1. 在IDEA中，使用JDBC对stu表进行如下操作： 添加一条记录： id = 4，name = 赵六，age = 37。 修改记录：将王五的年纪修改为88岁。 删除一条记录：删除李四所在行的记录。定义Stu类 定义方法 public List<Stu> findAll(){} 实现方法 select * from stu;

好的，您的问题是如何使用JDBC对stu表进行增删改查操作，并且定义Stu类和实现findAll方法。下面是代码实现：

import java.sql.*;
import java.util.ArrayList;
import java.util.List;

public class JDBCExample {
    private static final String URL = "jdbc:mysql://localhost:3306/test";
    private static final String USER = "root";
    private static final String PASSWORD = "password";

    public static void main(String[] args) {
        // 添加一条记录
        addRecord(4, "赵六", 37);
        // 修改记录
        updateRecord("王五", 88);
        // 删除一条记录
        deleteRecord("李四");

        // 查询所有记录
        List<Stu> stus = findAll();
        for (Stu stu : stus) {
            System.out.println(stu);
        }
    }

    public static void addRecord(int id, String name, int age) {
        String sql = "INSERT INTO stu (id, name, age) VALUES (?, ?, ?)";
        try (Connection conn = DriverManager.getConnection(URL, USER, PASSWORD);
             PreparedStatement ps = conn.prepareStatement(sql)) {
            ps.setInt(1, id);
            ps.setString(2, name);
            ps.setInt(3, age);
            ps.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public static void updateRecord(String name, int age) {
        String sql = "UPDATE stu SET age=? WHERE name=?";
        try (Connection conn = DriverManager.getConnection(URL, USER, PASSWORD);
             PreparedStatement ps = conn.prepareStatement(sql)) {
            ps.setInt(1, age);
            ps.setString(2, name);
            ps.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public static void deleteRecord(String name) {
        String sql = "DELETE FROM stu WHERE name=?";
        try (Connection conn = DriverManager.getConnection(URL, USER, PASSWORD);
             PreparedStatement ps = conn.prepareStatement(sql)) {
            ps.setString(1, name);
            ps.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public static List<Stu> findAll() {
        List<Stu> stus = new ArrayList<>();
        String sql = "SELECT * FROM stu";
        try (Connection conn = DriverManager.getConnection(URL, USER, PASSWORD);
             Statement stmt = conn.createStatement();
             ResultSet rs = stmt.executeQuery(sql)) {
            while (rs.next()) {
                int id = rs.getInt("id");
                String name = rs.getString("name");
                int age = rs.getInt("age");
                stus.add(new Stu(id, name, age));
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return stus;
    }
}

class Stu {
    private int id;
    private String name;
    private int age;

    public Stu(int id, String name, int age) {
        this.id = id;
        this.name = name;
        this.age = age;
    }

    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 int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    @Override
    public String toString() {
        return "Stu{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", age=" + age +
                '}';
    }
}

在这个例子中，我们首先定义了一个JDBCExample类，其中包含了添加、修改、删除和查询方法。然后我们定义了一个Stu类来表示学生记录，并实现了一个findAll方法来查询所有学生记录。在每个JDBC操作中，我们都使用try-with-resources语句来自动关闭连接、语句和结果集。