apache DBUtils 使用例子demo

apache DBUtils是java编程中的数据库操作实用工具，小巧简单实用，

1.对于数据表的读操作，他可以把结果转换成List，Array，Set等java集合，便于程序员操作；

2.对于数据表的写操作，也变得很简单（只需写sql语句）

3.可以使用数据源，使用JNDI， 数据库连接池等技术来优化性能--重用已经构建好的数据库连接对象，而不像php，asp那样，费时费力的不断重复的构建和析构这样的对象。

DBUtils包括3个包：

org.apache.commons.dbutils

org.apache.commons.dbutils.handlers

org.apache.commons.dbutils.wrappers

DBUtils封装了对JDBC的操作，简化了JDBC操作，可以少写代码。

org.apache.commons.dbutils

DbUtils 关闭链接等操作

QueryRunner 进行查询的操作

org.apache.commons.dbutils.handlers

ArrayHandler ：将ResultSet中第一行的数据转化成 对象数组

ArrayListHandler将ResultSet中所有的数据转化成List，List中存放的是Object[]

BeanHandler ：将ResultSet中第一行的数据转化成类对象

BeanListHandler ：将ResultSet中所有的数据转化成List，List中存放的是类对象

ColumnListHandler ：将ResultSet中某一列的数据存成List，List中存放的是Object对象

KeyedHandler ：将ResultSet中存成映射，key为某一列对应为Map。Map中存放的是数据

MapHandler ：将ResultSet中第一行的数据存成Map映射

MapListHandler ：将ResultSet中所有的数据存成List。List中存放的是Map

ScalarHandler ：将ResultSet中一条记录的其中某一列的数据存成Object

org.apache.commons.dbutils.wrappers

SqlNullCheckedResultSet ：对ResultSet进行操作，改版里面的值

StringTrimmedResultSet ：去除ResultSet中中字段的左右空格。Trim()

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

http://commons.apache.org/proper/commons-dbutils/

Queryrunner.query    —————只可以执行select语句。

Queryrunner.update  —————只可以接收update,delte,insert语句

BeanHandler          ——————返回一个 Bean，结果封装到Bean。只查询第一行。适合根据id查询唯一的一行

BeanListHandler     ——————返回List<Bean>所有行，都封装到List，适合于查询多个结果

MapHandler           ——————与BeanHandler应，只返回第一行，封装成Map类型　－　也适合于查询一个结果集的    适合于关联查询，且没有匹配的Bean。

MapListHandler      ——————与BeanListHandler对应，返回所有，封装成List<Map>类型

ScalarHandler        ——————标量- 用于select count(1)|sum|avg|max …一些聚合函数

package com.jiepu.testdbutil;

import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Date;
import java.util.List;
import java.util.Map;

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.apache.commons.dbutils.handlers.MapHandler;
import org.apache.commons.dbutils.handlers.MapListHandler;
import org.apache.commons.dbutils.handlers.ScalarHandler;
import org.junit.AfterClass;
import org.junit.BeforeClass;
import org.junit.Test;
import org.sqlite.SQLiteDataSource;
//http://www.cnblogs.com/liuwt365/p/4111584.html
public class TestDBUtils {
	private static SQLiteDataSource dataSource;
	private static QueryRunner runner;
	private static String tableName="User";
	
	@BeforeClass
	public static  void setUpBeforeClass() throws Exception {
		
		dataSource= new SQLiteDataSource();
		dataSource.setUrl("jdbc:sqlite:testdbutil.db");
		runner=new QueryRunner(dataSource);
		execute("CREATE TABLE IF NOT EXISTS "+tableName+"(id integer primary key autoincrement, name varchar(50),password varchar(50)," +
				"age integer,createdate integer)",dataSource);
		
	}
	public static int execute(String sql ,SQLiteDataSource dataSource){
		Statement statement;
		int result =0;
		try {
			statement = dataSource.getConnection().createStatement();
			result= statement.executeUpdate(sql);
		} catch (SQLException e) {
			e.printStackTrace();
		}
	
		return result;
	}
	
	@Test
    public void Query1() throws Exception
    {
  
        //String sql="INSERT INTO users VALUES ('U002','tom','4321' )";
        //runner.update(sql);
        String sql="INSERT INTO "+tableName+"(name,password,age,createdate) VALUES (?,?,?,?)";
        runner.update(sql,"Jim","123456","24",new Date().getTime());
        runner.update(sql,"Kim","1234567","24",new Date().getTime());
        runner.update(sql,"北京","12345678","24",new Date().getTime());
        runner.update(sql,"嘉兴","123456789","24",new Date().getTime());
        runner.update(sql,"tom","123456789","24",new Date().getTime());
        System.out.println(dataSource);
    }
	@Test
    public void Query2() throws Exception
    {
        //String sql=" UPDATE users SET NAME='Kim' WHERE NAME='jim' ";
        //runner.update(sql);
        String sql=" UPDATE "+tableName+" SET name=? WHERE name=? ";
        runner.update(sql,"lily","Kim");
        Query5();
    }
	@Test
    public void Query3() throws Exception
    {
        //String sql="DELETE FROM users WHERE NAME='lily' ";
        //runner.update(sql);
        String sql="DELETE FROM "+tableName+" WHERE name=? ";
        runner.update(sql,"tom");
        Query5();
    }
	
	@Test
    public void Query4() throws Exception
    {
        //String sql="SELECT * FROM users where id ='U002' ";
        //user u= runner.query(sql, new  BeanHandler<user>(user.class));       
        String sql="SELECT * FROM "+tableName+" where id =? ";
        User u=runner.query(sql, new BeanHandler<User>(User.class),"2");
        System.out.println(u);
    }
	@Test
    public void Query5() throws Exception
    {
        String sql="select * from "+tableName;
        List<User> list= runner.query(sql, new BeanListHandler<User>(User.class));
        for(User u:list)
        {
            System.out.println(u);
        }
    }
	@Test
    public void Query6() throws Exception
    {
        String sql="select id,name,password from "+tableName;
        Map<String, Object> map= runner.query(sql, new MapHandler());
        System.out.println(map.toString());
    }
	@Test
    public void Query7() throws Exception
    {
		String sql="select id,name,password from "+tableName;
        List<Map<String , Object>> list= runner.query(sql, new MapListHandler());
        System.out.println(list);
    }
	@Test
    public void Query8() throws Exception
    {
        String sql="select count(*) from "+tableName;
        Object obj=runner.query(sql, new ScalarHandler());
        int i=Integer.valueOf(obj.toString());
        System.out.println(i);
    }
	@Test
	public void batch()
	{
		 /**String sql="INSERT INTO "+tableName+"(name,password,age,createdate) VALUES (?,?,?,?)";
	     List<User> users=new ArrayList<User>();
	     users.add(new User());
		 runner.batch(sql, users.toArray());
		 Query5();*/	
	}
	@Test
	public void custom() throws SQLException
	{
		ResultSetHandler<User[]> h = new ResultSetHandler<User[]>() {
		    public User[] handle(ResultSet rs) throws SQLException {
		        if (!rs.next()) {
		            return null;
		        }
		    
		        ResultSetMetaData meta = rs.getMetaData();
		        int cols = meta.getColumnCount();
		        User[] result = new User[cols];
		        
		        for (int i = 0; i < cols; i++) {   	
		        	User user=new User();
		        	user.setId(rs.getInt(1));
		        	user.setName(rs.getString(2));
		        	user.setPassword(rs.getString(3));
		        	user.setAge(rs.getLong(4));
		        	user.setCreatedate(rs.getLong(5));	        	
		        	result[i]=user;
		        	rs.next();
		        	
		        }

		        return result;
		    }
		};
		
		User[] result = runner.query("SELECT * FROM "+tableName+" WHERE age=?", h, "24");
		for (User user : result) {
			System.out.println(user);
		}
		
		
		
	}
	//http://wenku.baidu.com/view/6d4bb27602768e9951e73849.html
	@AfterClass
	public static void setUpAfterclass()
	{
		dataSource=null;
		runner=null;
	}

}

package com.jiepu.testdbutil;
public class User {
	//使用dbutil 实体类成员不要使用基本类型int long 应该使用封装类型 Integer Long
	private Integer id;	
	private String name;	
	private String password;
	private Long age;
	private Long createdate;	
	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;
	}
	public String getPassword() {
		return password;
	}
	public void setPassword(String password) {
		this.password = password;
	}
	public Long getAge() {
		return age;
	}
	public void setAge(Long age) {
		this.age = age;
	}
	public Long getCreatedate() {
		return createdate;
	}
	public void setCreatedate(Long createdate) {
		this.createdate = createdate;
	}
	@Override
	public String toString() {
		return "User [id=" + id + ", name=" + name + ", password=" + password
				+ ", age=" + age + ", createdate=" + createdate + "]";
	}
}

maven pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<groupId>com.jiepu</groupId>
	<artifactId>testdbutil</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>jar</packaging>
	<name>testdbutil</name>
	<url>http://maven.apache.org</url>
	<properties>
		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
	</properties>
	<dependencies>
		<dependency>
			<groupId>junit</groupId>
			<artifactId>junit</artifactId>
			<version>4.8.1</version>
		</dependency>
		<dependency>
			<groupId>commons-dbutils</groupId>
			<artifactId>commons-dbutils</artifactId>
			<version>1.6</version>
		</dependency>
		<dependency>
			<groupId>org.xerial</groupId>
			<artifactId>sqlite-jdbc</artifactId>
			<version>3.8.7</version>
		</dependency>
	</dependencies>
</project>