数据库连接池之

数据库连接池之_c3p0

C3p0

　　1,手动设置参数

 1 @Test
 2     public void demo1(){
 3         Connection connection =null;
 4         PreparedStatement preparedStatement=null;
 5         ResultSet resultSet=null;
 6         
 7         try {
 8             //设置数据库的相关信息
 9             ComboPooledDataSource ds=new ComboPooledDataSource();
10             ds.setDriverClass("com.mysql.jdbc.Driver");
11             ds.setJdbcUrl("jdbc:mysql:///day03");
12             ds.setUser("root");
13             ds.setPassword("123");
14             
15             //获取连接
16             connection =ds.getConnection();
17             String sql="select * from Book";
18             preparedStatement=connection .prepareStatement(sql);
19             resultSet=preparedStatement.executeQuery();
20             while(resultSet.next()){
21                 System.out.println(resultSet.getInt("id")+"  "+resultSet.getString("bname"));
22             }
23         } catch (Exception e) {
24             e.printStackTrace();
25         }finally{
26             //这个是一个工具类用来关闭连接
27             JDBCUtils.close(resultSet, preparedStatement, connection);
28         }
29     }

　　2,自动读取配置文件

 1 @Test
 2     public void demo2(){
 3         Connection connection=null;
 4         PreparedStatement ps=null;
 5         ResultSet resultSet=null;
 6         try {
 7             ComboPooledDataSource cs=new ComboPooledDataSource();//可以在这里设置要使用那个数据库
 8             
 9             connection=cs.getConnection();
10             String sql="insert into Book(bname) values(?)";
11             ps=connection.prepareStatement(sql);
12             ps.setString(1,"牧神记");
13             ps.executeUpdate();
14             
15             ps.setString(1,"一念永恒");
16             int num=ps.executeUpdate();
17             if(num>0){
18                 System.out.println("添加成功");
19             }else{
20                 System.out.println("添加失败");
21             }
22         } catch (Exception e) {
23             e.printStackTrace();
24         }finally{
25             JDBCUtils.close(ps, connection);
26         }
27     }

c3p0的配置文件名(c3p0-config.xml)

<?xml version="1.0" encoding="UTF-8"?>
 <c3p0-config> 
     <default-config> 
         <property name="driverClass">com.mysql.jdbc.Driver</property> 
         <property name="jdbcUrl">jdbc:mysql:///day03</property> 
         <property name="user">root</property> 
         <property name="password">123</property> 
         <property name="minPoolSize">5</property> 
         <property name="initialPoolSize">5</property> 
     </default-config>
     
     <named-config name="oracle"> 
          <property name="driverClass">com.mysql.jdbc.Driver</property> 
         <property name="jdbcUrl">jdbc:mysql:///day04</property> 
         <property name="user">root</property> 
         <property name="password">123</property> 
         <property name="minPoolSize">5</property> 
         <property name="initialPoolSize">5</property> 
     </named-config>
</c3p0-config>