本文整理了Java中javax.jdo.Transaction.begin()方法的一些代码示例，展示了Transaction.begin()的具体用法。这些代码示例主要来源于Github/Stackoverflow/Maven等平台，是从一些精选项目中提取出来的代码，具有较强的参考意义，能在一定程度帮忙到你。Transaction.begin()方法的具体详情如下：
包路径：javax.jdo.Transaction
类名称：Transaction
方法名：begin

Transaction.begin介绍

[英]Begin a transaction. The type of transaction is determined by the setting of the Optimistic flag.
[中]

代码示例

代码示例来源：origin: apache/hive

/**
 * Opens a new one or the one already created Every call of this function must
 * have corresponding commit or rollback function call
 *
 * @return an active transaction
 */
@Override
public boolean openTransaction() {
 openTrasactionCalls++;
 if (openTrasactionCalls == 1) {
  currentTransaction = pm.currentTransaction();
  currentTransaction.begin();
  transactionStatus = TXN_STATUS.OPEN;
 } else {
  // openTransactionCalls > 1 means this is an interior transaction
  // We should already have a transaction created that is active.
  if ((currentTransaction == null) || (!currentTransaction.isActive())){
   throw new RuntimeException("openTransaction called in an interior"
     + " transaction scope, but currentTransaction is not active.");
  }
 }
 boolean result = currentTransaction.isActive();
 debugLog("Open transaction: count = " + openTrasactionCalls + ", isActive = " + result);
 return result;
}

代码示例来源：origin: apache/hive

boolean doCommit = false;
if (!tx.isActive()) {
 tx.begin();
 doCommit = true;

代码示例来源：origin: apache/hive

private boolean runTestQuery() {
 Transaction tx = pm.currentTransaction();
 boolean doCommit = false;
 if (!tx.isActive()) {
  tx.begin();
  doCommit = true;
 }
 Query query = null;
 // Run a self-test query. If it doesn't work, we will self-disable. What a PITA...
 String selfTestQuery = "select \"DB_ID\" from " + DBS + "";
 try {
  prepareTxn();
  query = pm.newQuery("javax.jdo.query.SQL", selfTestQuery);
  query.execute();
  return true;
 } catch (Throwable t) {
  doCommit = false;
  LOG.warn("Self-test query [" + selfTestQuery + "] failed; direct SQL is disabled", t);
  tx.rollback();
  return false;
 } finally {
  if (doCommit) {
   tx.commit();
  }
  if (query != null) {
   query.closeAll();
  }
 }
}

代码示例来源：origin: org.graniteds/granite-server

public Object getCurrentTransaction() {
  Transaction t = pm.currentTransaction();
  t.begin();
  return t;
}

代码示例来源：origin: org.apache.isis.core/isis-core-runtime

public void startTransaction() {
  final javax.jdo.Transaction transaction = persistenceManager.currentTransaction();
  if (transaction.isActive()) {
    throw new IllegalStateException("Transaction already active");
  }
  transaction.begin();
}

代码示例来源：origin: tangram/tangram-jdo

@Override
public void beginTransaction() {
  if (!manager.currentTransaction().isActive()) {
    manager.currentTransaction().begin();
  } // if
} // beginTransaction()

代码示例来源：origin: apache/sentry

private PersistenceManager openTransaction() {
 PersistenceManager pm = pmf.getPersistenceManager();
 Transaction currentTransaction = pm.currentTransaction();
 currentTransaction.begin();
 return pm;
}

代码示例来源：origin: tzaeschke/zoodb

@Before
public void before() {
  TestTools.createDb();
  TestTools.defineSchema(TestClass.class);
  pm = TestTools.openPM(); 
  pm.currentTransaction().begin();
}

代码示例来源：origin: tzaeschke/zoodb

@Before
public void before() {
  TestTools.createDb();
  TestTools.defineSchema(TestClass.class);
  pm = TestTools.openPM(); 
  pm.currentTransaction().begin();
}

代码示例来源：origin: tzaeschke/zoodb

@Before
public void before() {
  TestTools.createDb();
  TestTools.defineSchema(TestClass.class);
  pm = TestTools.openPM(); 
  pm.currentTransaction().begin();
}

代码示例来源：origin: tzaeschke/zoodb

@Test
public void testSchemaName() {
  PersistenceManager pm = TestTools.openPM();
  pm.currentTransaction().begin();
  //create schema
  ZooClass s01 = ZooJdoHelper.schema(pm).addClass(TestClass.class);
  assertEquals(TestClass.class.getName(), s01.getName());
  
  TestTools.closePM();
}

代码示例来源：origin: tzaeschke/zoodb

@Before
public void before() {
  TestTools.createDb();
  TestTools.closePM();
  pm = TestTools.openPM();
  pm.currentTransaction().begin();
  ZooJdoHelper.schema(pm).addClass(TestClassTiny.class);
  ZooJdoHelper.schema(pm).addClass(TestClassTiny2.class);
  pm.currentTransaction().commit();
  pm.currentTransaction().begin();
}

代码示例来源：origin: tzaeschke/zoodb

private void checkResults(String queryFilter, int nRes) {
  pm.currentTransaction().commit();
  pm.currentTransaction().begin();
  Query q = pm.newQuery(TestClass.class, queryFilter);
  Collection<?> c = (Collection<?>) q.execute();
  int n = 0;
  for (Object o: c) {
    assertNotNull(o);
    n++;
  }
  assertEquals(nRes, n);
}

代码示例来源：origin: tzaeschke/zoodb

@Test
public void testSchemaCreationWithNullArray() {
  PersistenceManager pm = TestTools.openPM(props);
  pm.currentTransaction().begin();
  TestClassWithArray t = new TestClassWithArray();
  t.array = null;
  pm.makePersistent(t);
  pm.currentTransaction().commit();
  TestTools.closePM();
}

代码示例来源：origin: tzaeschke/zoodb

@Test
public void testActivationOutsideTx2() {
  PersistenceManager pm = TestTools.openPM();
  pm.currentTransaction().begin();
  pm.currentTransaction().commit();
  pm.close();
  
  TestClass tc = new TestClass();
  tc.setInt(5);
  tc.getInt();
}

代码示例来源：origin: tzaeschke/zoodb

@Test 
public void testThatPrintingDoesntThrowExceptions() {
  pm.currentTransaction().commit();
  pm.currentTransaction().begin();
  ZooClassDef def = getDef(TestClass.class);
  QueryParserV3 qp = new QueryParserV3(
      "(_int > 1 && _int < 52) || _int > 50", def, null, null, 0, Long.MAX_VALUE);
  QueryTreeNode qtn = qp.parseQuery();
  assertNotNull(qtn.print());
}

代码示例来源：origin: tzaeschke/zoodb

@Test 
  public void testThatPrintingDoesntThrowExceptions() {
    pm.currentTransaction().commit();
    pm.currentTransaction().begin();
    ZooClassDef def = getDef(TestClass.class);
    QueryParser qp = new QueryParser("(_int > 1 && _int < 52) || _int > 50", def, null, null);
    QueryTreeNode qtn = qp.parseQuery();
    assertNotNull(qtn.print());
  }
}

代码示例来源：origin: tzaeschke/zoodb

@Test
public void testSchemaCreationHierarchy() {
  PersistenceManager pm = TestTools.openPM(props);
  pm.currentTransaction().begin();
  pm.makePersistent(new TestClassTiny());
  pm.makePersistent(new TestClassTiny2());
  pm.currentTransaction().commit();
  TestTools.closePM();
}

代码示例来源：origin: tzaeschke/zoodb

@Test
public void testQuery() {
  PersistenceManager pm = TestTools.openPM();
  pm.currentTransaction().begin();
  Query q = pm.newQuery();
  assertEquals(pm, q.getPersistenceManager());
  assertFalse(q.isUnmodifiable());
  
  q.setClass(TestClass.class);
  
  testDeclarative(q);
  testString(q);
  
  TestTools.closePM(pm);
}

代码示例来源：origin: tzaeschke/zoodb

@Test
public void testQueryOfExtent() {
  PersistenceManager pm = TestTools.openPM();
  pm.currentTransaction().begin();
  Extent<?> ext = pm.getExtent(TestClass.class);
  Query q = pm.newQuery(ext);
  assertEquals(pm, q.getPersistenceManager());
  assertFalse(q.isUnmodifiable());
  
  
  testDeclarative(q);
  testString(q);
  
  TestTools.closePM(pm);
}