Apache—DBUtils框架

一、什么是dbutils

commons-dbutils 是 Apache 组织提供的一个开源 JDBC工具类库，它是对JDBC的简单封装，学习成本极低，并且使用dbutils能极大简化jdbc编码的工作量，同时也不会影响程序的性能。因此dbutils成为很多不喜欢hibernate的公司的首选。

 

二、dbutils核心API

1、QueryRunner类

 

使用QueryRunner实现增删改查

package com.dbutils;  2 
import java.sql.SQLException;  4 import java.util.Date;  5 import java.util.List;  6 
import org.apache.commons.dbutils.QueryRunner;  8 import org.apache.commons.dbutils.handlers.BeanHandler;  9 import org.apache.commons.dbutils.handlers.BeanListHandler; 10 import org.junit.Test; 11 
import com.domain.User; 13 import com.utils.JdbcUtils; 14 
/**
 * 17  * 使用dbutils完成数据库的增删改查 18  * 19  */
public class Demo1 { 21     // 插入
 @Test 23     public void insert() throws SQLException { 24         QueryRunner runner = new QueryRunner(JdbcUtils.getDataSource()); 25         String sql = "insert into users(id,name,password,email,birthday) values(?,?,?,?,?)"; 26         Object params[] = { 1, "aa", "123", "[e-mail]", new Date() }; 27  runner.update(sql, params); 28  } 29 
    // 删除
 @Test 32     public void delete() throws SQLException { 33         QueryRunner runner = new QueryRunner(JdbcUtils.getDataSource()); 34         String sql = "delete from users where id=?"; 35         runner.update(sql, 2); 36  } 37 
    // 修改
 @Test 40     public void update() throws SQLException { 41         QueryRunner runner = new QueryRunner(JdbcUtils.getDataSource()); 42         String sql = "update users set email=? where id=?"; 43         Object params[] = { "[e-mail]", 2 }; 44  runner.update(sql, params); 45  } 46 
    // 查找单条记录
 @Test 49     public void find() throws SQLException { 50         QueryRunner runner = new QueryRunner(JdbcUtils.getDataSource()); 51         String sql = "select * from users where id=?"; 52         User user = (User) runner.query(sql, 1, new BeanHandler(User.class)); 53  System.out.println(user.getEmail()); 54  } 55 
    // 查找所有记录
 @Test 58     public void getAll() throws SQLException { 59         QueryRunner runner = new QueryRunner(JdbcUtils.getDataSource()); 60         String sql = "select * from users"; 61         List<User> list = (List) runner.query(sql, new BeanListHandler( 62                 User.class)); 63         for (User user : list) { 64  System.out.println(user.getEmail()); 65  } 66  } 67     
    // 批处理
 @Test 70         public void batch() throws SQLException { 71             QueryRunner runner = new QueryRunner(JdbcUtils.getDataSource()); 72             String sql = "insert into users(id,name,password,email,birthday) values(?,?,?,?,?)"; 73             
            //三条sql，五个参数
            Object params[][] = new Object[3][5]; 76             
            for(int i=0;i<params.length;i++){ 78                 params[i] = new Object[]{i+1,"aaa"+i,"123","sina.com",new Date()}; 79  } 80             
 runner.batch(sql, params); 82  } 83             
}

 

 

public class JdbcUtils {  2     private static DataSource ds;  3     static{  4         try {  5             Properties prop = new Properties();  6             InputStream in = JdbcUtils.class.getClassLoader().getResourceAsStream("dbcpconfig.properties");  7  prop.load(in);  8             
            //创建数据源
            BasicDataSourceFactory factory = new BasicDataSourceFactory(); 11             ds = factory.createDataSource(prop); 12         } catch (Exception e) { 13             throw new ExceptionInInitializerError(e); 14  } 15  } 16     
    //提供数据源
    public static DataSource getDataSource(){ 19         return ds; 20  } 21     
    //获取连接
    public static Connection  getConnection() throws SQLException{ 24         return ds.getConnection(); 25  } 26 }

 

 

 

 

2、ResultSetHandler接口的实现类

ArrayHandler：把结果集中的第一行数据转成对象数组。

ArrayListHandler：把结果集中的每一行数据都转成一个数组，再存放到List中。

BeanHandler：将结果集中的第一行数据封装到一个对应的JavaBean实例中。

BeanListHandler：将结果集中的每一行数据都封装到一个对应的JavaBean实例中，存放到List里。

ColumnListHandler：将结果集中某一列的数据存放到List中。

KeyedHandler(name)：将结果集中的每一行数据都封装到一个Map里，再把这些map再存到一个map里，其key为指定的key。

MapHandler：将结果集中的第一行数据封装到一个Map里，key是列名，value就是对应的值。

MapListHandler：将结果集中的每一行数据都封装到一个Map里，然后再存放到List

package com.dbutils;  2 import java.sql.SQLException;  3 import java.util.Arrays;  4 import java.util.List;  5 import java.util.Map;  6 
import javax.swing.JButton;  8 import org.apache.commons.dbutils.QueryRunner;  9 import org.apache.commons.dbutils.handlers.ArrayHandler;  10 import org.apache.commons.dbutils.handlers.ArrayListHandler;  11 import org.apache.commons.dbutils.handlers.ColumnListHandler;  12 import org.apache.commons.dbutils.handlers.KeyedHandler;  13 import org.apache.commons.dbutils.handlers.ScalarHandler;  14 import org.junit.Test;  15 
import com.utils.JdbcUtils;  17 
/**
 *  20  * dbutils结果集  21  *  22  */
public class Demo2 {  24  @Test  25     //把结果的第一行数据封装到数组中
    public void test1() throws SQLException{  27        QueryRunner runner = new QueryRunner(JdbcUtils.getDataSource());  28         String sql = "select * from users";  29         //强转的时候要加[]
        Object result[] = (Object[]) runner.query(sql, new ArrayHandler());  31         System.out.println(result[0]);  32         System.out.println(result[1]);  33  }  34     
 @Test  36     //把结果的每行数据封装到数组中，在把数据存放在list集合中
    public void test2() throws SQLException{  38         QueryRunner runner = new QueryRunner(JdbcUtils.getDataSource());  39         String sql = "select * from users";  40         List<Object[]> list = (List) runner.query(sql, new ArrayListHandler());  41  System.out.println(list);  42         for(Object[] objects : list){  43  System.out.println(Arrays.toString(objects));  44  }  45  }  46     
 @Test  48     //把结果集的某一列封装到一个list集合中
    public void test3() throws SQLException{  50         QueryRunner runner = new QueryRunner(JdbcUtils.getDataSource());  51         String sql = "select * from users";  52         
        List list1 = (List) runner.query(sql, new ColumnListHandler());  54         for(Object object : list1){  55  System.out.println(object);  56  }  57         
        List list2 = (List) runner.query(sql,new ColumnListHandler("name"));  59         for(Object object : list2){  60  System.out.println(object);  61  }  62         
        List list3 = (List) runner.query(sql,new ColumnListHandler(4));  64         for(Object object : list3){  65  System.out.println(object);  66  }  67  }  68     
    //KeyedHandler(name)：将结果集中的每一行数据都封装到一个Map里，再把这些map再存到一个map里，其key为指定的key
 @Test  71 public void test4() throws SQLException{ 72 QueryRunner runner = new QueryRunner(JdbcUtils.getDataSource()); 73 String sql = "select * from users"; 74 Map<Integer,Map<String,Object>> map = (Map) runner.query(sql, new KeyedHandler("id")); 75 for(Map.Entry<Integer, Map<String, Object>> me : map.entrySet()){ 76 int key = me.getKey(); 77 78 //拿到封装每条记录的map 79 for(Map.Entry<String, Object> entry:me.getValue().entrySet()){ 80 System.out.println(entry.getKey()+"="+entry.getValue()); 81 } 82 } 83 } 84  
    
 @Test  87     //获取记录总数
    public void test5() throws SQLException{  89         QueryRunner runner = new QueryRunner(JdbcUtils.getDataSource());  90         String sql = "select count(*) from users";  91         //Object result[] = (Object[]) runner.query(sql, new ArrayHandler());
        /*long totalrecord = (Long)result[0];  93  int num = (int)totalrecord;  94  System.out.println(num);  95  int totalrecord = ((Long)result[0]).intValue();  96         */
        int totalrecord = ((Long)runner.query(sql, new ScalarHandler(1))).intValue();  98  System.out.println(totalrecord);  99  } 100     
    
}