数据库连接dbcp$c3p0

<?xml version="1.0" encoding="UTF-8"?>

<c3p0-config>

<default-config name="hoobey">

<property name="jdbcUrl">jdbc:mysql://localhost:3306/mydb1</property>

<property name="driverClass">com.mysql.jdbc.Driver</property>

</default-config>

</c3p0-config>

package cn.itcast.demo1;

import java.beans.PropertyVetoException;

import java.sql.Connection;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.sql.Statement;

import org.junit.Test;

import com.mchange.v2.c3p0.ComboPooledDataSource;

/**

* c3p0

* @author cxf

public class c3p0 {

/**

* 代码配置

* @throws PropertyVetoException

* @throws SQLException

@Test

public void fun1() throws PropertyVetoException, SQLException {

// 创建连接池对象

ComboPooledDataSource dataSource = new ComboPooledDataSource();

// 对池进行四大参数的配置

dataSource.setDriverClass("com.mysql.jdbc.Driver");

dataSource.setJdbcUrl("jdbc:mysql://localhost:3306/mydb1");

dataSource.setUser("root");

dataSource.setPassword("123456");

// 池配置

dataSource.setAcquireIncrement(5);

dataSource.setInitialPoolSize(20);

dataSource.setMinPoolSize(2);

dataSource.setMaxPoolSize(50);

Connection con = dataSource.getConnection();

String sql = "select * from products";

Statement stmt = con.createStatement();

ResultSet rs = (ResultSet) stmt.executeQuery(sql);

int count = rs.getMetaData().getColumnCount();

while(rs.next()){

for(int i=1; i<=count; i++){

System.out.println(rs.getString(i));

if(i<count){

System.out.println(",");

}

rs.close();

stmt.close();

con.close();

}

/**

* 配置文件的默认配置

* @throws SQLException

@Test

public void fun2() throws SQLException{

/**

* 在创建连接池对象时，这个对象就会自动加载配置文件！不用我们来指定

ComboPooledDataSource dataSource = new ComboPooledDataSource();

Connection con = dataSource.getConnection();

System.out.println(con);

String sql = "select * from products";

Statement stmt = con.createStatement();

ResultSet rs = (ResultSet) stmt.executeQuery(sql);

int count = rs.getMetaData().getColumnCount();

while(rs.next()){

for(int i=1; i<=count; i++){

System.out.println(rs.getString(i));

if(i<count){

System.out.println(",");

}

rs.close();

stmt.close();

con.close();

}

/**

* 使用命名配置信息

* @throws SQLException

@Test

public void fun3() throws SQLException{

/**

* 构造器的参数指定命名配置元素的名称！

* <named-config name="oracle-config">

ComboPooledDataSource dataSource = new ComboPooledDataSource("hoobey");

Connection con = dataSource.getConnection();

System.out.println(con.getClass().getName());

con.close();

}

package cn.itcast.demo1;

import java.beans.PropertyVetoException;

import java.sql.Connection;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.sql.Statement;

import org.apache.commons.dbcp.BasicDataSource;

import org.junit.Test;

/**

* c3p0

* @author cxf

public class dbcp {

/**

* 代码配置

* @throws PropertyVetoException

* @throws SQLException

@Test

* dbcp连接池 commons-dbcp-1.4.jar commons-pool-1.3.jar

public void fun1() throws PropertyVetoException, SQLException {

// 创建连接池对象

BasicDataSource dataSource = new BasicDataSource();

// 对池进行四大参数的配置

dataSource.setDriverClassName("com.mysql.jdbc.Driver");

dataSource.setUrl("jdbc:mysql://localhost:3306/mydb1");

dataSource.setUsername("root");

dataSource.setPassword("123456");

// 池配置

dataSource.setMaxActive(20);

dataSource.setMinIdle(3);

dataSource.setMaxWait(200);

Connection con = dataSource.getConnection();

System.out.println(con.getClass().getName());

String sql = "select * from products";

Statement stmt = con.createStatement();

ResultSet rs = (ResultSet) stmt.executeQuery(sql);

int count = rs.getMetaData().getColumnCount();

while(rs.next()){

for(int i=1; i<=count; i++){

System.out.println(rs.getString(i));

if(i<count){

System.out.println(",");

}

rs.close();

stmt.close();

con.close();

}

package cn.itcast.jdbc;

import java.sql.Connection;

import java.sql.SQLException;

import javax.sql.DataSource;

import com.mchange.v2.c3p0.ComboPooledDataSource;

public class JdbcUtils {

// 配置文件的默认配置！要求你必须给出c3p0-config.xml！！！

private static ComboPooledDataSource dataSource = new ComboPooledDataSource();

/**

* 使用连接池返回一个连接对象

* @return

* @throws SQLException

public static Connection getConnection() throws SQLException {

return dataSource.getConnection();

}

/**

* 返回连接池对象！

* @return

public static DataSource getDataSource() {

return dataSource;

}

-------------------------------------------------------------------------------------------

public void fun4() throws SQLException{
  System.out.println("---------最简单的获取连接对象的方法---------------------------------------");
  Connection con = JdbcUtil.getConnection();
  String sql = "select * from products";
  Statement stmt = con.createStatement();
  ResultSet rs = (ResultSet) stmt.executeQuery(sql);
  int count = rs.getMetaData().getColumnCount();
  while(rs.next()){
   for(int i=1; i<=count; i++){
    System.out.println(rs.getString(i));
    if(i<count){
     System.out.println(",");
    }
   }
  }
  rs.close();
  stmt.close();
  con.close();
  con.close();
}

来源：https://www.cnblogs.com/hoobey/p/5426576.html

标签

c3p0

resultset