在 Java 中处理 Presto 结果集：'SQLException: Not on a valid row'

Question

我的 Presto plugin 有两个组成部分：

EventListener 记录对 Presto

查询的统计数据

一些 UDFs 用于散列 (MD5, SHA1) 常见数据类型 (varchar, long) 并返回结果 varchar

我已经完成了：

查询日志组件的集成测试 (mvn verify)
哈希 UDF 的单元测试

在 UDF 组件的集成测试中，我尝试通过触发查询来断言我的 UDF 返回的值

Connection connection = DriverManager.getConnection(PRESTO_URL, PRESTO_USER, PRESTO_PASSWORD);
Statement statement = connection.createStatement();
ResultSet resultSet = statement.executeQuery("SELECT SHA1(9223372036854775807) AS hash");
assertEquals("458B642B137E2C76E0B746C6FA43E64C3D4C47F1", resultSet.getString("hash"));

这给出了以下堆栈跟踪 (PrestoResultSet.checkValidRow)

注意：ExtendedHashFunctionsTestIT.java:39 行是包含 resultSet.getString(..)

的行

java.sql.SQLException: Not on a valid row
    at com.facebook.presto.jdbc.PrestoResultSet.checkValidRow(PrestoResultSet.java:1658)
    at com.facebook.presto.jdbc.PrestoResultSet.column(PrestoResultSet.java:1690)
    at com.facebook.presto.jdbc.PrestoResultSet.getString(PrestoResultSet.java:370)
    at com.company.plugin.it.udfs.scalar.hash.ExtendedHashFunctionsTestIT.testBody(ExtendedHashFunctionsTestIT.java:39)
    at com.company.plugin.it.AbstractIntegrationTest.test(AbstractIntegrationTest.java:77)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:85)
    at org.testng.internal.Invoker.invokeMethod(Invoker.java:639)
    at org.testng.internal.Invoker.invokeTestMethod(Invoker.java:816)
    at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:1124)
    at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:125)
    at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:108)
    at org.testng.TestRunner.privateRun(TestRunner.java:774)
    at org.testng.TestRunner.run(TestRunner.java:624)
    at org.testng.SuiteRunner.runTest(SuiteRunner.java:359)
    at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:354)
    at org.testng.SuiteRunner.privateRun(SuiteRunner.java:312)
    at org.testng.SuiteRunner.run(SuiteRunner.java:261)
    at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:52)
    at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:86)
    at org.testng.TestNG.runSuitesSequentially(TestNG.java:1191)
    at org.testng.TestNG.runSuitesLocally(TestNG.java:1116)
    at org.testng.TestNG.run(TestNG.java:1024)
    at org.apache.maven.surefire.testng.TestNGExecutor.run(TestNGExecutor.java:62)
    at org.apache.maven.surefire.testng.TestNGDirectoryTestSuite.execute(TestNGDirectoryTestSuite.java:141)
    at org.apache.maven.surefire.Surefire.run(Surefire.java:180)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.apache.maven.surefire.booter.SurefireBooter.runSuitesInProcess(SurefireBooter.java:350)
    at org.apache.maven.surefire.booter.SurefireBooter.main(SurefireBooter.java:1021)

我很困惑，因为只有当我尝试访问时才会出现错误ResultSet；注释掉 assertEquals(..) 语句让测试运行成功。

更令人不安的是，几乎所有查询的堆栈跟踪都是相同的：

SELECT 'some_string' AS some_alias
SHOW SCHEMAS

我正在使用 Spotify's dockerfile-maven-plugin for the tests. I've put up relevant files in this GitHub Gist

ExtendedHashFunctionsTestIT.java（简化集成测试文件）
pom.xml
Dockerfile

Answer 1

想到我两天的错误就是这个，我感到很遗憾

Connection connection = DriverManager.getConnection(PRESTO_URL, PRESTO_USER, PRESTO_PASSWORD);
Statement statement = connection.createStatement();
ResultSet resultSet = statement.executeQuery("SELECT SHA1(9223372036854775807) AS hash");
resultSet.next();
assertEquals("458B642B137E2C76E0B746C6FA43E64C3D4C47F1", resultSet.getString("hash"));

第 4 行：我在 resultSet.getString(..) 之前错过了 resultSet.next() :-(

在 Java 中处理 Presto 结果集：'SQLException: Not on a valid row'

Processing Presto ResultSet in Java: 'SQLException: Not on a valid row'

testng

integration-testing

resultset

presto

docker