我用gradle来运行我的程序。引用了示例代码https://github.com/onefoursix/cloudera-impala-jdbc-example.
我可以从回购中运行这个例子,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'
}
下面是示例代码。
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();
哪里 rs.next
将引发以下异常
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
我不知道我错过了哪一部分。
谢谢您。
1条答案
按热度按时间mpbci0fu1#
您已经关闭了连接,当然无法读取结果。这个
rs.next()
应该在executeQuery()
行,在try块的末尾,如下所示:这个
ResultSet
是一个数据库游标,它不包含整个数据集,您可以通过它访问数据库中的数据。