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This is the core library for Active Objects. It is generic and can be embedded in any environment. As such it is generic and won't contain all connection pooling, etc.

There is a newer version: 6.1.1

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/*
 * Copyright 2007 Daniel Spiewak
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); 
 * you may not use this file except in compliance with the License. 
 * You may obtain a copy of the License at
 * 
 *	    http://www.apache.org/licenses/LICENSE-2.0 
 * 
 * Unless required by applicable law or agreed to in writing, software 
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package net.java.ao;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.sql.Connection;
import java.sql.SQLException;

import static com.google.common.base.Preconditions.checkNotNull;

final class DelegateConnectionHandler implements InvocationHandler {
    private final Connection delegate;
    private boolean closeable;

    private DelegateConnectionHandler(Connection delegate) {
        this.delegate = checkNotNull(delegate);
        this.closeable = true;
    }

    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        if (isSetCloseableMethod(method)) {
            setCloseable((Boolean) args[0]);
            return Void.TYPE;
        }

        if (isIsCloseableMethod(method)) {
            return isCloseable();
        }


        if (isCloseMethod(method)) {
            close();
            return Void.TYPE;
        } else if (isIsClosedMethod(method)) {
            return isClosed();
        }

        return delegate(method, args);
    }

    private void setCloseable(boolean closeable) {
        this.closeable = closeable;
    }

    private boolean isCloseable() {
        return closeable;
    }

    private void close() throws SQLException {
        if (isCloseable()) {
            delegate.close();
        }
    }

    private boolean isClosed() throws SQLException {
        return delegate.isClosed();
    }

    private Object delegate(Method method, Object[] args) throws NoSuchMethodException, IllegalAccessException, Throwable {
        final Method m = delegate.getClass().getMethod(method.getName(), method.getParameterTypes());
        m.setAccessible(true);
        try {
            return m.invoke(delegate, args);
        } catch (InvocationTargetException e) {
            throw e.getCause();
        }
    }

    public static DelegateConnection newInstance(Connection c) {
        return (DelegateConnection) Proxy.newProxyInstance(
                DelegateConnectionHandler.class.getClassLoader(),
                new Class[]{DelegateConnection.class},
                new DelegateConnectionHandler(c));
    }

    private static boolean isSetCloseableMethod(Method method) {
        return method.getName().equals("setCloseable")
                && method.getParameterTypes().length == 1
                && method.getParameterTypes()[0].equals(boolean.class);
    }


    private static boolean isIsCloseableMethod(Method method) {
        return method.getName().equals("isCloseable")
                && method.getParameterTypes().length == 0;
    }

    private static boolean isCloseMethod(Method method) {
        return method.getName().equals("close")
                && method.getParameterTypes().length == 0;
    }

    private static boolean isIsClosedMethod(Method method) {
        return method.getName().equals("isClosed")
                && method.getParameterTypes().length == 0;
    }
}