连接池得例子得小问题

import java.net.Socket;
import java.util.Hashtable;public class ConnectionPool
{
private static final int CONNECTION_POOL_SIZE=10;
private static final String API_SERVER_HOST="127.0.0.01";
private static final int API_SERVER_PORT=80;

private static ConnectionPool self=null;

private Hashtable socketPool=null;//连接池
private boolean[] socketStatusArray=null;//连接得状态 true被占用false空闲

public static synchronized void init()
{
self=new ConnectionPool();
self.socketPool=new Hashtable();
self.socketStatusArray=new boolean[CONNECTION_POOL_SIZE];

//初始化连接池
self.buildConnectionPool();
}
 
 public static synchronized void reset()
 {
  self=null;
  init();
}

public static Socket getConnection()
{
if(self==null)
 init();
 
 int i=0;
 for(i=0;i<CONNECTION_POOL_SIZE;i++)
 {
  if(!self.socketStatusArray[i])
  {
  self.socketStatusArray[i]=true;
  break;
  }
}
if(i<CONNECTION_POOL_SIZE)
  return (Socket)self.socketPool.get(new Integer(i));
else
{
System.out.println("从连接池种获取与邮局得连接失败，已经没有空闲连接！");

throw new RuntimeException("No enough pooled connection.");
}
}

public static void releaseConnection(Socket Socket)
{
if(self==null)
init();

for(int i=0;i<CONNECTION_POOL_SIZE;i++)
{
if(((Socket)self.socketPool.get(new Integer(i)))==Socket)
{
self.socketStatusArray[i]=false;
break;
}
}
}

public static Socket rebuildConnection(Socket Socket)
{
if(self==null)
init();

Socket newSocket=null;
for(int i=0;i<CONNECTION_POOL_SIZE;i++)
{
try
{
if(((Socket)self.socketPool.get(new Integer(i)))==Socket)
{
System.out.println("重建连接池中得第"+i+"个连接.");
newSocket=new Socket(API_SERVER_HOST,API_SERVER_PORT);
self.socketPool.put(new Integer(i),newSocket);
self.socketStatusArray[i]=true;
break;
}
}
catch(Exception e)
{
System.out.println("重建连接失败!");
throw new RuntimeException(e);
}
}
return newSocket;
}
public synchronized static void buildConnectionPool()
{
if(self==null)
init();

System.out.println("准备建立连接池.");
Socket Socket=null;
try
{
for(int i=0;i<CONNECTION_POOL_SIZE;i++)
{
Socket=new Socket(API_SERVER_HOST,API_SERVER_PORT);
self.socketPool.put(new Integer(i),Socket);
self.socketStatusArray[i]=false;
}
}
catch(Exception e)
{
System.out.println("与邮局得连接池建立失败!");
throw new RuntimeException(e);
}
}

public synchronized static void releaseAllConnection()
{
if(self==null)
init();

//关闭所有连接
Socket Socket=null;
for(int i=0;i<CONNECTION_POOL_SIZE;i++)
{
Socket=(Socket)self.socketPool.get(new Integer(i));
try
{
Socket.close();
}
catch(Exception e)
{}
}
}
}
javac 编译提示
注意：ConnectionPool.java使用了未经检查或不安全得操作
用javac -Xlint:unchecked 编译提示
84行：警告：对作为普通类型java.util.Hashtable的成员的put(K,V)得调用未经检查
self.socketPool.put(new Integer(i),newSocket);
109行：同样得错误不明白这个什么意思.