DbUtils使用

前言

 本文介绍了如何使用apache dbutils。主要以测试代码介绍。本文的代码使用了dbcp，请参见文章：dbutils与dbcp整合

使用代码

1.更新操作（insert、update、delete），使用update方法完成：

　　int update(String sql)int update(String sql, Object... params) 

　　int update(String sql, Object param) 

　　参数：sql：为需要执行的sql语句，

　　　　params为参数

示例：

runner.update("delete from user where userName=?","用户名");
 
int rowEffects = runner.update("insert into user(userName,password,comment) values(?,?,?)", "用户名","密码","备注");

2.查询结果 

dbutils支持返回以下类型的结果：

 　　ArrayHandler ：将结果集中第一行的数据转化成对象数组。返回值类型：Object[]

　　 ArrayListHandler将结果集中所有的数据转化成List。返回值类型：List<Object[]>

 　　BeanHandler ：将Object中第一行的数据转化成类对象。返回值类型：T

 　　BeanListHandler ：将Object中所有的数据转化成List，List中存放的是类对象。返回值类型：List<T>

 　　ColumnListHandler ：将Object中某一列的数据存成List，List中存放的是 Object对象。返回值类型：List<Object>

 　　KeyedHandler ：将Object中存成映射，key为某一列对应为Map。Map中存放的是数据。Map<关键字字段值，map<列名,字段值>>返回值类型：Map<Object,Map<String,Object>>

 　　MapHandler ：将结果集中第一行的数据存成Map<列名,字段值>映射。返回值类型：Map<String,Object>

 　　MapListHandler ：将结果集中所有的数据存成List。List中存放的是Map<列名,字段值>。返回值类型：List<Map<String,Object>>

 　　ScalarHandler ：返回结果集中的第一行的指定列的一个值。返回值类型：Object

//返回ArrayHandler结果,第一行结果：Object[]
System.out.println("返回ArrayHandler结果......");
Object[] arrayResult = runner.query("select * from user", new ArrayHandler());
for (int i = 0; i < arrayResult.length; i++) {
    System.out.print(arrayResult[i] + "    ");
}
System.out.println();
 
 
//返回ArrayListHandler结果,第一行结果：List<Object[]>
System.out.println("返回ArrayListHandler结果.........");
List<Object[]> arrayListResult = runner.query("select * from user", new ArrayListHandler());
for (int i = 0; i < arrayListResult.size(); i++) {
    for (int j = 0; j < arrayListResult.get(i).length; j++) {
        System.out.print(arrayListResult.get(i)[j]+"    ");
    }
    System.out.println();
}
System.out.println();
 
 
//返回bean
User user = runner.query("select * from user where userId=?", 1,new BeanHandler<User>(User.class));
Assert.assertEquals(user.getUserName(), "用户名");
 
 
//返回beanlist
System.out.println("返回BeanList结果......");
List<User> beanListResult = runner.query("select * from user", new BeanListHandler(User.class));
Iterator<User> iter_beanList = beanListResult.iterator();
while(iter_beanList.hasNext()){
    System.out.println(iter_beanList.next().getUserName());
}
 
 
//返回指定列
System.out.println("返回ColumnList结果......");
List<Object> columnResult = runner.query("select * from user",new ColumnListHandler("userName"));
Iterator<Object> iter = columnResult.iterator();
while(iter.hasNext()){
    System.out.println(iter.next());
}
 
 
 
//返回KeyedHandler结果：Map<Object,Map<String,Object>>：map的key为KeyedHandler指定
System.out.println("返回KeyedHandler结果.........");
Map<Object, Map<String, Object>> keyedResult = runner.query("select * from user", new KeyedHandler("userName"));
System.out.println(keyedResult.get("用户名").get("userId"));
 
 
//MapHandler
System.out.println("返回MapHandler结果.........");
Map<String, Object> mapResult = runner.query("select * from user", new MapHandler());
Iterator<String> iter_mapResult = mapResult.keySet().iterator();
while (iter_mapResult.hasNext()) {
    System.out.print(mapResult.get(iter_mapResult.next())+"   ");
}
System.out.println();
 
 
//返回MapListHandler结果
System.out.println("返回MapListHandler结果.........");
List<Map<String,Object>> mapListResult = runner.query("select * from user", new MapListHandler());
for(int i=0;i<mapListResult.size();i++){
    Iterator<String> values = mapListResult.get(i).keySet().iterator();
    while(values.hasNext()){
        System.out.print(mapListResult.get(i).get(values.next())+"   ");
    }
    System.out.println();
}
 
Object increaseId=runner.query("select last_insert_id()", new ScalarHandler());
System.out.println(increaseId);

附：其他代码

数据库代码

DROP TABLE IF EXISTS `user`;
CREATE TABLE `user` (
  `comment` varchar(250) DEFAULT NULL,
  `password` varchar(20) DEFAULT NULL,
  `userName` varchar(20) NOT NULL,
  `userId` int(11) NOT NULL AUTO_INCREMENT,
  PRIMARY KEY (`userId`)
) ENGINE=InnoDB AUTO_INCREMENT=18 DEFAULT CHARSET=utf8;
INSERT INTO `user` VALUES ('备注', '密码', '用户名', '1');
INSERT INTO `user` VALUES ('备注2', '密码2', '用户名2', '7');

User.java

package com.dbutils.model;
 
public class User {
    private int userId;
    private String userName;
    private String password;
    private String comment;
     
    public int getUserId() {
        return userId;
    }
    public void setUserId(int userId) {
        this.userId = userId;
    }
    public String getUserName() {
        return userName;
    }
    public void setUserName(String userName) {
        this.userName = userName;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    public String getComment() {
        return comment;
    }
    public void setComment(String comment) {
        this.comment = comment;
    }
}

DbHelper.java

package com.dbutils.common;
 
import javax.sql.DataSource;
 
import org.apache.commons.dbcp.BasicDataSource;
import org.apache.commons.dbutils.QueryRunner;
 
public class DbHelper {
    private static DataSource dataSource;
    private DbHelper(){
    }
     
    public static QueryRunner getQueryRunner(){
        if(DbHelper.dataSource==null){
            //配置dbcp数据源
            BasicDataSource dbcpDataSource = new BasicDataSource();
            dbcpDataSource.setUrl("jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=UTF-8&zeroDateTimeBehavior=convertToNull");
            dbcpDataSource.setDriverClassName("com.mysql.jdbc.Driver");
            dbcpDataSource.setUsername("root");
            dbcpDataSource.setPassword("1234");
            dbcpDataSource.setDefaultAutoCommit(true);
            dbcpDataSource.setMaxActive(100);
            dbcpDataSource.setMaxIdle(30);
            dbcpDataSource.setMaxWait(500);
            DbHelper.dataSource = (DataSource)dbcpDataSource;
            System.out.println("Initialize dbcp...");
        }
        return new QueryRunner(DbHelper.dataSource);
    }
}