C3P0 与 DBCP连接池使用

Myth丶恋晨 2022-04-18 05:45 271阅读 0赞

一：C3P0

> 使用需要引入jar包，配置c3p0-config.xml

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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:///typ?useUnicode=true&characterEncoding=utf-8</property>
    		<property name="user">root</property>
    		<property name="password">admin</property>
    		<property name="initialPoolSize">5</property>
    		<property name="maxPoolSize">20</property>
    	</default-config>
    
    	<named-config name="ityp">
    		<property name="driverClass">com.mysql.jdbc.Driver</property>
    		<property name="jdbcUrl">jdbc:mysql:///typ?useUnicode=true&characterEncoding=utf-8</property>
    		<property name="user">root</property>
    		<property name="password">admin</property>
    	</named-config>
    
    
    </c3p0-config>

c3p0提供核心工具类，使用连接池必须创建该类的实例对象

package WEB10_JDBC_Utils;
    
    import java.sql.Connection;
    import java.sql.SQLException;
    
    import javax.sql.DataSource;
    
    import com.mchange.v2.c3p0.ComboPooledDataSource;
    
    public class C3P0Utils {
    	private static ComboPooledDataSource dataSource= new ComboPooledDataSource();
    	
    	public static DataSource getDataSource() {
    		return dataSource;
    	}
    	public static Connection getConnection() {
    		try {
    			return dataSource.getConnection();
    		} catch (SQLException e) {
    			throw new RuntimeException();
    		}
    	}
    }

TestC3P0测试类

@Test
    	public void add1() {
    		Connection conn = null;
    		PreparedStatement pstmt= null;
    		try {
    			conn = C3P0Utils.getConnection();
    			String sql = "insert into user1 values(null,?,?)";
    			pstmt = conn.prepareStatement(sql);
    			pstmt.setString(1, "李四");
    			pstmt.setString(2, "123");
    			int row =pstmt.executeUpdate();
    			if(row>0) {
    				System.out.println("yes");
    			}else {
    				System.out.println("no");
    			}
    		} catch (Exception e) {
    			throw new RuntimeException();
    		}
    	}

二：DBCP

需要引入jar包，配置xx.properties

xx.properties

driver=com.mysql.jdbc.Driver
    url=jdbc:mysql://localhost:3306/typ?useUnicode=true&characterEncoding=utf8
    username=root
    password=admin

工具类

package WEB10_JDBC_Utils;
    
    import java.io.InputStream;
    import java.sql.Connection;
    import java.sql.SQLException;
    import java.util.Properties;
    
    import javax.sql.DataSource;
    
    import org.apache.commons.dbcp.BasicDataSourceFactory;
    
    
    public class DBCPUtils {
    	private static DataSource dataSource;
    	static {
    		try {
    			InputStream is = DBCPUtils.class.getClassLoader().getResourceAsStream("db.properties");
    			Properties props = new Properties();
    			props.load(is);
    			dataSource = BasicDataSourceFactory.createDataSource(props);
    		} catch (Exception e) {
    			throw new RuntimeException();
    		}
    	}
    	
    	public static DataSource getDataSource() {
    		return dataSource;
    	}
    	public static Connection getConnection() {
    		try {
    			return dataSource.getConnection();
    		} catch (SQLException e) {
    			throw new RuntimeException();
    		}
    	}
    }

TestDBCP 测试类

package JDBCTest;
    
    import java.sql.Connection;
    import java.sql.PreparedStatement;
    
    import org.junit.Test;
    
    import WEB10_JDBC_Utils.DBCPUtils;
    
    public class DBCPTest {
    	
    	@Test
    	public void add() {
    		Connection conn = null;
    		PreparedStatement pstmt =null;
    		try {
    			conn = DBCPUtils.getConnection();
    			String sql = "insert into user1 values(null,?,?)";
    			pstmt = conn.prepareStatement(sql);
    			pstmt.setString(1, "李虎");
    			pstmt.setString(2, "123");
    			int row =pstmt.executeUpdate();
    			if(row>0) {
    				System.out.println("yes");
    			}else {
    				System.out.println("no");
    			}
    		} catch (Exception e) {
    			throw new RuntimeException();
    		}
    	}
    }

## 相比较而言，DBCP需要加载配置文件 ##

C3P0插入mysql数据库的时候，插入中文，出现 “？？” 问题

c3p0-config.xml

jdbcurl 处：

jdbc:mysql:///typ?useUnicode=true&characterEncoding=utf-8

OK!!

XML文件 & 代表&

[20181109111425735.png]: /images/20220418/eb3229aa500541a1928dc7ac76af460b.png
[20181109111441411.png]: /images/20220418/f4ada19794d7465db27226550a292a5d.png