Common Dbutils组件的使用

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Common Dbutils是操作数据库的组件，对传统操作数据库的类进行二次封装，可以把结果集转化成List。

主要方法：

DbUtils类：启动类

ResultSetHandler接口：转换类型接口

MapListHandler类：实现类，把记录转化成List

BeanListHandler类：实现类，把记录转化成List，使记录为JavaBean类型的对象

Qrery Runner类：执行SQL语句的类

建立三个Java文件

命名为BeanListExample.java

Guestbook.java

MapListExample.java

源码：

BeanListExample.java

Code
package com.sy;

import org.apache.commons.dbutils.DbUtils;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.List;

public class BeanListExample {
    public static void main(String[] args) {
        Connection conn = null;
        String url = "jdbc:mysql://localhost:3306/people";
        String jdbcDriver = "com.mysql.jdbc.Driver";
        String user = "root";
        String password = "hicc";

        DbUtils.loadDriver(jdbcDriver);
        try {
            conn = DriverManager.getConnection(url, user, password);
            QueryRunner qr = new QueryRunner();
            List results = (List) qr.query(conn, "select id,name from guestbook", new BeanListHandler(Guestbook.class));
            for (int i = 0; i < results.size(); i++) {
                Guestbook gb = (Guestbook) results.get(i);
                System.out.println("id:" + gb.getId() + ",name:" + gb.getName());
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            DbUtils.closeQuietly(conn);
        }
    }
}

Guestbook.java

Code
package com.sy;

public class Guestbook {
private Integer id;
private String name;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}

MapListExample.java

Code
package com.sy;

import org.apache.commons.dbutils.DbUtils;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.MapListHandler;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

import java.util.List;
import java.util.Map;

public class MapListExample {
    public static void main(String[] args) {
        Connection conn = null;
        String url = "jdbc:mysql://localhost:3306/people";
        String jdbcDriver = "com.mysql.jdbc.Driver";
        String user = "root";
        String password = "hicc";

        DbUtils.loadDriver(jdbcDriver);
        try {
            conn = DriverManager.getConnection(url, user, password);
            QueryRunner qr = new QueryRunner();
            List results = (List) qr.query(conn, "select id,name from guestmessage", new MapListHandler());
            for (int i = 0; i < results.size(); i++) {
                Map map = (Map) results.get(i);
                System.out.println("id:" + map.get("id") + ",name:" + map.get("name"));
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            DbUtils.closeQuietly(conn);
        }
    }
}

使用组建好需要添加commons-dbutils-1.1.jar和mysql-connector-java-5.1.6-bin.jar两个jar包。