JDBC学习（十二）：使用BeanHandler实现查询

1、查询一条数据（针对Beauty表）

package demo07;

import java.sql.Connection;
import java.util.List;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import org.junit.jupiter.api.Test;

import utils.Beauty;
import utils.JDBCUtils;

public class DbutilsQueryTest {

	
	/**
	 * BeanHandler是ResultSetHandler的实现类，用于封装表中的一条记录
	 * @throws Exception
	 */
	@Test
	public void test1(){
		
		Connection conn = null;
		try {
			QueryRunner runner = new QueryRunner();
			conn = JDBCUtils.getConnectionDruid();
			String sql = "select id,name,borndate from beauty where id=?";
			BeanHandler<Beauty> handler = new BeanHandler<>(Beauty.class);
			Beauty beauty = runner.query(conn, sql, handler, 10);
			System.out.println(beauty);
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			JDBCUtils.closeResourse(conn, null);
			
		}
		
	}
	
}

2、查询多条数据（构成集合）

package demo07;

import java.sql.Connection;
import java.util.List;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import org.junit.jupiter.api.Test;

import utils.Beauty;
import utils.JDBCUtils;

public class DbutilsQueryTest {
	
	/*
	 * 测试查询:查询多条记录构成的集合
	 * 
	 * 使用ResultSetHandler的实现类：BeanListHandler
	 */
	@Test
	public void test2() {
		
		Connection conn = null;
		try {
			QueryRunner runner = new QueryRunner();
			conn = JDBCUtils.getConnectionDruid();
			String sql = "select id,name,borndate from beauty where id<?";
			BeanListHandler<Beauty> handler = new BeanListHandler<>(Beauty.class);
			List<Beauty> list = runner.query(conn, sql, handler, 10);
			list.forEach(System.out::println);
		} catch (Exception e) {
			e.printStackTrace();
		}
		
		JDBCUtils.closeResourse(conn, null);
	}
	
	
}