可以查询任意表，将查询的数据封装成对象的工具类

package com.briup.jdbctest;

import java.lang.reflect.Field;
import java.math.BigDecimal;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

public class JDBCUtils {
private static Connection conn = null; // 连接对象
private static String driver = "oracle.jdbc.driver.OracleDriver"; // jar包中的OracleDriver中的类
private static String url = "jdbc:oracle:thin:@//127.0.0.1:1521/orcl";
private static String username = "scott";
private static String password = "tiger";
private static PreparedStatement ps = null;
private static ResultSet rs = null;

public static Connection getConnection() {
try {
Class.forName(driver);
conn = DriverManager.getConnection(url, username, password);

} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return conn;
}

// 将表中的数据封装成所有对象
/**
*
* @param <T> 封装对象的泛型
* @param clazz
* @param sql sql语句
* @param args 给预编译语句传参
* @return
*/
public static <T> List<T> queryToObj(Class<T> clazz, Connection conn, String sql, Object... args) {
try {
// 1. 获取结果集
ps = conn.prepareStatement(sql);
for (int i = 1; i <= args.length; i++) {
ps.setObject(i, args[i - 1]);
}
rs = ps.executeQuery();

// 2. 将查询的结果和字段名称获取 获取所有的字段
ResultSetMetaData metaData = rs.getMetaData();

// 用来保存对象的
ArrayList<T> cols = new ArrayList<>();
while (rs.next()) {
// 创建对象
T obj = clazz.newInstance();
for (int i = 1; i <= metaData.getColumnCount(); i++) {
// 通过反射获取对应的字段
Field filed = clazz.getDeclaredField(metaData.getColumnLabel(i).toLowerCase());
filed.setAccessible(true);
Object value = rs.getObject(metaData.getColumnLabel(i));
// oralce的number 在java中的是BigDecimal
if (value instanceof BigDecimal) {
value = ((BigDecimal) value).intValue();
}
filed.set(obj, value);
}
cols.add(obj);
}
return cols;
} catch (Exception e) {
e.printStackTrace();
} finally {
Close(conn, ps, rs);
}
return null;
}

// 释放资源
private static void Close(Connection conn, PreparedStatement ps, ResultSet rs) {

if (conn != null) {
try {
conn.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
if (ps != null) {
try {
ps.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
if (rs != null) {
try {
rs.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}

public static void main(String[] args) throws SQLException {

//Connection connection = getConnection();
Connection connection = JDBCUTil.getConnection();
String sql = "select * from stu where id=? or id=?";
List<Stu> list = queryToObj(Stu.class, connection, sql, 1, 2);
for (Stu stu : list) {
System.out.println(stu);
}

}
}