java设计模式之享元模式

public class ConnectionPool{

private Vector<Connection> pool ;

private String url="jdbc.mysql://localhost:3306/test";

private String username = "root";

private String password = "root";

private String driverClassName = "com.mysql.jdbc.Driver";

pirvate int poolSize = 100;

private static ConnectionPool instance = null;

Connection conn = null;

private ConnectionPool(){

pool = new Vector<ConnectionPool>(poolSize);

for(int i=0;i<poolSize;i++){

try{

Class.forName(driverClassName);

conn=DriverManager.getConnection(url,username,password);

pool.add(conn);

}catch(ClassNoFoundException e){

e.printStackTrace();

}catch(SQLException e){

e.printStackTrace();

{

}

public synchronized void release(){

pool.add(conn);

}

public synchronized Connection getConnection(){

if(pool.size>0){

Connection conn = pool.get(0);

pool.remove(conn);

return conn;

}else{

return null;

}

}

}

}