import java.io.PrintWriter;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.LinkedList;
import javax.sql.DataSource;
public class JdbcPool implements DataSource
{
//选用LinkedList方便移除链接
public static LinkedList<Connection> list = new LinkedList<Connection>();static
{
try
{
Class.forName("com.mysql.jdbc.Driver");
//初始化20个链接
for(int i = 0;i<20;i++){
final Connection conn = DriverManager.getConnection("jdbc:mysql:///test","root","root");
//利用jdk动态代理实现增强Connection的close方法
Connection proxy = (Connection) Proxy.newProxyInstance(JdbcPool.class.getClassLoader(),conn.getClass().getInterfaces(),new InvocationHandler(){
public Object invoke(Object obj, Method m, Object[] arg)
throws Throwable
{
if("close".equals(m.getName()))
{
//加到池*其它线程访问
list.addLast(conn);}
return m.invoke(conn,arg);
}
});
list.add(proxy);
}
}
catch (Exception e)
{
e.printStackTrace();
}
}
public PrintWriter getLogWriter() throws SQLException
{
return null;
}
public int getLoginTimeout() throws SQLException
{
// TODO Auto-generated method stub
return 0;
}
public void setLogWriter(PrintWriter arg0) throws SQLException
{
// TODO Auto-generated method stub
}
public void setLoginTimeout(int arg0) throws SQLException
{
// TODO Auto-generated method stub
}
public boolean isWrapperFor(Class<?> arg0) throws SQLException
{
// TODO Auto-generated method stub
return false;
}
public <T> T unwrap(Class<T> arg0) throws SQLException
{
// TODO Auto-generated method stub
return null;
}
public Connection getConnection() throws SQLException
{
if(list.size()<=0)
{
new RuntimeException("数据库忙，稍后再来");
}
//移除第一个引用，不能用get,因为get不能移除引用
return list.removeFirst();}
public Connection getConnection(String arg0, String arg1)
throws SQLException
{
// TODO Auto-generated method stub
return null;
}
}