You are viewing a plain text version of this content. The canonical link for it is here.
Posted to scm@excalibur.apache.org by le...@apache.org on 2005/04/21 00:21:28 UTC
svn commit: r162085 -
/excalibur/trunk/components/datasource/src/java/org/apache/avalon/excalibur/datasource/AbstractJdbcConnection.java
Author: leif
Date: Wed Apr 20 15:21:26 2005
New Revision: 162085
URL: http://svn.apache.org/viewcvs?rev=162085&view=rev
Log:
Wrap Statements and several other objects in Proxies so that it is now possible to trap exceptions thrown by pretty much any method. This was the next step to my last modification of this class to solve a problem with Oracle where a connection would drop but it would continue to be reused by the pool if it was requested at a higher rate than the ping interval.
Modified:
excalibur/trunk/components/datasource/src/java/org/apache/avalon/excalibur/datasource/AbstractJdbcConnection.java
Modified: excalibur/trunk/components/datasource/src/java/org/apache/avalon/excalibur/datasource/AbstractJdbcConnection.java
URL: http://svn.apache.org/viewcvs/excalibur/trunk/components/datasource/src/java/org/apache/avalon/excalibur/datasource/AbstractJdbcConnection.java?rev=162085&r1=162084&r2=162085&view=diff
==============================================================================
--- excalibur/trunk/components/datasource/src/java/org/apache/avalon/excalibur/datasource/AbstractJdbcConnection.java (original)
+++ excalibur/trunk/components/datasource/src/java/org/apache/avalon/excalibur/datasource/AbstractJdbcConnection.java Wed Apr 20 15:21:26 2005
@@ -21,9 +21,14 @@
import java.lang.reflect.Proxy;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.InvocationTargetException;
+import java.sql.Array;
+import java.sql.CallableStatement;
import java.sql.Connection;
+import java.sql.DatabaseMetaData;
+import java.sql.ParameterMetaData;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
+import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.HashMap;
@@ -413,7 +418,105 @@
throw e.getTargetException();
}
+
+ // See if the return value is an object that needs to be proxied.
+ if ( retVal != null )
+ {
+ // The order of the classes below is important to make sure that all implemented
+ // interfaces are taken into account.
+ if ( retVal instanceof CallableStatement )
+ {
+ retVal = Proxy.newProxyInstance( CallableStatement.class.getClassLoader(),
+ new Class[] { CallableStatement.class }, new ProxiedObject( retVal ) );
+ }
+ else if ( retVal instanceof PreparedStatement )
+ {
+ retVal = Proxy.newProxyInstance( PreparedStatement.class.getClassLoader(),
+ new Class[] { PreparedStatement.class }, new ProxiedObject( retVal ) );
+ }
+ else if ( retVal instanceof Statement )
+ {
+ retVal = Proxy.newProxyInstance( Statement.class.getClassLoader(),
+ new Class[] { Statement.class }, new ProxiedObject( retVal ) );
+ }
+ else if ( retVal instanceof DatabaseMetaData )
+ {
+ retVal = Proxy.newProxyInstance( DatabaseMetaData.class.getClassLoader(),
+ new Class[] { DatabaseMetaData.class }, new ProxiedObject( retVal ) );
+ }
+ else
+ {
+ // Leave the retVal alone and unproxied.
+ }
+ }
return retVal;
+ }
+
+ private class ProxiedObject
+ implements InvocationHandler
+ {
+ Object m_originalObject;
+
+ private ProxiedObject( Object originalObject )
+ {
+ m_originalObject = originalObject;
+ }
+
+ public Object invoke( Object proxy, Method method, Object[] args )
+ throws Throwable
+ {
+ // We want to pass all method calls through to the original object but
+ // we want to catch and make a not of any exceptions thrown along the
+ // way. This is critical to make sure that connections that have gone
+ // bad are not reused without being retested.
+
+ Object retVal;
+ try
+ {
+ retVal = method.invoke( m_originalObject, args );
+ }
+ catch( InvocationTargetException e )
+ {
+ // Remember that an error of some sort was thrown so we can make sure to retest
+ // the connection before it is once again used by a client.
+ m_encounteredError = true;
+
+ throw e.getTargetException();
+ }
+
+ // See if the return value is an object that needs to be proxied.
+ if ( retVal != null )
+ {
+ // The order of the classes below is important to make sure that all implemented
+ // interfaces are taken into account.
+ if ( retVal instanceof Array )
+ {
+ retVal = Proxy.newProxyInstance( Array.class.getClassLoader(),
+ new Class[] { Array.class }, new ProxiedObject( retVal ) );
+ }
+ else if ( retVal instanceof ResultSet )
+ {
+ retVal = Proxy.newProxyInstance( ResultSet.class.getClassLoader(),
+ new Class[] { ResultSet.class }, new ProxiedObject( retVal ) );
+ }
+ else if ( retVal instanceof ResultSetMetaData )
+ {
+ retVal = Proxy.newProxyInstance( ResultSetMetaData.class.getClassLoader(),
+ new Class[] { ResultSetMetaData.class }, new ProxiedObject( retVal ) );
+ }
+ else if ( retVal instanceof ParameterMetaData )
+ {
+ retVal = Proxy.newProxyInstance( ParameterMetaData.class.getClassLoader(),
+ new Class[] { ParameterMetaData.class }, new ProxiedObject( retVal ) );
+ }
+ else
+ {
+ // Leave the retVal alone and unproxied.
+ }
+ }
+
+ return retVal;
+ }
}
}
---------------------------------------------------------------------
To unsubscribe, e-mail: scm-unsubscribe@excalibur.apache.org
For additional commands, e-mail: scm-help@excalibur.apache.org