无法通过 jdbc 连接到 hive

Posted 2023-03-22

【中文标题】无法通过 jdbc 连接到 hive

【英文标题】：Can not connect to hive via jdbc

【发布时间】：2015-09-24 12:52:01

【问题描述】：

我使用 gradle 来运行我的程序。示例代码参考https://github.com/onefoursix/Cloudera-Impala-JDBC-Example。

我可以从 repo 运行示例而不会失败。

// Apply the java plugin to add support for Java
apply plugin: 'java'
apply plugin: 'application'

mainClassName = "com.my.impala.fetcher.Fetcher"
// In this section you declare where to find the dependencies of your project
repositories 
    // Use 'jcenter' for resolving your dependencies.
    // You can declare any Maven/Ivy/file repository here.
    mavenCentral()
    maven 
        url "https://repository.cloudera.com/artifactory/cloudera-repos/"
    


run 
     if (project.hasProperty("params")) 
         args params
         // args Eval.me(params)
     


test 
        testLogging 
            events "passed", "skipped", "failed", "standardOut", "standardError"
    



// In this section you declare the dependencies for your production and test code
dependencies 
    // The production code uses the SLF4J logging API at compile time
    compile 'org.slf4j:slf4j-api:1.7.7'
    compile 'org.apache.hadoop:hadoop-client:2.6.0-cdh5.4.4.1'
    compile 'org.json:json:20140107'
    compile 'org.apache.hive:hive-jdbc:1.1.0'

示例代码如下。

Connection con = null;
ResultSet rs = null;
try 
    Class.forName(JDBC_DRIVER_NAME);
    con = DriverManager.getConnection(CONNECTION_HOST);
    Statement stmt = con.createStatement();
    rs = stmt.executeQuery(sqlStatement);
 catch (SQLException e) 
    e.printStackTrace();
    System.exit(-1);
 catch (Exception e) 
    e.printStackTrace();
    System.exit(-1);
 finally 
    try 
        con.close();
     catch (Exception e) 
        e.printStackTrace();
        System.exit(-1);
    


rs.next();

rs.next 会抛出以下异常的地方

org.apache.thrift.transport.TTransportException: Cannot write to null outputStream
    at org.apache.thrift.transport.TiostreamTransport.write(TIOStreamTransport.java:142)
    at org.apache.thrift.protocol.TBinaryProtocol.writeI32(TBinaryProtocol.java:178)
    at org.apache.thrift.protocol.TBinaryProtocol.writeMessageBegin(TBinaryProtocol.java:106)
    at org.apache.thrift.TServiceClient.sendBase(TServiceClient.java:62)
    at org.apache.hive.service.cli.thrift.TCLIService$Client.send_FetchResults(TCLIService.java:495)
    at org.apache.hive.service.cli.thrift.TCLIService$Client.FetchResults(TCLIService.java:487)
    at org.apache.hive.jdbc.HiveQueryResultSet.next(HiveQueryResultSet.java:360)
    at com.my.impala.fetcher.Fetcher.main(Fetcher.java:54)
Exception in thread "main" java.sql.SQLException: Error retrieving next row
    at org.apache.hive.jdbc.HiveQueryResultSet.next(HiveQueryResultSet.java:388)
    at com.my.impala.fetcher.Fetcher.main(Fetcher.java:54)
Caused by: org.apache.thrift.transport.TTransportException: Cannot write to null outputStream
    at org.apache.thrift.transport.TIOStreamTransport.write(TIOStreamTransport.java:142)
    at org.apache.thrift.protocol.TBinaryProtocol.writeI32(TBinaryProtocol.java:178)
    at org.apache.thrift.protocol.TBinaryProtocol.writeMessageBegin(TBinaryProtocol.java:106)
    at org.apache.thrift.TServiceClient.sendBase(TServiceClient.java:62)
    at org.apache.hive.service.cli.thrift.TCLIService$Client.send_FetchResults(TCLIService.java:495)
    at org.apache.hive.service.cli.thrift.TCLIService$Client.FetchResults(TCLIService.java:487)
    at org.apache.hive.jdbc.HiveQueryResultSet.next(HiveQueryResultSet.java:360)
    ... 1 more

我不确定我错过了哪一部分。

谢谢。

【参考方案1】：

您已经关闭了连接，当然您无法读取结果。 rs.next() 应该在 executeQuery() 行之后，在 try 块的末尾，如下所示：

rs = stmt.executeQuery(sqlStatement);
while (rs.next()) 
    // handle the record

ResultSet是一个数据库游标，它不包含整个数据集，你可以通过它访问数据库中的数据。

【讨论】：

这很有帮助。