DbUtils常用API的使用 方便以后查阅

  1 package com.lizhou.Test;
  2 
  3 import java.sql.SQLException;
  4 import java.util.List;
  5 import java.util.Map;
  6 import java.util.Map.Entry;
  7 import java.util.Set;
  8 
  9 import javax.sql.DataSource;
 10 
 11 import org.apache.commons.dbutils.QueryRunner;
 12 import org.apache.commons.dbutils.handlers.ArrayHandler;
 13 import org.apache.commons.dbutils.handlers.ArrayListHandler;
 14 import org.apache.commons.dbutils.handlers.BeanHandler;
 15 import org.apache.commons.dbutils.handlers.BeanListHandler;
 16 import org.apache.commons.dbutils.handlers.MapHandler;
 17 import org.apache.commons.dbutils.handlers.MapListHandler;
 18 import org.apache.commons.dbutils.handlers.ScalarHandler;
 19 
 20 import com.lizhou.Domain.Account;
 21 import com.lizhou.Util.MysqlUtil;
 22 
 23 
 24 /**
 25  * DbUtils框架的使用
 26  * 目的:减轻CURD操作
 27  * DbUtils框架最核心的类,就是QueryRunner类,构造其有空参构造和带连接池(DataSource)的构造
 28  * 
 29  * 
 30  * 
 31  * @author bojiangzhou
 32  *
 33  */
 34 public class DbUtils {
 35     
 36     public static void main(String[] args) {
 37         /**
 38          * 数据库为test,在c3p0-config.xml中配置
 39          */
 40         
 41 //        queryRunner();
 42         
 43         //下面是ResultSetHandler的接口的各种实现类的用法(7个实现类)
 44         
 45 //        beanHandler();        //针对JavaBean
 46         
 47 //        beanListHandler();    //针对JavaBean
 48         
 49 //        arrayHandler();        //针对数组
 50         
 51 //        arrayListHandler();    //针对数组
 52         
 53 //        mapHandler();        //针对Map
 54         
 55 //        mapListHandler();    //针对Map
 56         
 57         scalarHandler();    //针对Long
 58         
 59     }
 60     
 61     //QueryRunner
 62     public static void queryRunner(){
 63         //获取连接池
 64         DataSource ds = MysqlUtil.getPool();
 65         //用连接池构造一个QueryRunner
 66         QueryRunner qr = new QueryRunner(ds);
 67         
 68 //        String sql = "update account set name=? where id=?";
 69         String sql = "insert into account(name, money) values(?, ?)";
 70         
 71         try {
 72 //            qr.update(sql, new Object[]{"O(∩_∩)O哈哈~", 2});
 73             qr.update(sql, new Object[]{"一生有你", 25000});
 74         } catch (SQLException e) {
 75             // TODO Auto-generated catch block
 76             e.printStackTrace();
 77         }
 78     }
 79     
 80     //BeanHandler
 81     public static void beanHandler(){
 82         QueryRunner qr = new QueryRunner(MysqlUtil.getPool());
 83         
 84         String sql = "select * from account where id = ?";
 85         
 86         try {
 87             Account acc = (Account) qr.query(sql, new Object[]{3}, new BeanHandler(Account.class));
 88             System.out.println(acc.getId()+"    "+acc.getName()+"    "+acc.getMoney());
 89         } catch (SQLException e) {
 90             e.printStackTrace();
 91         }
 92         
 93     }
 94     
 95     //BeanListHandler
 96     public static void beanListHandler(){
 97         QueryRunner qr = new QueryRunner(MysqlUtil.getPool());
 98         
 99         String sql = "select * from account";
100         
101         try {
102             List<Account> accounts =  (List<Account>) qr.query(sql, new BeanListHandler(Account.class));
103             for(Account a : accounts){
104                 System.out.println(a.getId()+"    "+a.getName()+"    "+a.getMoney());
105             }
106         } catch (SQLException e) {
107             e.printStackTrace();
108         }
109     }        
110     
111     //ArrayHandler
112     public static void arrayHandler(){
113         QueryRunner qr = new QueryRunner(MysqlUtil.getPool());
114         
115         String sql = "select * from account where money=?";
116         
117         try {
118             Object[] a = (Object[]) qr.query(sql, 10000, new ArrayHandler()); 
119             for(int i = 0;i < a.length;i++){
120                 System.out.print(a[i]+"    ");
121             }
122             System.out.println("
------------------------------");
123         } catch (SQLException e) {
124             e.printStackTrace();
125         }
126     }    
127     
128     //ArrayListHandler
129     public static void arrayListHandler(){
130         QueryRunner qr = new QueryRunner(MysqlUtil.getPool());
131         
132         String sql = "select * from account";
133         
134         try {
135              List<Object[]> accounts = (List<Object[]>) qr.query(sql, new ArrayListHandler()); 
136             for(Object[] obj : accounts){
137                 for(int i = 0;i < obj.length;i++){
138                     System.out.print(obj[i]+"    ");
139                 }
140                 System.out.println("
------------------------------");
141             }
142         } catch (SQLException e) {
143             e.printStackTrace();
144         }
145     }    
146     
147     //MapHandler
148     public static void mapHandler(){
149         QueryRunner qr = new QueryRunner(MysqlUtil.getPool());
150         
151         String sql = "select * from account";
152         
153         try {
154              Map<Object, Object> map = (Map<Object, Object>) qr.query(sql, new MapHandler());
155              Set<Entry<Object, Object>> entry = map.entrySet();
156              for(Entry e : entry){
157                  System.out.print(e.getKey()+"    ");
158                  System.out.println(e.getValue());
159              }
160         } catch (SQLException e) {
161             e.printStackTrace();
162         }
163     }    
164     
165     //MapListHandler
166     public static void mapListHandler(){
167         QueryRunner qr = new QueryRunner(MysqlUtil.getPool());
168         
169         String sql = "select * from account";
170         
171         try {
172              List< Map<Object, Object> > maps = (List<Map<Object, Object>>) qr.query(sql, new MapListHandler());
173              for(Map<Object, Object> map : maps){
174                  Set<Entry<Object, Object>> entry = map.entrySet();
175                  for(Entry e : entry){
176                      System.out.print(e.getKey()+"    ");
177                      System.out.println(e.getValue());
178                  }
179                  System.out.println("-------------------------");
180              }
181              
182         } catch (SQLException e) {
183             e.printStackTrace();
184         }
185     }    
186     
187     
188     //ScalarHandler 只返回一行一列数据
189     public static void scalarHandler(){
190         QueryRunner qr = new QueryRunner(MysqlUtil.getPool());
191         
192         String sql = "select count(*) from account";
193         
194         try {
195              Object obj = qr.query(sql, new ScalarHandler());
196              System.out.println(obj);
197         } catch (SQLException e) {
198             e.printStackTrace();
199         }
200     }    
201     
202 }
原文地址:https://www.cnblogs.com/chiangchou/p/dbutils-api.html