用java创建一个学生类，从键盘上输入学生信息，可以把学生信息保存在指定文本文件中的指定位置；从文本文件中读取特定学生信息；在学生类中实现学生信息的增加、删除、修改、插入等操作；要求程序是带缓存的对文本文件进行读写操作

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首先，以下是一个基本的Java学生类的代码示例，用于保存学生信息：

import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Scanner;

public class Student {
    private String name;
    private int age;
    private String gender;

    public Student(String name, int age, String gender) {
        this.name = name;
        this.age = age;
        this.gender = gender;
    }

    public String getName() {
        return name;
    }

    public int getAge() {
        return age;
    }

    public String getGender() {
        return gender;
    }

    public static void main(String[] args) throws IOException {
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入学生姓名：");
        String name = scanner.nextLine();
        System.out.println("请输入学生年龄：");
        int age = scanner.nextInt();
        scanner.nextLine();
        System.out.println("请输入学生性别：");
        String gender = scanner.nextLine();

        Student student = new Student(name, age, gender);

        BufferedWriter writer = new BufferedWriter(new FileWriter("D:\\student.txt"));
        writer.write(student.getName() + "," + student.getAge() + "," + student.getGender());
        writer.newLine();
        writer.close();
    }
}

在这个示例中，我们创建了一个学生类，其中包括学生的姓名、年龄和性别。我们使用Java的I/O API将学生信息保存到指定的文本文件中。

接下来，我们需要从文本文件中读取指定学生的信息。以下是实现该功能的代码示例：

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

public class Student {
    private String name;
    private int age;
    private String gender;

    public Student(String name, int age, String gender) {
        this.name = name;
        this.age = age;
        this.gender = gender;
    }

    public String getName() {
        return name;
    }

    public int getAge() {
        return age;
    }

    public String getGender() {
        return gender;
    }

    public static void main(String[] args) throws IOException {
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入要查询的学生姓名：");
        String name = scanner.nextLine();

        BufferedReader reader = new BufferedReader(new FileReader("D:\\student.txt"));
        List<Student> students = new ArrayList<>();

        String line;
        while ((line = reader.readLine()) != null) {
            String[] fields = line.split(",");
            Student student = new Student(fields[0], Integer.parseInt(fields[1]), fields[2]);
            students.add(student);
        }

        for (Student student : students) {
            if (student.getName().equals(name)) {
                System.out.println("学生姓名：" + student.getName());
                System.out.println("学生年龄：" + student.getAge());
                System.out.println("学生性别：" + student.getGender());
            }
        }

        reader.close();
    }
}

在这个示例中，我们使用Java的I/O API从指定的文本文件中读取所有学生的信息，并将它们保存在一个ArrayList中。然后，我们遍历ArrayList以查找指定的学生信息。

现在，我们需要在学生类中实现学生信息的增加、删除、修改和插入操作。以下是一个示例代码，用于实现这些功能：

import java.io.*;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

public class Student {
    private String name;
    private int age;
    private String gender;

    public Student(String name, int age, String gender) {
        this.name = name;
        this.age = age;
        this.gender = gender;
    }

    public String getName() {
        return name;
    }

    public int getAge() {
        return age;
    }

    public String getGender() {
        return gender;
    }

    public static void main(String[] args) throws IOException {
        Scanner scanner = new Scanner(System.in);
        System.out.println("请选择操作：");
        System.out.println("1. 添加学生信息");
        System.out.println("2. 删除学生信息");
        System.out.println("3. 修改学生信息");
        System.out.println("4. 插入学生信息");
        int choice = scanner.nextInt();
        scanner.nextLine();

        switch (choice) {
            case 1:
                addStudent();
                break;
            case 2:
                deleteStudent();
                break;
            case 3:
                modifyStudent();
                break;
            case 4:
                insertStudent();
                break;
            default:
                System.out.println("无效的选择！");
                break;
        }
    }

    private static void addStudent() throws IOException {
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入学生姓名：");
        String name = scanner.nextLine();
        System.out.println("请输入学生年龄：");
        int age = scanner.nextInt();
        scanner.nextLine();
        System.out.println("请输入学生性别：");
        String gender = scanner.nextLine();

        Student student = new Student(name, age, gender);

        BufferedWriter writer = new BufferedWriter(new FileWriter("D:\\student.txt", true));
        writer.write(student.getName() + "," + student.getAge() + "," + student.getGender());
        writer.newLine();
        writer.close();
    }

    private static void deleteStudent() throws IOException {
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入要删除的学生姓名：");
        String name = scanner.nextLine();

        List<Student> students = readStudentsFromFile();

        for (int i = 0; i < students.size(); i++) {
            if (students.get(i).getName().equals(name)) {
                students.remove(i);
            }
        }

        writeStudentsToFile(students);
    }

    private static void modifyStudent() throws IOException {
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入要修改的学生姓名：");
        String name = scanner.nextLine();

        List<Student> students = readStudentsFromFile();

        for (Student student : students) {
            if (student.getName().equals(name)) {
                System.out.println("请输入新的学生姓名：");
                String newName = scanner.nextLine();
                System.out.println("请输入新的学生年龄：");
                int newAge = scanner.nextInt();
                scanner.nextLine();
                System.out.println("请输入新的学生性别：");
                String newGender = scanner.nextLine();

                student = new Student(newName, newAge, newGender);
            }
        }

        writeStudentsToFile(students);
    }

    private static void insertStudent() throws IOException {
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入要插入的位置：");
        int position = scanner.nextInt();
        scanner.nextLine();
        System.out.println("请输入学生姓名：");
        String name = scanner.nextLine();
        System.out.println("请输入学生年龄：");
        int age = scanner.nextInt();
        scanner.nextLine();
        System.out.println("请输入学生性别：");
        String gender = scanner.nextLine();

        Student student = new Student(name, age, gender);

        List<Student> students = readStudentsFromFile();
        students.add(position, student);

        writeStudentsToFile(students);
    }

    private static List<Student> readStudentsFromFile() throws IOException {
        BufferedReader reader = new BufferedReader(new FileReader("D:\\student.txt"));
        List<Student> students = new ArrayList<>();

        String line;
        while ((line = reader.readLine()) != null) {
            String[] fields = line.split(",");
            Student student = new Student(fields[0], Integer.parseInt(fields[1]), fields[2]);
            students.add(student);
        }

        reader.close();

        return students;
    }

    private static void writeStudentsToFile(List<Student> students) throws IOException {
        BufferedWriter writer = new BufferedWriter(new FileWriter("D:\\student.txt"));
        for (Student student : students) {
            writer.write(student.getName() + "," + student.getAge() + "," + student.getGender());
            writer.newLine();
        }
        writer.close();
    }
}

在这个示例中，我们使用Java的I/O API实现了学生信息的增加、删除、修改和插入操作。我们使用一个ArrayList来保存所有学生的信息，并将它们写入指定的文本文件。

最后，你提到了要求程序是带缓存的对文本文件进行读写操作。为了实现这个要求，我们可以使用Java的BufferedReader和BufferedWriter类来带缓存地读写文本文件。在我们的示例代码中，我们已经使用了这些类来读取和写入学生信息。因此，我们的程序已经满足了这个要求。