数据库连接池（没加线程同步）

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package conn;import java.sql.*;import java.util.* ;public class Connpool {List<Connection> live=new ArrayList<Connection>() ;List<Connection> detail=new ArrayList<Connection>() ;public List<Connection> addConn(int i){for(int t=0;t<i;t++){   live.add(this.getConn()) ;}return live ;}public Connection getConn(){Connection conne=null ;try{Class.forName("com.mysql.jdbc.Driver");conne=DriverManager.getConnection("jdbc:mysql://localhost:3306/lring","root","root") ;}catch(Exception e){e.printStackTrace() ;}return conne ;}public void close(Connection conn){this.live.add(conn) ;this.detail.remove(conn) ;} public Connection  ceshi(){Connection ccvt1=this.live.get(0) ;this.detail.add(ccvt1) ;this.live.remove(ccvt1) ;this.close(ccvt1) ;return ccvt1 ;} static public void main(String[] args){ Connpool pool=new Connpool() ; long s1=System.nanoTime() ;  pool.addConn(5) ; long s2=System.nanoTime() ; System.out.println(s2-s1) ; for(int a=0;a<100;a++){ Connection cnn= pool.ceshi() ;System.out.println(cnn.hashCode()) ; System.out.println("执行次数为"+a) ; } }}