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.htmlpublic class TestDBUtils {private static SQLiteDataSource dataSource;private static QueryRunner runner;private static String tableName="User";@BeforeClasspublic 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);    }@Testpublic 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();*/}@Testpublic 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@AfterClasspublic 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 Longprivate 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;}@Overridepublic 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>