Connection.rollback method. When a transaction
* is rolled back to a savepoint all changes made after that
* savepoint are undone.
*
* Savepoints can be either named or unnamed. Unnamed savepoints
* are identified by an ID generated by the underlying data source.
* @since 1.4 JDBC 3.0
*
*/
public class SavepointSapDB
implements Savepoint {
private int SavepointId = 0;
private String SavepointName = null;
private boolean released = false;
private static int savepointIndex = 0;
private static final String savepointPrefix_C = "JDBC_SP_";
private com.sap.dbtech.jdbc.InternalStatementSapDB internalStmt = null;
/**
* Creates a new un-named savepoint.
* @since 1.4 JDBC 3.0
*
*/
public SavepointSapDB (ConnectionSapDB conn) throws SQLException{
this.SavepointId = SavepointSapDB.nextSavepointID();
this.internalStmt = new com.sap.dbtech.jdbc.InternalStatementSapDB (conn, com.sap.dbtech.vsp001.SqlMode.Oracle_C);
}
/**
* Creates a new named savepoint.
* @param aSavepointName name of savepoint
* @since 1.4 JDBC 3.0
*
*/
public SavepointSapDB (String aSavepointName, ConnectionSapDB conn) throws SQLException{
this.SavepointName = aSavepointName;
this.internalStmt = new com.sap.dbtech.jdbc.InternalStatementSapDB (conn, com.sap.dbtech.vsp001.SqlMode.Oracle_C);
}
/**
* Retrieves the generated ID for the savepoint that this
* Savepoint object represents.
* @return the numeric ID of this savepoint
* @throws java.sql.SQLException if this is a named savepoint
* @since 1.4 JDBC 3.0
*
*/
public int getSavepointId () throws java.sql.SQLException {
if (this.SavepointId == 0) {
throw new SQLExceptionSapDB(MessageTranslator.translate(MessageKey.ERROR_NAMED_SAVEPOINT));
} else {
return this.SavepointId;
}
}
/**
* Retrieves the name of the savepoint that this Savepoint
* object represents.
* @return the name of this savepoint
* @throws java.sql.SQLException if this is an un-named savepoint
* @since 1.4 JDBC 3.0
*
*/
public String getSavepointName () throws java.sql.SQLException {
if (this.SavepointName == null) {
throw new SQLExceptionSapDB(MessageTranslator.translate(MessageKey.ERROR_UNNAMED_SAVEPOINT));
} else {
return this.SavepointName;
}
}
/**
* Generates a new unique SavepointId
* @return a new unique SavepointId
*/
final static synchronized int nextSavepointID () {
savepointIndex++;
return savepointIndex;
}
/**
* Generates a savepointname from the current savepointid for internal use, because
* the database kernel cannot handle un-named savepoints.
* @return the generated savepointname
*/
final String getInternalSavepointName () {
if (this.SavepointName == null)
return savepointPrefix_C + String.valueOf(this.SavepointId);
else
return this.SavepointName;
}
/**
* Makes a "rollback to savepoint" command and sends it to the database kernel
* @param stmt a valid java.sql.statement
* @throws java.sql.SQLException if a database access error occurs
*/
private void rollbackSavepoint () throws java.sql.SQLException {
this.internalStmt.execute("ROLLBACK TO SAVEPOINT " + this.getInternalSavepointName());
}
/**
* Sets a savepoint in state released
*/
private void releaseSavepoint () throws SQLException {
this.released = true;
if(this.internalStmt.getConnectionSapDB().isReleaseSavePointSupported()) {
try {
this.internalStmt.execute("RELEASE SAVEPOINT " + this.getInternalSavepointName());
} catch(SQLException sqlEx) {
if(sqlEx.getErrorCode() == -3005) {
this.internalStmt.getConnectionSapDB().setReleaseSavePointSupported(false);
} else {
throw sqlEx;
}
}
}
}
/**
* Checks if a savepoint is in state released
* @return true - if savepoint is released and false - if checkpoint isn`t released
*/
private boolean isrelease () {
return this.released;
}
/**
* Creates an unnamed savepoint in the current transaction and
* returns the new Savepoint object that represents it.
* @param conn a ConnectionSapDB object
* @return the new Savepoint object
* @see Savepoint
* @since 1.4
*
*/
public static java.sql.Savepoint setSavepoint (ConnectionSapDB conn) throws java.sql.SQLException {
SavepointSapDB sp = new SavepointSapDB(conn);
sp.internalStmt.execute("SAVEPOINT " + sp.getInternalSavepointName());
return (java.sql.Savepoint)sp;
}
/**
* Creates an unnamed savepoint in the current transaction and
* returns the new Savepoint object that represents it.
* @param SavepointName a savepointname
* @param conn a ConnectionSapDB object
* @return the new Savepoint object
* @see Savepoint
* @since 1.4
*
*/
public static java.sql.Savepoint setSavepoint (String SavepointName, ConnectionSapDB conn) throws java.sql.SQLException {
SavepointSapDB sp = new SavepointSapDB(SavepointName, conn);
sp.internalStmt.execute("SAVEPOINT " + sp.getInternalSavepointName());
return (java.sql.Savepoint)sp;
}
/**
* Undoes all changes made after the given Savepoint object
* was set.
*
* This method should be used only when auto-commit has been disabled.
*
* @param savepoint the Savepoint object to roll back to
* @exception SQLException if a database access error occurs,
* the Savepoint object is no longer valid,
* or this Connection object is currently in
* auto-commit mode
* @see Savepoint
* @see #rollback
* @since 1.4
*/
public static void rollback (java.sql.Savepoint savepoint) throws java.sql.SQLException {
SavepointSapDB sp;
try {
sp = (SavepointSapDB)savepoint;
} catch (ClassCastException classCastEx) {
throw new SQLExceptionSapDB(MessageTranslator.translate(MessageKey.ERROR_NO_SAVEPOINTSAPDB,
savepoint.getClass()));
}
if (sp.isrelease()) {
throw new SQLExceptionSapDB(MessageTranslator.translate(MessageKey.ERROR_SAVEPOINT_RELEASED));
}
sp.rollbackSavepoint();
}
/**
* Removes the given Savepoint object from the current
* transaction. Any reference to the savepoint after it have been removed
* will cause an SQLException to be thrown.
*
* @param savepoint the Savepoint object to be removed
* @exception SQLException if a database access error occurs or
* the given Savepoint object is not a valid
* savepoint in the current transaction
* @since 1.4
*/
public static void releaseSavepoint (java.sql.Savepoint savepoint) throws java.sql.SQLException {
SavepointSapDB sp;
try {
sp = (SavepointSapDB)savepoint;
} catch (java.lang.ClassCastException _exc) {
throw new SQLExceptionSapDB(MessageTranslator.translate(MessageKey.ERROR_NO_SAVEPOINTSAPDB,
savepoint.getClass()));
}
if (sp.isrelease())
throw new SQLExceptionSapDB(MessageTranslator.translate(MessageKey.ERROR_SAVEPOINT_RELEASED));
sp.releaseSavepoint();
}
}