=newURI[1];

try{

metastoreUris[0]=newURI(conf

.getVar(HiveConf.ConfVars.METASTOREDIRECTORY));

}catch(URISyntaxExceptione){

MetaStoreUtils.logAndThrowMetaException(e);

}

}else{

LOG.error("NOTgettingurisfromconf");

thrownewMetaException("");

}

//finallyopenthestore

open();

}

下面要认真分析下上面的这段代码，因为关联到一些参数的配置，对于理解生产环境的部署参数有帮助！先看下面这段代码

localMetaStore=conf.getBoolVar(ConfVars.METASTORE_MODE);

if(localMetaStore){

//

//connecting

//throughthenetwork

client=newHiveMetaStore.HMSHandler("hiveclient",conf);

isConnected=true;

return;

}

PS:ConfVars.METASTORE_MODE---METASTORE_MODE("hive.metastore.local",true),

『贰』 如何在Java中执行Hive命令或HiveQL

String sql="show tables; select * from test_tb limit 10";
List<String> command = new ArrayList<String>();
command.add("hive");
command.add("-e");
command.add(sql);
List<String> results = new ArrayList<String>();
ProcessBuilder hiveProcessBuilder = new ProcessBuilder(command);
hiveProcess = hiveProcessBuilder.start();
BufferedReader br = new BufferedReader(new InputStreamReader(
hiveProcess.getInputStream()));
String data = null;
while ((data = br.readLine()) != null) {
results.add(data);
}

『叁』 java中怎么实现查询出hive下所有数据库下表名

try {
Class.forName("org.apache.hadoop.hive.jdbc.HiveDriver");

String selectSql = "select * from db.data where address = '11111111'";
Connection connect = DriverManager.getConnection("jdbc:hive://192.168.xx.xx:10000/db", "xxx", "xxx");
PreparedStatement state = null;
state = connect.prepareStatement(selectSql);
ResultSet resultSet = state.executeQuery();
while (resultSet != null && resultSet.next()) {
System.out.println(resultSet.getString(1) + " " + resultSet.getString(2));
}
} catch (Exception e) {
e.printStackTrace();
}

『肆』 navicat for mysql怎么连接hive数据库

navicat 不支持链接hive库，只支持连接hive 的metastore 库，或者成为元数据。
有问题继续问我

『伍』 如何在Java中执行Hive命令或HiveQL

Java在1.5过后提供了ProcessBuilder根据运行时环境启动一个Process调用执行运行时环境下的命令或应用程序（1.5以前使用Runtime），关于ProcessBuilder请参考Java相关文档。调用代码如下：
String sql="show tables; select * from test_tb limit 10";
List<String> command = new ArrayList<String>();
command.add("hive");
command.add("-e");
command.add(sql);
List<String> results = new ArrayList<String>();
ProcessBuilder hiveProcessBuilder = new ProcessBuilder(command);
hiveProcess = hiveProcessBuilder.start();
BufferedReader br = new BufferedReader(new InputStreamReader(
hiveProcess.getInputStream()));
String data = null;
while ((data = br.readLine()) != null) {
results.add(data);
}
其中command可以是其它Hive命令，不一定是HiveQL。

『陆』 hive jdbc连接不成功。。报错org.apache.thrift.transport.TTransportException: Invalid status -128

jdbc和连接池对于你这个场景来说，都足够，既然用spring管理了，建议还是使用连接池，另外，spring自身没有实现连接池，一般都是对第三方连接池的包装，常见的有C3P0，dbcp以及最近比较流行的boneCP等，这几个配置都差不多太多，以boneCP为例：
<bean id="dataSource" class="com.jolbox.bonecp.BoneCPDataSource"
destroy-method="close">
<property name="driverClass" value="${jdbc.driverClass}" />
<property name="jdbcUrl" value="${jdbc.url}" />
<property name="username" value="${jdbc.user}" />
<property name="password" value="${jdbc.password}" />
<property name="idleConnectionTestPeriod" value="60" />
<property name="idleMaxAge" value="240" />
<property name="maxConnectionsPerPartition" value="30" />
<property name="minConnectionsPerPartition" value="10" />
<property name="partitionCount" value="2" />
<property name="acquireIncrement" value="5" />
<property name="statementsCacheSize" value="100" />
<property name="releaseHelperThreads" value="3" />
</bean>
<bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
<property name="dataSource" ref="dataSource" />
</bean>