QueryRunner类 的應用，以及ResultSetHandler 接口的实现类

1　.该接口用于处理 java.sql.ResultSet，将数据按要求转换为另一种形式。
　　ResultSetHandler 接口提供了一个单独的方法：Object handle (java.sql.ResultSet .rs)。
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<列名,列值>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

3.示例代碼如下：

　　1.首先定義一實體類

package com.beiwo.day05.entity;

import java.io.Serializable;
import java.sql.Date;

public class Person implements Serializable{

	/**
	 *
	 */
	private static final long serialVersionUID = 1L;

	private int id;

	private String name;

	private String password;

	private String email;

	private Date birthday;

	public int getId() {
		return id;
	}

	public void setId(int 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 String getEmail() {
		return email;
	}

	public void setEmail(String email) {
		this.email = email;
	}

	public Date getBirthday() {
		return birthday;
	}

	public void setBirthday(Date birthday) {
		this.birthday = birthday;
	}

	public static long getSerialversionuid() {
		return serialVersionUID;
	}

	@Override
	public String toString() {
		return "Person [id=" + id + ", name=" + name + ", password=" + password
				+ ", email=" + email + ", birthday=" + birthday + ", getId()="
				+ getId() + ", getName()=" + getName() + ", getPassword()="
				+ getPassword() + ", getEmail()=" + getEmail()
				+ ", getBirthday()=" + getBirthday() + ", getClass()="
				+ getClass() + ", hashCode()=" + hashCode() + ", toString()="
				+ super.toString() + "]";
	}

}

測試查詢

package com.beiwo.day05.test;

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.BeanHandler;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import org.apache.commons.dbutils.handlers.ColumnListHandler;
import org.apache.commons.dbutils.handlers.MapHandler;
import org.apache.commons.dbutils.handlers.MapListHandler;
import org.apache.commons.dbutils.handlers.ScalarHandler;
import org.junit.Test;

import com.beiwo.day05.entity.Person;
import com.beiwo.day05.util.C3P0Util;

public class TestDBUtils {

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

	public void testArrayListHandler() throws SQLException{
		QueryRunner qr = new QueryRunner(C3P0Util.getDataSource());
		String sql = "SELECT * FROM person";

		List<Object[]> list = qr.query(sql, new ArrayListHandler());

		for (Object[] objects : list) {
			for (Object object : objects) {
				System.out.println(object);
			}
			System.out.println("-----------------------------");
		}
	}

	@Test //把结果集中的第一行数据转成对象数组。

	public void testArrayHandler() throws SQLException{
		QueryRunner qr = new QueryRunner(C3P0Util.getDataSource());
		String sql = "SELECT * FROM person";

		Object[] object = qr.query(sql, new ArrayHandler());
		for(Object object1 : object){
			System.out.println(object1);
		}

	}

//	@Test 将结果集中某一列的数据存放到List中。
	public void testColumnListHandler() throws SQLException{
		QueryRunner qr = new QueryRunner(C3P0Util.getDataSource());
		String sql = "SELECT name,password,email,birthday FROM person";

		List<Object> persons = qr.query(sql, new ColumnListHandler(2));
		for(Object object : persons){
			System.out.println(object);
		}

	}

	@Test //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。

	public void testMapHandler() throws SQLException{
		QueryRunner qr = new QueryRunner(C3P0Util.getDataSource());
		String sql = "SELECT * FROM person WHERE id=?";

		Map<String, Object> map= qr.query(sql, new MapHandler(),1);
		for (Map.Entry<String, Object> m:map.entrySet()) {
			System.out.println(m.getKey() + "\t" + m.getValue());
		}

	}

	@Test //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

	public void testMapListHandler() throws SQLException{
		QueryRunner qr = new QueryRunner(C3P0Util.getDataSource());
		String sql = "SELECT * FROM person ";

		List<Map<String, Object>> list = qr.query(sql, new MapListHandler());
		for (Map<String, Object> map : list) {
			for (Map.Entry<String, Object> m : map.entrySet()) {
				System.out.println(m.getKey() + "\t" + m.getValue());
			}
			System.out.println("--------------------------------------------");
		}

	}

	@Test //查询数据库中信息的总条数
	public void testScalarHandler() throws SQLException{
		QueryRunner qr = new QueryRunner(C3P0Util.getDataSource());
		String sql = "SELECT COUNT(*) FROM person ";

	Long l = (Long)qr.query(sql, new ScalarHandler(1));
	System.out.println(l);

	}

	@Test //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。

	public void testBeanListHandler() throws SQLException{
		QueryRunner qr = new QueryRunner(C3P0Util.getDataSource());
		String sql = "SELECT * FROM person ";

	List<Person> list = qr.query(sql, new BeanListHandler<Person>(Person.class));
	System.out.println(list);
	}

	@Test //将结果集中的第一行数据封装到一个对应的JavaBean实例中。
	public void testBeanHandler() throws SQLException{
		QueryRunner qr = new QueryRunner(C3P0Util.getDataSource());
		String sql = "SELECT * FROM person WHERE id=?";

	Person person = qr.query(sql, new BeanHandler<Person>(Person.class),1);
	System.out.println(person);
	}
}

測試增刪改

package com.beiwo.day05.test;

import java.sql.SQLException;
import java.util.Date;

import org.apache.commons.dbutils.QueryRunner;
import org.junit.Test;

import com.beiwo.day05.util.C3P0Util;

public class TestUpDate {

	@Test
	public void testInsert() throws SQLException{
		QueryRunner qRunner = new QueryRunner(C3P0Util.getDataSource());
		String sql = "INSERT INTO person(name,password,email,birthday)VALUES(?,?,?,?)";
		qRunner.update(sql, "ccc","789","789@qq.com",new Date());
	}

	@Test
	public void testUpDate1() throws SQLException{
		QueryRunner qRunner = new QueryRunner(C3P0Util.getDataSource());
		String sql = "UPDATE person SET name='www' WHERE id=2";
		qRunner.update(sql);
	}

	@Test
	public void testUpDate2() throws SQLException{
		QueryRunner qRunner = new QueryRunner(C3P0Util.getDataSource());
		String sql = "DELETE FROM person WHERE id=6";
		qRunner.update(sql);
	}

}