JDBC C3P0连接池

//Utils

 1 import com.mchange.v2.c3p0.ComboPooledDataSource;
 2 import javax.sql.DataSource;
 3 import java.sql.Connection;
 4 import java.sql.ResultSet;
 5 import java.sql.SQLException;
 6 import java.sql.Statement;
 7 
 8 public class JdbcUtils_C3P0 {
 9     private static DataSource dataSource = null;
10     static {
11         try{
12             dataSource = new ComboPooledDataSource("MYSQL");//配置文件写法
13         }catch (Exception e){
14             e.printStackTrace();
15         }
16     }
17     //获取连接
18     public static Connection getConnection() throws SQLException {
19         return dataSource.getConnection();
20     }
21     //释放资源
22     public  static void release(Connection conn, Statement st, ResultSet rs){
23         if(rs!=null){
24             try{
25                 rs.close();
26             } catch (SQLException e) {
27                 e.printStackTrace();
28             }
29         }
30         if(st!=null){
31             try {
32                 st.close();
33             } catch (SQLException e) {
34                 e.printStackTrace();
35             }
36         }
37         if(conn!=null){
38             try {
39                 conn.close();
40             } catch (SQLException e) {
41                 e.printStackTrace();
42             }
43         }
44 
45     }
46 }

//Test

 1 public class TestC3P0 {
 2     public static void main(String[] args) {
 3         Connection conn = null;
 4         PreparedStatement st = null;
 5         ResultSet rs = null;
 6         try {
 7             conn = JdbcUtils_C3P0.getConnection();
 8 
 9             String sql = "select * from users where id =?";
10 
11             st = conn.prepareStatement(sql);
12 
13             st.setInt(1,1);
14 
15             rs = st.executeQuery();
16 
17             if(rs.next()){
18                 System.out.println(rs.getString("name"));
19             }
20         } catch (SQLException e){
21             e.printStackTrace();
22         }finally {
23             JdbcUtils.release(conn,st,rs);
24         }
25     }
26 
27 }

//C3P0

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <c3p0-config>
 3     <default-config> <!--默认配置 -->
 4         <!--mysql数据库连接的各项参数-->
 5         <property name="driverClass">com.mysql.cj.jdbc.Driver</property>
 6         <property name="jdbcUrl">jdbc:mysql://localhost:3306/jdbcstudy?serverTimezone=GMT%2B8</property>
 7         <property name="user">root</property>
 8         <property name="password">123456789</property>
 9         <!--配置数据库连接池的初始连接数、最小链接数、获取连接数、最大连接数、最大空闲时间-->
10         <property name="initialPoolSize">10</property>
11         <property name="minPoolSize">10</property>
12         <property name="acquireIncrement">5</property>
13         <property name="maxPoolSize">100</property>
14         <property name="maxIdleTime">30</property>
15     </default-config>
16     <!--自定义属性池 -->
17     <name-config name = "MYSQL">
18         <!--mysql数据库连接的各项参数-->
19         <property name="driverClass">com.mysql.cj.jdbc.Driver</property>
20         <property name="jdbcUrl">jdbc:mysql://localhost:3306/jdbcstudy?serverTimezone=GMT%2B8</property>
21         <property name="user">root</property>
22         <property name="password">123456789</property>
23         <!--配置数据库连接池的初始连接数、最小链接数、获取连接数、最大连接数、最大空闲时间-->
24         <property name="initialPoolSize">10</property>
25         <property name="minPoolSize">10</property>
26         <property name="acquireIncrement">5</property>
27         <property name="maxPoolSize">100</property>
28         <property name="maxIdleTime">30</property>
29     </name-config>
30 </c3p0-config>