C3P0连接池:
配置文件: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:///mybase</property> <property name="user">root</property> <property name="password">xuyiqing</property> <property name="initialPoolSize">5</property> <property name="maxPoolSize">20</property> </default-config> <named-config name="yiqing"> <property name="driverClass">com.mysql.jdbc.Driver</property> <property name="jdbcUrl">jdbc:mysql:///mybase</property> <property name="user">root</property> <property name="password">xuyiqing</property> </named-config> </c3p0-config>
测试:
数据准备:
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CREATE DATABASE mybase; USE mybase; CREATE TABLE users( uid INT PRIMARY KEY AUTO_INCREMENT, username VARCHAR(64), upassword VARCHAR(64) ); INSERT INTO users (username,upassword) VALUES("zhangsan","123"),("lisi","456"),("wangwu","789"); SELECT * FROM users;
自定义的JDBC工具类:
package demo; import java.io.InputStream; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.util.Properties; public class JDBCUtils3 { public static String driver; public static String url; public static String username; public static String password; static { try { ClassLoader classLoader = JDBCUtils3.class.getClassLoader(); InputStream is = classLoader.getResourceAsStream("db.properties"); Properties props = new Properties(); props.load(is); driver = props.getProperty("driver"); url = props.getProperty("url"); username = props.getProperty("username"); password = props.getProperty("password"); } catch (Exception ex) { ex.printStackTrace(); } } public static Connection getConnection() { Connection conn = null; try { Class.forName(driver); conn = DriverManager.getConnection(url, username, password); } catch (Exception ex) { ex.printStackTrace(); } return conn; } public static void release(Connection conn, PreparedStatement pstmt, ResultSet rs) { if (rs != null) { try { rs.close(); } catch (Exception e) { e.printStackTrace(); } } if (pstmt != null) { try { pstmt.close(); } catch (Exception e) { e.printStackTrace(); } } if (conn != null) { try { conn.close(); } catch (Exception e) { e.printStackTrace(); } } } }
配置文件:
driver=com.mysql.jdbc.Driver url=jdbc:mysql://localhost:3306/mybase username=root password=xuyiqing
测试类:
package demo01; import java.sql.Connection; import java.sql.PreparedStatement; import org.junit.Test; import com.mchange.v2.c3p0.ComboPooledDataSource; import demo.JDBCUtils3; public class TestC3P0 { @Test public void testAddUser1() { Connection conn = null; PreparedStatement pstmt = null; ComboPooledDataSource dataSource = new ComboPooledDataSource();// 默认方式加载 // ComboPooledDataSource dataSource = new ComboPooledDataSource("yiqing"); try { conn = dataSource.getConnection(); String sql = "insert into users values(null,?,?)"; pstmt = conn.prepareStatement(sql); pstmt.setString(1, "张三"); pstmt.setString(2, "123"); int rows = pstmt.executeUpdate(); if (rows > 0) { System.out.println("添加成功!"); } else { System.out.println("添加失败!"); } } catch (Exception e) { throw new RuntimeException(e); } finally { JDBCUtils3.release(conn, pstmt, null); } } }
成功!
可以将C3P0连接池抽取出工具类:
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package demo01; 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(e); } } }
测试:
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package demo01; import java.sql.Connection; import java.sql.PreparedStatement; import org.junit.Test; import demo.JDBCUtils3; public class TestC3P0 { @Test public void testAddUser1() { Connection conn = null; PreparedStatement pstmt = null; try { conn = C3P0Utils.getConnection(); String sql = "insert into users values(null,?,?)"; pstmt = conn.prepareStatement(sql); pstmt.setString(1, "李四"); pstmt.setString(2, "123123"); int rows = pstmt.executeUpdate(); if (rows > 0) { System.out.println("添加成功!"); } else { System.out.println("添加失败!"); } } catch (Exception e) { throw new RuntimeException(e); } finally { JDBCUtils3.release(conn, pstmt, null); } } }
成功!
DBCP连接池:
自定义DBCP工具类:
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package DBCP; 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 { // 1.加载找properties文件输入流 InputStream is = DBCPUtils.class.getClassLoader().getResourceAsStream("db.properties"); // 2.加载输入流 Properties props = new Properties(); props.load(is); // 3.创建数据源 dataSource = BasicDataSourceFactory.createDataSource(props); } catch (Exception e) { throw new RuntimeException(e); } } public static DataSource getDataSource() { return dataSource; } public static Connection getConnection() { try { return dataSource.getConnection(); } catch (SQLException e) { throw new RuntimeException(e); } } }
测试:
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package DBCP; import java.sql.Connection; import java.sql.PreparedStatement; import org.junit.Test; public class TestDBCP { @Test public void testUpdateUserById(){ Connection conn = null; PreparedStatement pstmt = null; try { conn = DBCPUtils.getConnection(); String sql ="update users set upassword=? where uid=?"; pstmt= conn.prepareStatement(sql); pstmt.setString(1, "456789"); pstmt.setInt(2, 1); int rows = pstmt.executeUpdate(); if(rows>0){ System.out.println("更新成功!"); }else{ System.out.println("更新失败!"); } } catch (Exception e) { throw new RuntimeException(e); } } }