Package db

Class Transaction

java.lang.Object
db.Transaction
All Implemented Interfaces:
AutoCloseable
public abstract class Transaction extends Object implements AutoCloseable
Provides syntax for opening a database transaction using a try-with-resources block

For example, using DBHandle.startTransaction() directly: 

 int txid = dbHandle.startTransaction();
 try {
        // ... Do something
 }
 finally {
        program.endTransaction(txid, true);
 }

Can be expressed using an an Transaction instead: 

 try (Transaction tx = dbHandle.openTransaction(dbErrorHandler)) {
        // ... Do something
 }

  • Constructor Summary

    Constructors
    Modifier
    Constructor
    Description
    protected
    Transaction()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    abort()
    Mark transaction for rollback/non-commit and end transaction if active.
    void
    abortOnClose()
    Mark transaction for rollback/non-commit upon closing.
    void
    close()
    End this transaction if active using the current commit state.
    void
    commit()
    Mark transaction for commit and end transaction if active.
    void
    commitOnClose()
    Mark transaction for commit upon closing.
    protected abstract boolean
    endTransaction(boolean commit)
    End this transaction if currently active.
    boolean
    isSubTransaction()
    Determine if this is a sub-transaction to a larger transaction.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • Transaction

      protected Transaction()

  • Method Details

    • endTransaction

      protected abstract boolean endTransaction(boolean commit)
      End this transaction if currently active.
      Parameters:
      commit - true if changes should be commited, false if all changes in this transaction should be discarded (i.e., rollback). If this is a "sub-transaction" and commit is false, the larger transaction will rollback upon completion.
      Returns:
      true if changes have been commited or false if nothing to commit or commit parameter was specified as false.

    • isSubTransaction

      public boolean isSubTransaction()
      Determine if this is a sub-transaction to a larger transaction. If true is returned the larger transaction will not complete until all sub-transactions have ended. The larger transaction will rollback upon completion if any of the sub-transactions do not commit.
      Returns:
      true if this is a sub-transaction, else false.

    • abortOnClose

      public void abortOnClose()
      Mark transaction for rollback/non-commit upon closing. A subsequent invocation of commitOnClose() will alter this state prior to closing.

    • commitOnClose

      public void commitOnClose()
      Mark transaction for commit upon closing. This state is assumed by default. A subsequent invocation of abortOnClose() will alter this state prior to closing.

    • abort

      public void abort()
      Mark transaction for rollback/non-commit and end transaction if active.

    • commit

      public void commit()
      Mark transaction for commit and end transaction if active.

    • close

      public void close()
      End this transaction if active using the current commit state. See commitOnClose(), abortOnClose().
      Specified by:
      close in interface AutoCloseable