Java 如何获取当前/上次数据（不初始化）NetBeans？

注意：我有这个问题，由Unity3D中的C#解决（没有数据库）

问题概述 在NetBeans（Java）中，我有这样一种形式：

我想要报表中的“报告”，就像从输入数据中的“报告”

我创建了2个表单类和1个java类

“主代码”JavaClass

    private String name;
    private int age;
    private String address;

    mainCode mainCode = new mainCode();
    LookData lookData = new LookData();

    String name;
    int age;
    String address;
    /**
     * Creates new form InputData
     */
    public InputData() {
        initComponents();
    }

    public void setData(){
        mainCode.setName(jTextField1.getText());
        mainCode.setAge(Integer.parseInt(jTextField2.getText()));
        mainCode.setAddress(jTextArea1.getText());
    }

    public void getData(){
        name = mainCode.getName();
        age = mainCode.getAge();
        address = mainCode.getAddress();
    }

    public void printData(){
        String data = null;
        data =  "BIODATA REPORT \n"
                + "Your Name    : "+name+"\n"
                + "Your Age     : "+age+"\n"
                + "Your Address : "+address+"\n";
        jTextArea2.setText(data);
    }

    public void ClearData(){
        String kosong = "";
        jTextArea1.setText(kosong);
        jTextArea2.setText(kosong);
        jTextField1.setText(kosong);
        jTextField2.setText(kosong);
    }

    mainCode mainCode = new mainCode();

    String name;
    int age;
    String address;

    public LookData() {
        initComponents();
    }

    public void getData(){
        name = mainCode.getName();
        age = mainCode.getAge();
        address = mainCode.getAddress();
    }

    public void printData(){
        String data = null;
        data =  "BIODATA REPORT\n"
                + "Your Name    : "+name+"\n"
                + "Your Age     : "+age+"\n"
                + "Your Address : "+address+"\n";
        jTextArea2.setText(data);
    }

当然还有塞特和盖特

“InputData”JavaFORMClass

    private String name;
    private int age;
    private String address;

    mainCode mainCode = new mainCode();
    LookData lookData = new LookData();

    String name;
    int age;
    String address;
    /**
     * Creates new form InputData
     */
    public InputData() {
        initComponents();
    }

    public void setData(){
        mainCode.setName(jTextField1.getText());
        mainCode.setAge(Integer.parseInt(jTextField2.getText()));
        mainCode.setAddress(jTextArea1.getText());
    }

    public void getData(){
        name = mainCode.getName();
        age = mainCode.getAge();
        address = mainCode.getAddress();
    }

    public void printData(){
        String data = null;
        data =  "BIODATA REPORT \n"
                + "Your Name    : "+name+"\n"
                + "Your Age     : "+age+"\n"
                + "Your Address : "+address+"\n";
        jTextArea2.setText(data);
    }

    public void ClearData(){
        String kosong = "";
        jTextArea1.setText(kosong);
        jTextArea2.setText(kosong);
        jTextField1.setText(kosong);
        jTextField2.setText(kosong);
    }

    mainCode mainCode = new mainCode();

    String name;
    int age;
    String address;

    public LookData() {
        initComponents();
    }

    public void getData(){
        name = mainCode.getName();
        age = mainCode.getAge();
        address = mainCode.getAddress();
    }

    public void printData(){
        String data = null;
        data =  "BIODATA REPORT\n"
                + "Your Name    : "+name+"\n"
                + "Your Age     : "+age+"\n"
                + "Your Address : "+address+"\n";
        jTextArea2.setText(data);
    }

“LookData”JavaFORMClass

    private String name;
    private int age;
    private String address;

    mainCode mainCode = new mainCode();
    LookData lookData = new LookData();

    String name;
    int age;
    String address;
    /**
     * Creates new form InputData
     */
    public InputData() {
        initComponents();
    }

    public void setData(){
        mainCode.setName(jTextField1.getText());
        mainCode.setAge(Integer.parseInt(jTextField2.getText()));
        mainCode.setAddress(jTextArea1.getText());
    }

    public void getData(){
        name = mainCode.getName();
        age = mainCode.getAge();
        address = mainCode.getAddress();
    }

    public void printData(){
        String data = null;
        data =  "BIODATA REPORT \n"
                + "Your Name    : "+name+"\n"
                + "Your Age     : "+age+"\n"
                + "Your Address : "+address+"\n";
        jTextArea2.setText(data);
    }

    public void ClearData(){
        String kosong = "";
        jTextArea1.setText(kosong);
        jTextArea2.setText(kosong);
        jTextField1.setText(kosong);
        jTextField2.setText(kosong);
    }

    mainCode mainCode = new mainCode();

    String name;
    int age;
    String address;

    public LookData() {
        initComponents();
    }

    public void getData(){
        name = mainCode.getName();
        age = mainCode.getAge();
        address = mainCode.getAddress();
    }

    public void printData(){
        String data = null;
        data =  "BIODATA REPORT\n"
                + "Your Name    : "+name+"\n"
                + "Your Age     : "+age+"\n"
                + "Your Address : "+address+"\n";
        jTextArea2.setText(data);
    }

结论 可能这个问题是因为我必须像这样创建和初始化类

mainCode mainCode = new mainCode();

正因为如此，每当我运行这个程序时，这个类都会被重置为默认值，在lookData格式中，数据会显示null或零

我已经意识到这一点，并尝试了

mainCode mainCode;
mainCode mainCode = code.mainCode();
String name = code.mainCode.name;

他们都给出了错误的答案

谁知道如何解决这个问题

谢谢

---

我尽可能详细地尝试过，如果这有问题，我很抱歉。

我想您正在尝试从现有的输入数据表单中查找保存的记录，如果当您按下“从另一个表单查看”按钮时，查找弹出，则将主代码obj传递给LookData的构造函数。下面是做这件事的方法

LookData代码：

    MainCode mainCode;

    String name;
    int age;
    String address;

    public LookData(MainCode main) {
        this.mainCode = main;
        initComponents();
    }

    public void getData(){
        name = mainCode.getName();
        age = mainCode.getAge();
        address = mainCode.getAddress();
    }

    public void printData(){
        String data = null;
        data =  "BIODATA REPORT\n"
                + "Your Name    : "+name+"\n"
                + "Your Age     : "+age+"\n"
                + "Your Address : "+address+"\n";
        jTextArea2.setText(data);
    }

---

我认为你基本上走对了方向。您需要做的是确保两个表单引用同一个对象。你需要一个

newmaincode（）

，但应该只有一个。我知道逻辑，但我不知道怎么做。web上的每个示例都是针对eclipse的。我已经尝试将lookData代码更改为上面的样子。但是有错误消息说“java.lang.NullPointerException”。可能是因为当我点击“从另一个表单查看”按钮时，我没有将主代码对象传递到查看数据中。您能告诉我如何将MainCode对象从InputData JavaFormClass传递到LookData JavaFormClass吗？thx.sory和thx我的问题解决了，我只需要在这些按钮上添加一行“newlookdata（mainCode）.setVisible（true）；”。