jdbcproxygenerator.java

c3p0数据库连接池实现源码

/*
 * Distributed as part of c3p0 v.0.9.1-pre6
 *
 * Copyright (C) 2005 Machinery For Change, Inc.
 *
 * Author: Steve Waldman <[e-mail]>
 *
 * This library is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License version 2.1, as 
 * published by the Free Software Foundation.
 *
 * This software is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this software; see the file LICENSE.  If not, write to the
 * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
 * Boston, MA 02111-1307, USA.
 */


package com.mchange.v2.c3p0.codegen;

import java.io.*;
import java.lang.reflect.*;
import java.sql.*;
import com.mchange.v2.codegen.*;
import com.mchange.v2.codegen.intfc.*;
import com.mchange.v2.c3p0.C3P0ProxyConnection;
import com.mchange.v2.c3p0.C3P0ProxyStatement;

public abstract class JdbcProxyGenerator extends DelegatorGenerator
{
    final static boolean PREMATURE_DETACH_DEBUG = false;

    JdbcProxyGenerator()
    {
	this.setGenerateInnerSetter( false );
	this.setGenerateInnerGetter( false );
	this.setGenerateNoArgConstructor( false );
	this.setGenerateWrappingConstructor( true );
	this.setClassModifiers( Modifier.PUBLIC | Modifier.FINAL );
	this.setMethodModifiers( Modifier.PUBLIC | Modifier.FINAL );
    }

    abstract String getInnerTypeName();

    static final class NewProxyMetaDataGenerator extends JdbcProxyGenerator
    { 
	String getInnerTypeName()
	{ return "DatabaseMetaData"; }

	protected void generateDelegateCode( Class intfcl, String genclass, Method method, IndentedWriter iw ) throws IOException 
	{
	    String mname   = method.getName();
	    Class  retType = method.getReturnType();
	    
	    if ( ResultSet.class.isAssignableFrom( retType ) )
		{
		    iw.println("ResultSet innerResultSet = inner." + CodegenUtils.methodCall( method ) + ";");
		    iw.println("if (innerResultSet == null) return null;");
		    iw.println("return new NewProxyResultSet( innerResultSet, parentPooledConnection, inner, this );"); 
		}
 	    else if ( mname.equals( "getConnection" ) )
 		{
		    iw.println("return this.proxyCon;");
 		}
	    else
		super.generateDelegateCode( intfcl, genclass, method, iw );
	}

	protected void generatePreDelegateCode( Class intfcl, String genclass, Method method, IndentedWriter iw ) throws IOException 
	{
	    if ( method.getExceptionTypes().length > 0 )
		super.generatePreDelegateCode( intfcl, genclass, method, iw );
	}
	
	protected void generatePostDelegateCode( Class intfcl, String genclass, Method method, IndentedWriter iw ) throws IOException 
	{
	    if ( method.getExceptionTypes().length > 0 )
		super.generatePostDelegateCode( intfcl, genclass, method, iw );
	}

	protected void generateExtraDeclarations( Class intfcl, String genclass, IndentedWriter iw ) throws IOException
	{
	    super.generateExtraDeclarations( intfcl, genclass, iw );
	    iw.println();
	    iw.println("NewProxyConnection proxyCon;");
	    iw.println();
	    iw.print( CodegenUtils.fqcnLastElement( genclass ) );
	    iw.println("( " + CodegenUtils.simpleClassName( intfcl ) + " inner, NewPooledConnection parentPooledConnection, NewProxyConnection proxyCon )");
	    iw.println("{");
	    iw.upIndent();
	    iw.println("this( inner, parentPooledConnection );");
	    iw.println("this.proxyCon = proxyCon;");
	    iw.downIndent();
	    iw.println("}");
	}
    }

    static final class NewProxyResultSetGenerator extends JdbcProxyGenerator
    {
	String getInnerTypeName()
	{ return "ResultSet"; }

	protected void generateDelegateCode( Class intfcl, String genclass, Method method, IndentedWriter iw ) throws IOException 
	{
	    iw.println("if (proxyConn != null) proxyConn.maybeDirtyTransaction();");
	    iw.println();
	    String mname   = method.getName();
	    Class  retType = method.getReturnType();

	    if ( mname.equals("close") )
		{
		    iw.println("if (! this.isDetached())");
		    iw.println("{");
		    iw.upIndent();

		    iw.println("if (creator instanceof Statement)");
		    iw.upIndent();
 		    iw.println("parentPooledConnection.markInactiveResultSetForStatement( (Statement) creator, inner );");
		    iw.downIndent();
		    iw.println("else if (creator instanceof DatabaseMetaData)");
		    iw.upIndent();
 		    iw.println("parentPooledConnection.markInactiveMetaDataResultSet( inner );");
		    iw.downIndent();
		    iw.println("else if (creator instanceof Connection)");
		    iw.upIndent();
 		    iw.println("parentPooledConnection.markInactiveRawConnectionResultSet( inner );");
		    iw.downIndent();
		    iw.println("else throw new InternalError(\042Must be Statement or DatabaseMetaData -- Bad Creator: \042 + creator);");
 
		    iw.println("this.detach();");
		    iw.println("inner.close();");
		    iw.println("this.inner = null;");

		    iw.downIndent();
		    iw.println("}");
		}
	    else if ( mname.equals("getStatement") )
		{
		    iw.println("if (creator instanceof Statement)");
		    iw.upIndent();
 		    iw.println("return (Statement) creatorProxy;");
		    iw.downIndent();
		    iw.println("else if (creator instanceof DatabaseMetaData)");
		    iw.upIndent();
 		    iw.println("return null;");
		    iw.downIndent();
		    iw.println("else throw new InternalError(\042Must be Statement or DatabaseMetaData -- Bad Creator: \042 + creator);");
		}
	    else if ( mname.equals("isClosed") )
		{
		    iw.println( "return this.isDetached();" );
		}
	    else
		super.generateDelegateCode( intfcl, genclass, method, iw );
	}

	protected void generateExtraDeclarations( Class intfcl, String genclass, IndentedWriter iw ) throws IOException
	{
	    super.generateExtraDeclarations( intfcl, genclass, iw );
	    iw.println();
	    iw.println("Object creator;");
	    iw.println("Object creatorProxy;");
	    iw.println("NewProxyConnection proxyConn;");
	    iw.println();
	    iw.print( CodegenUtils.fqcnLastElement( genclass ) );
	    iw.println("( " + CodegenUtils.simpleClassName( intfcl ) + " inner, NewPooledConnection parentPooledConnection, Object c, Object cProxy )");
	    iw.println("{");
	    iw.upIndent();
	    iw.println("this( inner, parentPooledConnection );");
	    iw.println("this.creator      = c;");
	    iw.println("this.creatorProxy = cProxy;");
	    iw.println("if (creatorProxy instanceof NewProxyConnection) this.proxyConn = (NewProxyConnection) cProxy;");
	    iw.downIndent();
	    iw.println("}");
	}

	protected void generatePreDelegateCode( Class intfcl, String genclass, Method method, IndentedWriter iw ) throws IOException 
	{
	    super.generatePreDelegateCode( intfcl, genclass, method, iw );
	}
    }

    static final class NewProxyAnyStatementGenerator extends JdbcProxyGenerator
    {
	String getInnerTypeName()
	{ return "Statement"; }

	private final static boolean CONCURRENT_ACCESS_DEBUG = false;

	{
	    this.setExtraInterfaces( new Class[] { C3P0ProxyStatement.class } );
	}

	protected void generateDelegateCode( Class intfcl, String genclass, Method method, IndentedWriter iw ) throws IOException 
	{
	    iw.println("maybeDirtyTransaction();");
	    iw.println();

	    String mname   = method.getName();
	    Class  retType = method.getReturnType();

	    if ( ResultSet.class.isAssignableFrom( retType ) )
		{
		    iw.println("ResultSet innerResultSet = inner." + CodegenUtils.methodCall( method ) + ";");
		    iw.println("if (innerResultSet == null) return null;");
		    iw.println("parentPooledConnection.markActiveResultSetForStatement( inner, innerResultSet );");
		    iw.println("return new NewProxyResultSet( innerResultSet, parentPooledConnection, inner, this );"); 
		}
	    else if ( mname.equals("getConnection") )
		{
 		    iw.println("if (! this.isDetached())");
 		    iw.upIndent();
		    iw.println("return creatorProxy;");
 		    iw.downIndent();
 		    iw.println("else");
 		    iw.upIndent();
 		    iw.println("throw new SQLException(\"You cannot operate on a closed Statement!\");");
 		    iw.downIndent();
		}
	    else if ( mname.equals("close") )
		{
		    iw.println("if (! this.isDetached())");
		    iw.println("{");
		    iw.upIndent();
		    
		    iw.println("if ( is_cached )");
		    iw.upIndent();
		    iw.println("parentPooledConnection.checkinStatement( inner );");
		    iw.downIndent();
		    iw.println("else");
		    iw.println("{");
		    iw.upIndent();
		    iw.println("parentPooledConnection.markInactiveUncachedStatement( inner );");

		    iw.println("try{ inner.close(); }");
		    iw.println("catch (Exception e )");
		    iw.println("{");
		    iw.upIndent();

		    iw.println("if (logger.isLoggable( MLevel.WARNING ))");
		    iw.upIndent();
		    iw.println("logger.log( MLevel.WARNING, \042Exception on close of inner statement.\042, e);");
		    iw.downIndent();

		    iw.println( "SQLException sqle = SqlUtils.toSQLException( e );" );
		    iw.println( "throw sqle;" );
		    iw.downIndent();
		    iw.println("}");
		    iw.downIndent();
		    iw.println("}");

		    iw.println();
		    iw.println("this.detach();");
		    iw.println("this.inner = null;");
		    iw.println("this.creatorProxy = null;");

		    iw.downIndent();
		    iw.println("}");
		}
	    else if ( mname.equals("isClosed") )
		{
		    iw.println( "return this.isDetached();" );
		}
	    else
		super.generateDelegateCode( intfcl, genclass, method, iw );
	}

	protected void generatePreDelegateCode( Class intfcl, String genclass, Method method, IndentedWriter iw ) throws IOException 
	{
	    // concurrent-access-debug only
	    if (CONCURRENT_ACCESS_DEBUG)
		{
		    iw.println("Object record;");
		    iw.println("synchronized (concurrentAccessRecorder)");
		    iw.println("{");
		    iw.upIndent();

		    iw.println("record = concurrentAccessRecorder.record();");
		    iw.println("int num_concurrent_clients = concurrentAccessRecorder.size();");
		    iw.println("if (num_concurrent_clients != 1)");
		    iw.upIndent();
		    iw.println("logger.log(MLevel.WARNING, " +
			       "concurrentAccessRecorder.getDump(\042Apparent concurrent access! (\042 + num_concurrent_clients + \042 clients.\042) );");
		    iw.downIndent();
		    iw.downIndent();
		    iw.println("}");
		    iw.println();
		}
	    // end concurrent-access-debug only

	    super.generatePreDelegateCode( intfcl, genclass, method, iw );
	}
    
	protected void generatePostDelegateCode( Class intfcl, String genclass, Method method, IndentedWriter iw ) throws IOException 
	{
	    super.generatePostDelegateCode( intfcl, genclass, method, iw );

	    // concurrent-access-debug only
	    if (CONCURRENT_ACCESS_DEBUG)
		{
		    iw.println("finally");
		    iw.println("{");
		    iw.upIndent();
		    iw.println("concurrentAccessRecorder.remove( record );");
		    iw.downIndent();
		    iw.println("}");
		}
	    // end concurrent-access-debug only
	}

	protected void generateExtraDeclarations( Class intfcl, String genclass, IndentedWriter iw ) throws IOException
	{