dbutils是对JDBC的一个简单的包装，可以说是JDBC的一个比较实用的工具，现在有些公司还都在使用dbutils开发，所以wo'm我们有必要了解一下dbutils。首先说一个dbutils的一个环境，使用dbutils需要commons-dbutils-1.2.jar jar包依赖，如果c3p0做连接池还需要c3p0-0.9.2-pre1.jar 和 mchange-commons-0.2.jar jar包，如果shi'使用dbcp做连接池，还需要commons-dbcp-1.2.2.jar 和 commons-pool.jar 和 commons-logging-1.1.1.jar jar包依赖。搭建好huan环境，下面我们来了解一下处理器的名称和作用，增删除改操作都是基于某些处理器上实现的。
结果集处理器: 作用
(1)ArrayHandler 把结果集第一行数据转化成对象数组
(2)ArrayListHandler 把结果集中的每一行数据都转成一个数组,在存放到List中
(3)BeanHandler 将结果集的第一行封装到第一个对应的JavaBean实例中
(4)BeanListHander 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。
(5)ColumnListHandler("列名) 将结果集中某一列的数据存放到List中
(6)KeyedHandler(key) 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
(7)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。
(8)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
(9)ScalarHandler 将处理的结果转到一个对象中去
具体案例如下：
@Test
public void Insert() throws SQLException{
QueryRunner runner = new QueryRunner(JDBCUtil_c3p0.getDataSource());
System.out.println("runner:"+runner);
String sql = "insert into user(id,name,password,email,birthday) values(?,?,?,?,?)";
Object params[] = {1,"aaa","123","[email protected]",new Date()};
runner.update(sql, params);
}
@Test
public void update() throws SQLException{
QueryRunner runner = new QueryRunner(JDBCUtil_c3p0.getDataSource());
System.out.println("runner:"+runner);
String sql = "update user set email = ? where id = ?";
Object params[] = {"[email protected]",1};
runner.update(sql, params);
}
@Test
public void delete() throws SQLException{
QueryRunner runner = new QueryRunner(JDBCUtil_c3p0.getDataSource());
System.out.println("runner:"+runner);
String sql = "delete from user where id = ?";
runner.update(sql, 1);
}
/**
BeanHandler(对像)
User:com.nyist.dbutils.model.user@5b464ce8
* @throws SQLException
*/
@Test
public void find() throws SQLException{
QueryRunner runner = new QueryRunner(JDBCUtil_c3p0.getDataSource());
System.out.println("runner:"+runner);
String sql = "select * from user where id = ?";
user user = (user) runner.query(sql, 1, new BeanHandler(user.class));
System.out.println("User:"+user);
}
/**
BeanListHandler(对象)
user:[com.nyist.dbutils.model.user@340f438e, com.nyist.dbutils.model.user@30c7da1e, com.nyist.dbutils.model.user@5b464ce8]
* @throws SQLException
*/
@Test
public void getAll() throws SQLException{
QueryRunner runner = new QueryRunner(JDBCUtil_c3p0.getDataSource());
System.out.println("runner:"+runner);
String sql = "select * from user";
List<user> user = (List<user>) runner.query(sql,new BeanListHandler(user.class));
System.out.println("user:"+user);
}
//batch批处理sql
@Test
public void batch() throws SQLException{
QueryRunner runner = new QueryRunner(JDBCUtil_c3p0.getDataSource());
String sql = "insert into user(id,name,password,email,birthday) values(?,?,?,?,?)";
Object params[][] = new Object[3][5]; //二位数组用来保存sql 的长度和sql 的个数
int i =0;
for(i=0;i<params.length;i++){
params[i] = new Object[]{i+1,"ccc","123",i+"[email protected]",new Date()}; //利用for循环填充二位数组
}
runner.batch(sql, params);
}
/**
ScalarHandler
TotalRecord:3
* @throws SQLException
*/
@Test
public void getCount() throws SQLException{
QueryRunner runner = new QueryRunner(JDBCUtil_c3p0.getDataSource());
String sql = "select count(*) from user";
//Object result[] = (Object[]) runner.query(sql,new ArrayHandler());
/* 第一种做法
long num = (long)result[0];
int number = (int)num;
System.out.println("number:"+number);*/
/*第二种做法
int totalrecord = ((Long)result[0]).intValue();
System.out.print("TotalRecord:"+totalrecord);*/
/*
第三种做法 使用ScalarHandler 作用:将处理的结果转到一个对象中去
* */
int totalrecord = ((Long)runner.query(sql,new ScalarHandler())).intValue();
System.out.println("TotalRecord:"+totalrecord);
}
处理器应用案例：
package com.nyist.dbutils.Demo;
import java.sql.SQLException;
import java.util.List;
import java.util.Map;import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.ArrayHandler;
import org.apache.commons.dbutils.handlers.ArrayListHandler;
import org.apache.commons.dbutils.handlers.ColumnListHandler;
import org.apache.commons.dbutils.handlers.KeyedHandler;
import org.apache.commons.dbutils.handlers.MapHandler;
import org.apache.commons.dbutils.handlers.MapListHandler;
import org.junit.Test;import com.nyist.dbutils.Utils.JDBCUtil_c3p0;
public class Demo2 {
/**
ArrayHandler()
Object:1
Object:[email protected]
* @throws SQLException
*/
@Test
public void test1() throws SQLException{
QueryRunner runner = new QueryRunner(JDBCUtil_c3p0.getDataSource());
System.out.println("runner:"+runner);
String sql = "select * from user where id = ?";
Object object[]= (Object[]) runner.query(sql, 1, new ArrayHandler());
System.out.println("Object:"+object[0]);
System.out.println("Object:"+object[3]);
}
/**
ArrayListHandler()
List:[[Ljava.lang.Object;@57829d67, [Ljava.lang.Object;@19dfb72a, [Ljava.lang.Object;@17c68925]
* @throws SQLException
*/
@Test
public void test2() throws SQLException{
QueryRunner runner = new QueryRunner(JDBCUtil_c3p0.getDataSource());
System.out.println("runner:"+runner);
String sql = "select * from user";
List list = (List)runner.query(sql,new ArrayListHandler());
System.out.println("List:"+list);
}
/**
ColumnListHandler()
List:[[email protected], [email protected], [email protected]]
* @throws SQLException
*/
@Test
public void test3() throws SQLException{
QueryRunner runner = new QueryRunner(JDBCUtil_c3p0.getDataSource());
System.out.println("runner:"+runner);
String sql = "select * from user";
List list = (List)runner.query(sql,new ColumnListHandler("email"));
System.out.println("List:"+list);
}
/**
KeyedHandler("key")
ID:1
birthday=2018-07-18
password=123
name=ccc
id=1
[email protected]
ID:2
birthday=2018-07-18
password=123
name=ccc
id=2
[email protected]
ID:3
birthday=2018-07-18
password=123
name=ccc
id=3
[email protected]
* @throws SQLException
*/
@Test
public void test4() throws SQLException{
QueryRunner runner = new QueryRunner(JDBCUtil_c3p0.getDataSource());
System.out.println("runner:"+runner);
String sql = "select * from user";
Map<Integer,Map<String,Object>> map = (Map<Integer,Map<String,Object>>) runner.query(sql,new KeyedHandler("id"));
for(Map.Entry<Integer,Map<String,Object>> me : map.entrySet()) {
int id = me.getKey();
System.out.println("ID:"+id);
for(Map.Entry<String,Object> entry:me.getValue().entrySet()){
String key = entry.getKey();
Object object = entry.getValue();
System.out.println(key + "=" +object);
}
}
}
/**
MapHandler()
birthday=2018-07-18
password=123
name=ccc
id=3
[email protected]
* @throws SQLException
*/
@Test
public void test5() throws SQLException{
QueryRunner runner = new QueryRunner(JDBCUtil_c3p0.getDataSource());
System.out.println("runner:"+runner);
String sql = "select * from user where id = ?";
Map<String,Object> map = (Map) runner.query(sql,3,new MapHandler());
for(Map.Entry<String,Object> me:map.entrySet()){
String key = me.getKey();
Object object = me.getValue();
System.out.println(key+"="+object);
}
}
/**
MapListHandler()
birthday=2018-07-18
password=123
name=ccc
id=1
[email protected]
birthday=2018-07-18
password=123
name=ccc
id=2
[email protected]
birthday=2018-07-18
password=123
name=ccc
id=3
[email protected]
* @throws SQLException
*/
@Test
public void test6() throws SQLException{
QueryRunner runner = new QueryRunner(JDBCUtil_c3p0.getDataSource());
System.out.println("runner:"+runner);
String sql = "select * from user";
List<Map<String,Object>> list = (List) runner.query(sql,new MapListHandler());
for(int i=0;i<list.size();i++){
Map<String,Object> map = list.get(i);
for (Map.Entry<String,Object> entry:map.entrySet()) {
String key = entry.getKey();
Object object = entry.getValue();
System.out.println(key+"="+object);
}
}
}
}