JDBC链接数据库版本三，使用C3P0，使用jar文件两个

JdbcUtil类：

package com.xiaohui.jdbc.util;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import javax.sql.DataSource;
import com.mchange.v2.c3p0.ComboPooledDataSource;
public final class JdbcUtil {
    private static ComboPooledDataSource dataSource;
    static {
        dataSource = new ComboPooledDataSource();
    }
    // 取得链接
    public static Connection getMySqlConnection() throws SQLException {
        return dataSource.getConnection();
    }
    //
    public static DataSource getDataSource(){
        return dataSource;
    }

    // 关闭链接
    public static void close(Connection conn) throws SQLException {
        if (conn != null) {
            try {
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
                throw e;
            }
        }
    }

    public static void close(PreparedStatement pstate) throws SQLException {
        if(pstate!=null){
            pstate.close();
        }
    }
    public static void close(ResultSet rs) throws SQLException {
        if(rs!=null){
            rs.close();
        }
    }

}

c3p0-config.xml

<?xml version="1.0" encoding="UTF-8"?>
<c3p0-config>
    <default-config>
        <property name="driverClass">com.mysql.jdbc.Driver</property>
        <property name="user">root</property>
        <property name="password">root</property>
        <property name="jdbcUrl">jdbc:mysql://127.0.0.1:3306/mysql4</property>
    </default-config>
</c3p0-config>

 

分页的一个dao：

package com.xiaohui.cusSys.dao;

import java.sql.SQLException;
import java.util.List;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import org.apache.commons.dbutils.handlers.ScalarHandler;
import com.xiaohui.cusSys.domain.Customer;
import com.xiaohui.cusSys.util.JdbcUtil;

public class Dao {
    private QueryRunner qr = new QueryRunner(JdbcUtil.getDataSource());

    // 根据id返回 Customer 对象
    public Customer getCustomerById(int id) throws SQLException {
        String sql = "select * from customer where id = ?";
        Customer cus = (Customer) qr.query(sql,
                new BeanHandler(Customer.class), id);
        return cus;
    }

    // 分页返回
    public List<Customer> getFyList(int start, int size) throws SQLException {
        List<Customer> list = null;
        String sql = "select * from customer limit ?,?";
        list = qr.query(sql, new BeanListHandler(Customer.class), new Object[] {
                start, size });
        return list;
    }

    // 返回记录的总数目
    public int getAllRecordsCount() throws SQLException {
        String sql = "select count(*) from customer";
        Long temp = qr.query(sql, new ScalarHandler());
        return temp.intValue();
    }

    // 根据ID删除指定的记录
    public void deleteRecordById(int id) throws SQLException {
        String sql = "delete from customer where id = ?";
        qr.update(sql, id);
    }

    // 根据id更新记录信息
    public void updateRecordById(Customer newCus) throws SQLException {
        String sql = "update customer set name= ?,address= ?,tel= ?,mail= ?,birthday= ? where id= ?";
        qr.update(
                sql,
                new Object[] { newCus.getName(), newCus.getAddress(),
                        newCus.getTel(), newCus.getMail(),
                        newCus.getBirthday(), newCus.getId() });
    }

    // 添加记录
    public void addRecord(Customer newCus) throws SQLException {
        String sql = "insert into customer(name,address,tel,mail,birthday) values(?,?,?,?,?)";
        qr.update(sql, new Object[] { newCus.getName(), newCus.getAddress(),
                newCus.getTel(), newCus.getMail(),
                // //将java.util.Date 转换为 java.sql.Date
                // new java.sql.Date( newCus.getBirthday().getTime())
                newCus.getBirthday() });
    }

}

 

jar文件：c3p0-0.9.1.2.jar （关键）  mysql-connector-java-5.1.22-bin.jar（关键） 在dao中 使用到commons-dbutils-1.5.jar

 

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