[javaEE] 开源数据库连接池详解编程语言

import java.io.FileReader; 
import java.sql.Connection; 
import java.sql.ResultSet; 
import java.sql.Statement; 
import java.util.Properties; 
 
import javax.sql.DataSource; 
 
import org.apache.commons.dbcp.BasicDataSourceFactory; 
 
public class DBCPTest { 
    public static void main(String[] args) throws Exception { 
        //导入配置文件 
        Properties prop=new Properties(); 
        prop.load(new FileReader("dbcp.properties")); 
        //获取数据源 
        BasicDataSourceFactory factory=new BasicDataSourceFactory(); 
        DataSource pool=factory.createDataSource(prop); 
         
        Connection conn=pool.getConnection(); 
        //获取传输器对象 
        Statement statement=conn.createStatement(); 
        //获取结果集对象 
        ResultSet resultSet=statement.executeQuery("select * from user"); 
        //遍历 
        while(resultSet.next()){ 
            String username=resultSet.getString("username"); 
            System.out.println(username); 
        } 
        //关闭资源 
        resultSet.close(); 
        statement.close(); 
        conn.close(); 
         
    } 
}

driverClassName=com.mysql.jdbc.Driver 
url=jdbc:mysql:///java 
username=root 
password=root

import java.sql.Connection; 
import java.sql.ResultSet; 
import java.sql.Statement; 
 
import com.mchange.v2.c3p0.ComboPooledDataSource; 
 
public class DBCPTest { 
    public static void main(String[] args) throws Exception { 
        //使用C3P0 
        ComboPooledDataSource pool=new ComboPooledDataSource(); 
        Connection conn=pool.getConnection(); 
        //获取传输器对象 
        Statement statement=conn.createStatement(); 
        //获取结果集对象 
        ResultSet resultSet=statement.executeQuery("select * from user"); 
        //遍历 
        while(resultSet.next()){ 
            String username=resultSet.getString("username"); 
            System.out.println(username); 
        } 
        //关闭资源 
        resultSet.close(); 
        statement.close(); 
        conn.close(); 
         
    } 
}

<?xml version="1.0" encoding="utf-8"?> 
<c3p0-config> 
    <default-config> 
        <property name="driverClass">com.mysql.jdbc.Driver</property> 
        <property name="jdbcUrl">jdbc:mysql:///java</property> 
        <property name="user">root</property> 
        <property name="password">root</property> 
    </default-config> 
</c3p0-config>