DBCP,C3P0,DBUtils笔记

MySQL数据库连接池常用的两种方法
目录结构

  DBCP

    不使用配置文件连接

package com.itheima.dbcp;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import org.apache.commons.dbcp.BasicDataSource;
import org.junit.Test;
import com.itheima.uitl.JDBCUtil;

public class DBCPDemo {
	
	@Test
	public void testDBCP01() {
		Connection conn = null;
		PreparedStatement ps = null;
		try {
			//1.构建数据源对象
			BasicDataSource dataSource = new BasicDataSource();
			//连的是什么类型的数据库，访问的是那个数据库。用户名，密码
			//jdbc:mysql://localhost/bank 主协议：子协议：//本地/数据库名称？url的时区使用中国标准时间。也是就serverTimezone=Asia/Shanghai
			dataSource.setDriverClassName("com.mysql.cj.jdbc.Driver");
			dataSource.setUrl("jdbc:mysql://localhost/bankserverTimezone=Asia/Shanghai");
			dataSource.setUsername("root");
			dataSource.setPassword("123456");
			//2.得到连接对象
			conn = dataSource.getConnection();
			String sql = "insert into account values(null , ? , ?)";
			ps = conn.prepareStatement(sql);
			ps.setString(1, "admin");
			ps.setInt(2, 1000);
			
			ps.executeUpdate();
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally {
			JDBCUtil.release(conn, ps);
		}
	}
}

    使用配置文件连接
        配置文件dbcpconfig.properties（放在了src里面）

#连接设置
driverClassName=com.mysql.cj.jdbc.Driver
url=jdbc:mysql://localhost:3306/bank?serverTimezone=Asia/Shanghai
username=root
password=123456

#<!-- 初始化连接 -->
initialSize=10

#最大连接数量
maxActive=50

#<!-- 最大空闲连接 -->
maxIdle=20

#<!-- 最小空闲连接 -->
minIdle=5

#<!-- 超时等待时间以毫秒为单位 6000毫秒/1000等于60秒 -->
maxWait=60000


#JDBC驱动建立连接时附带的连接属性属性的格式必须为这样：[属性名=property;] 
#注意："user" 与 "password" 两个属性会被明确地传递，因此这里不需要包含他们。
connectionProperties=useUnicode=true;characterEncoding=gbk

#指定由连接池所创建的连接的自动提交（auto-commit）状态。
defaultAutoCommit=true

#driver default 指定由连接池所创建的连接的事务级别（TransactionIsolation）。
#可用值为下列之一：（详情可见javadoc。）NONE,READ_UNCOMMITTED, READ_COMMITTED, REPEATABLE_READ, SERIALIZABLE
defaultTransactionIsolation=READ_UNCOMMITTED

package com.itheima.dbcp;

import java.io.FileInputStream;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.Properties;
import javax.sql.DataSource;
import org.apache.commons.dbcp.BasicDataSource;
import org.apache.commons.dbcp.BasicDataSourceFactory;
import org.junit.Test;
import com.itheima.uitl.JDBCUtil;

public class DBCPDemo02 {
	
	@Test
	public void testDBCP01() {
		Connection conn = null;
		PreparedStatement ps = null;
		try {
			//1.构建数据源对象
			BasicDataSourceFactory factory = new BasicDataSourceFactory();
			Properties properties = new Properties();
//			InputStream is = new FileInputStream("src//dbcpconfig.properties");
			InputStream is = getClass().getClassLoader().getResourceAsStream("dbcpconfig.properties");
			properties.load(is);
			DataSource dataSource =  factory.createDataSource(properties);
			//2.得到连接对象
			conn = dataSource.getConnection();
			String sql = "insert into account values(null , ? , ?)";
			ps = conn.prepareStatement(sql);
			ps.setString(1, "liangchaowei");
			ps.setInt(2, 1000);
			
			ps.executeUpdate();
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally {
			JDBCUtil.release(conn, ps);
		}
	}
}

  DBCP

    不使用配置文件连接

package com.itheima.c3p0;

import java.beans.PropertyVetoException;
import java.sql.Connection;
import java.sql.PreparedStatement;
import org.junit.Test;
import com.itheima.uitl.JDBCUtil;
import com.mchange.v2.c3p0.ComboPooledDataSource;

public class C3P0Demo {
	
	@Test
	public void testC3P0() {
		Connection conn = null;
		PreparedStatement ps = null;
		
		try {
			//1.创建dataSource
			ComboPooledDataSource dataSource = new ComboPooledDataSource();
			dataSource.setDriverClass("com.mysql.cj.jdbc.Driver");
			dataSource.setJdbcUrl("jdbc:mysql://localhost/bank?serverTimezone=Asia/Shanghai");
			dataSource.setUser("root");
			dataSource.setPassword("123456");
			//2.得到连接对象
			conn = dataSource.getConnection();
			String sql = "insert into account values(null , ? , ?)";
			ps = conn.prepareStatement(sql);
			ps.setString(1, "admin5");
			ps.setInt(2, 1000);
			
			ps.executeUpdate();
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally {
			JDBCUtil.release(conn, ps);
		}
		
	}
}

    使用配置文件连接（最常用）
        配置文件c3p0-config.xml（文件名不能改变，开源代码自动找到这个文件，放在了src里面）

<?xml version="1.0" encoding="UTF-8"?>
<c3p0-config>
  <!-- default-config 默认的配置 -->
  <default-config>
    <property name="driverClass">com.mysql.cj.jdbc.Driver</property>
    <property name="jdbcUrl">jdbc:mysql://localhost/bank?serverTimezone=Asia/Shanghai</property>
    <property name="user">root</property>
    <property name="password">123456</property>
    
    
    
    <property name="initialPoolSize">10</property>
    <property name="maxIdleTime">30</property>
    <property name="maxPoolSize">100</property>
    <property name="minPoolSize">10</property>
    <property name="maxStatements">200</property>
  </default-config>
  
  <!-- 下面可以配置其他的数据库的如：Oracle ，在new ComboPooledDataSource("oracle")-->
   <!-- This app is massive! -->
  <!-- <named-config name="intergalactoApp"> --> 
  <named-config name="oracle">
    <property name="acquireIncrement">50</property>
    <property name="initialPoolSize">100</property>
    <property name="minPoolSize">50</property>
    <property name="maxPoolSize">1000</property>

    <!-- intergalactoApp adopts a different approach to configuring statement caching -->
    <property name="maxStatements">0</property> 
    <property name="maxStatementsPerConnection">5</property>

    <!-- he's important, but there's only one of him -->
    <user-overrides user="master-of-the-universe"> 
      <property name="acquireIncrement">1</property>
      <property name="initialPoolSize">1</property>
      <property name="minPoolSize">1</property>
      <property name="maxPoolSize">5</property>
      <property name="maxStatementsPerConnection">50</property>
    </user-overrides>
  </named-config>
</c3p0-config>

package com.itheima.c3p0;

import java.beans.PropertyVetoException;
import java.sql.Connection;
import java.sql.PreparedStatement;
import org.junit.Test;
import com.itheima.uitl.JDBCUtil;
import com.mchange.v2.c3p0.ComboPooledDataSource;

public class C3P0Demo02 {
	
	@Test
	public void testC3P0() {
		Connection conn = null;
		PreparedStatement ps = null;
		
		try {
			//1.创建dataSource 默认会找xml中的default-config分支
			ComboPooledDataSource dataSource = new ComboPooledDataSource();
			
			//2.得到连接对象
			conn = dataSource.getConnection();
			String sql = "insert into account values(null , ? , ?)";
			ps = conn.prepareStatement(sql);
			ps.setString(1, "admin5");
			ps.setInt(2, 1000);
			
			ps.executeUpdate();
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally {
			JDBCUtil.release(conn, ps);
		}
	}
}

  DBUtils

    DBUtils的增删改

package com.itheima.dbutils;

import java.sql.SQLException;
import org.apache.commons.dbutils.QueryRunner;
import org.junit.Test;

import com.mchange.v2.c3p0.ComboPooledDataSource;

public class TestDBUtils {
	
	@Test
	public void testInsert() throws SQLException{
		
		/* ComboPooledDataSource dataSource = new ComboPooledDataSource(); */
		//dbutil只是帮我们简化了CRUD的代码，但是连接的创建以及获取工作，不在他的考虑之内
		QueryRunner queryRunner = new QueryRunner(new ComboPooledDataSource());
		
		//增加
		//queryRunner.update("insert into account values (null , ? , ?)", "aa", 1000);
		
		//删除
		//queryRunner.update("delete from account where id=?", 12);
		
		//修改
		queryRunner.update("update account set money = ? where id = ?", 9999, 5);
	}
}

    DBUtils的查询
###ResultSetHandler 常用的实现类
以下两个是使用频率最高的

BeanHandler,  查询到的单个数据封装成一个对象
BeanListHandler, 查询到的多个数据封装 成一个List<对象>

---

ArrayHandler,  查询到的单个数据封装成一个数组
ArrayListHandler,  查询到的多个数据封装成一个集合 ，集合里面的元素是数组。 



MapHandler,  查询到的单个数据封装成一个map
MapListHandler,查询到的多个数据封装成一个集合 ，集合里面的元素是map。 

ColumnListHandler 查询某个列
KeyedHandler 查询某个值
ScalarHandler 查询那种count()的,函数

package com.itheima.dbutils;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.ResultSetHandler;
import org.apache.commons.dbutils.handlers.BeanHandler;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import org.junit.Test;
import com.itheima.domain.Account;
import com.mchange.v2.c3p0.ComboPooledDataSource;

public class TestDBUtils02 {
	
	@Test
	public void testInsert() throws SQLException{
		
		/* ComboPooledDataSource dataSource = new ComboPooledDataSource(); */
		//dbutil只是帮我们简化了CRUD的代码，但是连接的创建以及获取工作，不在他的考虑之内
		QueryRunner queryRunner = new QueryRunner(new ComboPooledDataSource());
		
		//去执行查询，查询到的数据还是在那个resultset里面，然后调用下面的handle方法，由用户手动去封装。
		/*
		 * Account account = queryRunner.query("select * from account where id = ?", new
		 * ResultSetHandler<Account>(){
		 * 
		 *	 @Override public Account handle(ResultSet rs) throws SQLException { Account
		 * 		account = new Account(); 
		 * 		while(rs.next()) { 
		 * 			String name =rs.getString("name"); 
		 * 			int money = rs.getInt("money");
		 * 
		 * 			account.setName(name); 
		 * 			account.setMoney(money); 
		 * 		} 
		 * 		return account; 
		 * 	}
		 * 
		 * }, 5);
		 * 
		 * System.out.println(account.toString());
		 */
		
		//查询单个
//		Account account = queryRunner.query("select * from account where id = ?", 
//				new BeanHandler<Account>(Account.class), 5);
//		System.out.println(account.toString());
		
		//查询多个
		List<Account> list = queryRunner.query("select * from account", new BeanListHandler<Account>(Account.class));
		
		for (Account account : list) {
			System.out.println(account.toString());
		}
	}
}