java手写jdbc连接池

青旅半醒 2021-09-29 14:46 411阅读 0赞

废话不多说，直接上代码。

public class ConnectionUtil {
    
    	private static final Logger logger = LoggerFactory.getLogger(ConnectionUtil.class);
    	private static final  List<Connection> pool = new  ArrayList<>();
    	private static final int POOL_COUNT = 5;
    	private static String url = null;
    	private static String userName = null ;
    	private static String passWord = null ;
    	private ConnectionUtil(){}
    	
    	/**
    	 * 初始化连接数大小
    	 */
    	static{
    		  try {
    			url = "连接串";
    			userName = "用户名";
    			passWord = "密码";
    			Class.forName("net.sf.log4jdbc.DriverSpy");
    			Connection conn = null;
    			for (int i = 0; i < POOL_COUNT; i++) {
    				conn = DriverManager.getConnection(url,userName ,passWord);
    				pool.add(conn);
    			}
    		} catch (Exception e) {
    			logger.error("初始化连接失败",e);
    		}
    	}
    	
    	/**
    	 * 添加一个连接到池子中,应该考虑最大上限
    	 * @param conn
    	 */
    	private static void add(Connection conn){
    		if(conn != null){
    			pool.add(conn);
    		}
    	}
    	
    	/**
    	 * 移除一个连接
    	 * @param conn
    	 */
    	private static void remove(Connection conn){
    		pool.remove(conn);
    	}
    	
    	/**
    	 * 获取一个连接,当连接池中的不够用时，新建一个
    	 */
    	public  static Connection get() throws ClassNotFoundException, SQLException{
    		Connection conn = null; 
    		if(!pool.isEmpty()){
    			conn = pool.get(0);
    			remove(conn);
    		 }else{
    			 conn = getConnection();
    			 add(conn);
    		 }
    		 return conn;
    	}
    	
    	/**
    	 * 使用完毕之后，再放回池子中
    	 * @return
    	 */
    	public static void backConn(Connection conn){
    		add(conn);
    	}
    	
    	/**
    	 * 新建一个连接
    	 * @return
    	 */
    	private static Connection getConnection() throws ClassNotFoundException, SQLException{
    		Class.forName("net.sf.log4jdbc.DriverSpy");
    		return DriverManager.getConnection(url,userName ,passWord);
    	}