java鏈接hive

『壹』 java怎麼創建hivemetastoreclient

下面就來解釋下系統是如何生成meta client的！

先來看幾段代碼！

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();

}

下面要認真分析下上面的這段代碼，因為關聯到一些參數的配置，對於理解生產環境的部署參數有幫助！先看下面這段代碼

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),

『貳』 如何在Java中執行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);
}

『叄』 java中怎麼實現查詢出hive下所有資料庫下表名

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怎麼連接hive資料庫

navicat 不支持鏈接hive庫，只支持連接hive 的metastore 庫，或者成為元數據。
有問題繼續問我

『伍』 如何在Java中執行Hive命令或HiveQL

Java在1.5過後提供了ProcessBuilder根據運行時環境啟動一個Process調用執行運行時環境下的命令或應用程序（1.5以前使用Runtime），關於ProcessBuilder請參考Java相關文檔。調用代碼如下：
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。

『陸』 hive jdbc連接不成功。。報錯org.apache.thrift.transport.TTransportException: Invalid status -128

jdbc和連接池對於你這個場景來說，都足夠，既然用spring管理了，建議還是使用連接池，另外，spring自身沒有實現連接池，一般都是對第三方連接池的包裝，常見的有C3P0，dbcp以及最近比較流行的boneCP等，這幾個配置都差不多太多，以boneCP為例：
<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>