工作室java学习，提交代码

package manage; import javax.swing.*; import java.awt.*; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.io.*; import java.util.ArrayList; import java.util.HashMap; import java.util.Map; //因为要写入对象文件，所以必须序列化 class Students implements Serializable{ private int id; private String name; private int age; public Students(int id,String name,int age){ this.id=id; this.name=name; this.age=age; } public int getId(){ return id; } public String getName(){ return name; } public int getAge(){ return age; } public String toString(){ return id+" "+name+" "+age; } public void setId(int id){ this.id=id; } public void setName(String name){ this.name=name; } public void setAge(int age){ this.age=age; } } class ManageSystem{ private final static String filename="students.dat"; private ArrayList<Students>arrayList=new ArrayList<>(); //主界面 JFrame jFrame=new JFrame("Student Manage System"); //按钮 JButton addButton=new JButton("添加学生"); JButton modifyButton=new JButton("修改学生"); JButton deleteButton=new JButton("删除学生"); JButton searchButton=new JButton("查找学生"); JButton showButton=new JButton("显示学生"); JButton exitButton=new JButton("退出系统"); public ManageSystem(){ //设置界面的大小，位置，以及组件 jFrame.setSize(800,700); jFrame.setLocation(600,200); jFrame.setLayout(null); addButton.setBounds(200,50,400,75); modifyButton.setBounds(200,150,400,75); deleteButton.setBounds(200,250,400,75); searchButton.setBounds(200,350,400,75); showButton.setBounds(200,450,400,75); exitButton.setBounds(200,550,400,75); jFrame.add(addButton); jFrame.add(modifyButton); jFrame.add(deleteButton); jFrame.add(searchButton); jFrame.add(showButton); jFrame.add(exitButton); addButton.setVisible(true); modifyButton.setVisible(true); deleteButton.setVisible(true); searchButton.setVisible(true); showButton.setVisible(true); exitButton.setVisible(true); //读取文件 try{ FileInputStream fileInputStream=new FileInputStream(filename); ObjectInputStream objectInputStream=new ObjectInputStream(fileInputStream); Students students=null; while((students=(Students)objectInputStream.readObject())!=null) arrayList.add(students); objectInputStream.close(); fileInputStream.close(); } catch(Exception e){ e.printStackTrace(); } } //添加学生 public void AddStudent(){ addButton.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { //设置新界面 JDialog addDialog=new JDialog(jFrame); addDialog.setLayout(new FlowLayout()); //界面标题 addDialog.setTitle("添加学生"); addDialog.setSize(800,700); addDialog.setLocation(600,200); //设置相关标签和文本框 JLabel idLabel=new JLabel("学号:"); JTextField idField=new JTextField(""); idField.setPreferredSize(new Dimension(100,50)); JLabel nameLabel=new JLabel("姓名："); JTextField nameField=new JTextField(""); nameField.setPreferredSize(new Dimension(100,50)); JLabel ageLabel=new JLabel("年龄："); JTextField ageField=new JTextField(""); ageField.setPreferredSize(new Dimension(100,50)); idLabel.setVisible(true); idField.setVisible(true); nameLabel.setVisible(true); nameField.setVisible(true); ageLabel.setVisible(true); ageField.setVisible(true); //将组件添加进入副界面addDialog addDialog.add(idLabel); addDialog.add(idField); addDialog.add(nameLabel); addDialog.add(nameField); addDialog.add(ageLabel); addDialog.add(ageField); addDialog.setVisible(true); //设置提交按钮 JButton submitButton=new JButton("确定"); submitButton.setBounds(300,400,200,75); submitButton.setVisible(true); addDialog.add(submitButton); submitButton.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { //获取输入的内容 int id=Integer.parseInt(idField.getText()); String name=nameField.getText(); int age=Integer.parseInt(ageField.getText()); Students students=new Students(id,name,age); arrayList.add(students); //提交后返回主页面 addDialog.setVisible(false); } }); //设置返回按钮 JButton returnbutton=new JButton("返回"); returnbutton.setBounds(300,500,200,75); returnbutton.setLayout(null); returnbutton.setVisible(true); addDialog.add(returnbutton); returnbutton.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { //返回主页面 addDialog.setVisible(false); } }); jFrame.add(addDialog); } }); } //修改学生信息 public void ModifyStudent(){ modifyButton.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { //设置新界面 JDialog modifyDialog=new JDialog(jFrame); modifyDialog.setTitle("修改学生"); modifyDialog.setSize(800,700); modifyDialog.setLocation(600,200); modifyDialog.setLayout(null); modifyDialog.setVisible(true); //搜索条件 JLabel namelabel=new JLabel("姓名"); JTextField namefield=new JTextField(""); namelabel.setBounds(100,0,60,40); namefield.setBounds(160,0,200,40); namelabel.setLayout(null); namefield.setLayout(null); namelabel.setVisible(true); namefield.setVisible(true); modifyDialog.add(namelabel); modifyDialog.add(namefield); //设置查询按钮 JButton searchbutton=new JButton("查询"); searchbutton.setBounds(0,0,60,40); searchbutton.setLayout(null); searchbutton.setVisible(true); modifyDialog.add(searchbutton); searchbutton.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { //将符合条件的学生加入哈希表 Map<Integer,Students>map=new HashMap<>(); for(int i=0;i<arrayList.size();++i) { if(namefield.getText().equals(arrayList.get(i).getName()