Question

我有一个使用hibernate管理数据库操作的java web项目。

按顺序执行了两个SQL：

执行＆＃34; CREATE TEMP temp_table ......;＆＃34;通过hibernate本机sql查询。
执行＆＃34;从SDTIN＆＃34;复制temp_table;通过org.postgresql.copy.CopyManager将csv文件传输到temp_table。

我的代码：

public boolean loadElectricFishData(Integer fileId, File eventfile, File samplefile) {
    Session session = stagingSessionFactory.getCurrentSession();
    String elecCountTableName = "temp_eb_elec_count_" + fileId;

    return createTable(session, elecCountTableName , "nemostaging.eb_elec_count")
            && copyTableFromCSV(session, elecCountTableName, eventfile) ? true : false;
}

private boolean createTable(Session session, String tableName, String likeTableName) {
    SQLQuery query = session.createSQLQuery("CREATE TABLE nemostaging." + tableName + " (LIKE " + likeTableName + " INCLUDING ALL)");
    query.executeUpdate();
    session.flush();
    session.close();
    return true;
}

private boolean copyTableFromCSV(Session session, final String tableName, final File csv) {
    SessionImpl sessionImpl = (SessionImpl)session;
    Connection connection = sessionImpl.getTransactionCoordinator().getJdbcCoordinator().getLogicalConnection().getConnection();
    FileReader fileReader = null;
    try {
        CopyManager copyManager = new CopyManager((BaseConnection) connection);
        fileReader = new FileReader(csv);
        copyManager.copyIn("COPY nemostaging." + tableName + " FROM STDIN DELIMITER ',' CSV HEADER", fileReader);
    } catch (SQLException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (FileNotFoundException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } finally {
        if (fileReader != null) {
            try {
                fileReader.close();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }

    return false;
}

我的问题是我需要为这两个操作使用相同的会话，因为临时表对另一个会话是不可见的。而CopyManager不会重用相同的会话。任何人都知道如何指示org.postgresql.copy.CopyManager的当前会话，但不仅仅是当前连接？

非常感谢！

------更新-二○一五年十一月一十三日----- 嗨Craig Ringer，我尝试了你的建议，但有例外：

java.lang.reflect.UndeclaredThrowableException 在com.sun.proxy。$ Proxy20.unwrap（未知来源） at nz.co.niwa.nemo.uploadservice.core.dao.impl.StagingLoadDataDaoImpl $ 1.execute（StagingLoadDataDaoImpl.java:88）在org.hibernate.jdbc.WorkExecutor.executeWork（WorkExecutor.java:54）在org.hibernate.internal.SessionImpl $ 2.accept（SessionImpl.java:1933）在org.hibernate.internal.SessionImpl $ 2.accept（SessionImpl.java:1930） at org.hibernate.engine.jdbc.internal.JdbcCoordinatorImpl.coordinateWork（JdbcCoordinatorImpl.java:211）在org.hibernate.internal.SessionImpl.doWork（SessionImpl.java:1951）在org.hibernate.internal.SessionImpl.doWork（SessionImpl.java:1937） at nz.co.niwa.nemo.uploadservice.core.dao.impl.StagingLoadDataDaoImpl.loadSpotlightData（StagingLoadDataDaoImpl.java:85） at sun.reflect.NativeMethodAccessorImpl.invoke0（Native Method） at sun.reflect.NativeMethodAccessorImpl.invoke（NativeMethodAccessorImpl.java:39） at sun.reflect.DelegatingMethodAccessorImpl.invoke（DelegatingMethodAccessorImpl.java:25）在java.lang.reflect.Method.invoke（Method.java:597）在org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection（AopUtils.java:319）在org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint（ReflectiveMethodInvocation.java:183）在org.springframework.aop.framework.ReflectiveMethodInvocation.proceed（ReflectiveMethodInvocation.java:150）在org.springframework.transaction.interceptor.TransactionInterceptor.invoke（TransactionInterceptor.java:110）在org.springframework.aop.framework.ReflectiveMethodInvocation.proceed（ReflectiveMethodInvocation.java:172）在org.springframework.transaction.interceptor.TransactionInterceptor.invoke（TransactionInterceptor.java:110）在org.springframework.aop.framework.ReflectiveMethodInvocation.proceed（ReflectiveMethodInvocation.java:172）在org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke（ExposeInvocationInterceptor.java:90）在org.springframework.aop.framework.ReflectiveMethodInvocation.proceed（ReflectiveMethodInvocation.java:172）在org.springframework.aop.framework.JdkDynamicAopProxy.invoke（JdkDynamicAopProxy.java:202）在com.sun.proxy。$ Proxy14.loadSpotlightData（未知来源） at nz.co.niwa.nemo.uploadservice.core.manage.impl.StagingLoadDataManageImpl.loadSpotlightData（StagingLoadDataManageImpl.java:30） at nz.co.niwa.nemo.uploadservice.core.service.impl.StagingLoadDataServiceImpl.loadSpotlightData（StagingLoadDataServiceImpl.java:44） at nz.co.niwa.nemo.uploadservice.core.test.service.StagingLoadDataServiceTest.testLoadSpotlightData（StagingLoadDataServiceTest.java:39） at sun.reflect.NativeMethodAccessorImpl.invoke0（Native Method） at sun.reflect.NativeMethodAccessorImpl.invoke（NativeMethodAccessorImpl.java:39） at sun.reflect.DelegatingMethodAccessorImpl.invoke（DelegatingMethodAccessorImpl.java:25）在java.lang.reflect.Method.invoke（Method.java:597）在org.junit.runners.model.FrameworkMethod $ 1.runReflectiveCall（FrameworkMethod.java:45）在org.junit.internal.runners.model.ReflectiveCallable.run（ReflectiveCallable.java:15）在org.junit.runners.model.FrameworkMethod.invokeExplosively（FrameworkMethod.java:42）在org.junit.internal.runners.statements.InvokeMethod.evaluate（InvokeMethod.java:20）在org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate（RunBeforeTestMethodCallbacks.java:74）在org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate（RunAfterTestMethodCallbacks.java:83）在org.springframework.test.context.junit4.statements.SpringRepeat.evaluate（SpringRepeat.java:72）在org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild（SpringJUnit4ClassRunner.java:231）在org.junit.runners.BlockJUnit4ClassRunner.runChild（BlockJUnit4ClassRunner.java:47）在org.junit.runners.ParentRunner $ 3.run（ParentRunner.java:231）在org.junit.runners.ParentRunner $ 1.schedule（ParentRunner.java:60）在org.junit.runners.ParentRunner.runChildren（ParentRunner.java:229）在org.junit.runners.ParentRunner.access $ 000（ParentRunner.java:50）在org.junit.runners.ParentRunner $ 2.evaluate（ParentRunner.java:222）在org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate（RunBeforeTestClassCallbacks.java:61）在org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate（RunAfterTestClassCallbacks.java:71）在org.junit.runners.ParentRunner.run（ParentRunner.java:300）在org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run（SpringJUnit4ClassRunner.java:174）在org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run（JUnit4TestReference.java:50）在org.eclipse.jdt.internal.junit.runner.TestExecution.run（TestExecution.java:38）在org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests（RemoteTestRunner.java:459）在org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests（RemoteTestRunner.java:675）在org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run（RemoteTestRunner.java:382）在org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main（RemoteTestRunner.java:192）引起：java.lang.reflect.InvocationTargetException at sun.reflect.NativeMethodAccessorImpl.invoke0（Native Method） at sun.reflect.NativeMethodAccessorImpl.invoke（NativeMethodAccessorImpl.java:39） at sun.reflect.DelegatingMethodAccessorImpl.invoke（DelegatingMethodAccessorImpl.java:25）在java.lang.reflect.Method.invoke（Method.java:597）在org.hibernate.engine.jdbc.internal.proxy.ConnectionProxyHandler.continueInvocation（ConnectionProxyHandler.java:130）在org.hibernate.engine.jdbc.internal.proxy.AbstractProxyHandler.invoke（AbstractProxyHandler.java:81） ......还有55个引起：java.sql.SQLException：无法解包到org.postgresql.copy.CopyManager at org.postgresql.jdbc4.AbstractJdbc4Connection.unwrap（AbstractJdbc4Connection.java:269） ......还有61个

我的代码：

public boolean loadSpotlightData(final Integer fileId, final File datafile) {
    final String spotCountTableName = "tmp_eb_spot_count_" + fileId;
    Session session = stagingSessionFactory.getCurrentSession();
    SQLQuery query = session.createSQLQuery("CREATE TEMP TABLE " + spotCountTableName + " (LIKE nemostaging.eb_spot_count INCLUDING ALL)");
    query.executeUpdate();
    session.doWork(new Work() {
        @Override
        public void execute(Connection connection) throws SQLException {
            CopyManager copyManager = connection.unwrap(org.postgresql.copy.CopyManager.class);
            FileReader fileReader = null;
            try {
                fileReader = new FileReader(datafile);
                copyManager.copyIn("COPY " + spotCountTableName + " FROM STDIN DELIMITER ',' CSV HEADER", fileReader);
            } catch (SQLException e) {
                LOG.error("Errors occur while COPY nemostaging." + spotCountTableName + " FROM STDIN DELIMITER ',' CSV HEADER;", e);
            } catch (FileNotFoundException e) {
                LOG.error("The CSV file cannot be found while copying into database.", e);
            } catch (IOException e) {
                LOG.error("Errors occur while reading the csv file.", e);
            } finally {
                if (fileReader != null) {
                    try {
                        fileReader.close();
                    } catch (IOException e) {
                        LOG.error("Errors occur while closing file reader.", e);
                    }
                }
            }
        }
    });

    Query query1 = session.getNamedQuery("staging.loadSpotlightData");
    query1.setParameter("fileId", fileId);
    query1.list();

    return true;
}

Answer 1

你必须做的是运行Hibernate查询，然后要求Hibernate Session获取实现Connection 的基础org.postgresql.PGConnection对象并使用它。

您曾经能够使用Session.connection()方法解包会话，但现在已弃用。而是use the doWork API。您传递的java.sql.Connection可能也包含在您的连接池中，因此您可能需要解包它以获取实际的连接对象。如果您正在使用JDBC4驱动程序和池（您应该），Wrapper Connection实现了unwrap(org.postgresql.copy.CopyManager.class)接口，例如： session.doWork( new Work() { public void execute(Connection connection) throws SQLException { CopyManager cm = connection.unwrap(org.postgresql.copy.CopyManager.class); ... do stuff ... } } );。

像（未经测试）的东西：

DriverManager

您无法直接从bazel run -c opt //tensorflow/models/rnn/translate:translate -- \ --data_dir ./data_dir --train_dir ./checkpoints_directory \ --en_vocab_size=40000 --fr_vocab_size=40000创建新的单独连接，并将其与其他会话的临时表一起使用。你也不需要。最好从Hibernate会话中解开池连接。

如何向Postgresql CopyManager

1 个答案: