Question

我想从文本字段中读取数据，将其保存在第一个类的数组中在第二节课我想在文本字段中显示这些数据，但我的程序没有返回任何内容

这里是第一堂课

import java.util.ArrayList;
public class Patient extends javax.swing.JFrame {
int emg;
String clas;
String day;
int sex;
String name;
String cls;
int count;
boolean[] Assignbed = new boolean[31];
ArrayList<Integer> list1;
ArrayList list2=new ArrayList();
ArrayList list3;
    /**
     *
     */
    public Patient() {
        this.list3 = new ArrayList<Integer>();
        this.list1 = new ArrayList<Integer>();
        initComponents();
    }
    private void jMenuItem1ActionPerformed(java.awt.event.ActionEvent evt) {                                           
    AWellcome a=new AWellcome();
    a.setVisible(true);
    dispose();
    }                                          

    private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {                                         
    Name();
    }                                                                               

    private void jButton6ActionPerformed(java.awt.event.ActionEvent evt) {                                         
    Level();
    }                                                                                                                                                                   

    private void jButton4ActionPerformed(java.awt.event.ActionEvent evt) {                                         
    occupation();
    }                                        

    private void jButton5ActionPerformed(java.awt.event.ActionEvent evt) {                                         
    Sex();
    }                                                                                                                      

    private void jButton3ActionPerformed(java.awt.event.ActionEvent evt) {                                         
    Age();
    }                                        

    private void jButton7ActionPerformed(java.awt.event.ActionEvent evt) {                                         
    Payment();
    }                                        

    private void jButton8ActionPerformed(java.awt.event.ActionEvent evt) {                                         
    Reserve();
    }                                        

    private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                         
    Date();
    }                                                                                                                                                                

    private void jButton9ActionPerformed(java.awt.event.ActionEvent evt) {                                         
    Department();
    }                                        
public ArrayList<Integer> getList() {
       return list1;
   }
public void Department(){
if(jComboBox3.getSelectedIndex()==0){
emg=Integer.parseInt(jTextField20.getText());
list1.add(emg);
}
else if(jComboBox3.getSelectedIndex()==1){
list2.add(jTextField20.getText());
}
else if(jComboBox3.getSelectedIndex()==2){
list3.add(jTextField20.getText());
}
}
public void Date(){
day=jTextField23.getText();
jTextField7.setText(day);
}
public void occupation(){
cls=jTextField44.getText();
jTextField15.setText(cls);
}
public void count(){
jTextField20.setText(Integer.toString(count));
}
public void fulllevel1(){
jTextField25.setText("level1_Full");
}
public void fulllevel2(){
jTextField25.setText("level2_Full");
}
public void fulllevel3(){
jTextField25.setText("Level3_Full");
}
public void Level(){
if(jComboBox2.getSelectedIndex()==0){
jTextField9.setText("Level 1");
}
else if(jComboBox2.getSelectedIndex()==1){
jTextField9.setText("Level 2");
}
else if(jComboBox2.getSelectedIndex()==2){
jTextField9.setText("Level 3");
}
}
public void Age(){
clas=jTextField43.getText();
jTextField13.setText(clas);
}
public void Sex(){
if(jComboBox1.getSelectedIndex()==0){
jTextField17.setText("Male");
}else if(jComboBox1.getSelectedIndex()==1)
{
jTextField17.setText("Female");
}
}
public void Name(){
name=jTextField42.getText();
jTextField11.setText(name);   
}
public void Payment(){
if(jComboBox2.getSelectedIndex()==0){
jTextField19.setText("50 Birr/Day");
}
else if(jComboBox2.getSelectedIndex()==1){
jTextField19.setText("30 Birr/Day");
}
else if(jComboBox2.getSelectedIndex()==2){
jTextField19.setText("20 Birr/Day");
}
}
public void Reserve()
    {
        if ( jComboBox2.getSelectedIndex() == 0 )
        {
            firstlevel();
        }
        else if(jComboBox2.getSelectedIndex()== 1)
        {
            secondlevel();
        }
         else if(jComboBox2.getSelectedIndex()== 2)
        {
            thirdlevel();
        }
    }

 public void firstlevel() // 
    {
        for ( count = 1; count <= 10; count++ )
        {
            if ( Assignbed[count] == false )  // if false, then a bed available for assignment
            {
                Assignbed[count] = true;  // assign bed
                count();
                break;
            }
            else if ( Assignbed[10] == true ) // If assignedbed[10] is true then first level is full
            {
                fulllevel1();

            }
        }
    }   

 public void secondlevel() //
    {
        for ( count = 11; count <= 20; count++ )
        {
            if ( Assignbed[count] == false ) //
            {
                Assignbed[count] = true; //
               count();
                break;
            }
            else if ( Assignbed[20] == true ) // 
            {
                fulllevel2();

            }
        }
    }
  public void thirdlevel() // 
    {
        for ( count = 21; count <= 30; count++ )
        {
            if ( Assignbed[count] == false ) 
            {
               Assignbed[count] = true;
               count();
                break;
            }
            else if ( Assignbed[30] == true ) 
            {
                fulllevel3();

            }
        }
    }

    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        /* Create and display the form */
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new Patient().setVisible(true);
            }
        });
    }


}

第二课

import java.util.ArrayList;
public class Staff extends javax.swing.JFrame {
private Patient p;
    public Staff() {
        initComponents();
    }                      

    private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {                                         
    Department1();
    }                                        
    public ArrayList<Integer> Department1(){
    p=new Patient();
    ArrayList<Integer> list1 = p.getList();  
        return list1;
    } 
    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new Staff().setVisible(true);
            }
        });
    }

}

Answer 1

你的问题在这里：

p=new Patient();  // ***** here *****
ArrayList<Integer> list1 = p.getList();

您正在创建新患者对象，并希望它与原始患者对象具有相同的状态。不要这样做 - 而是将原始患者（即保存感兴趣的数据的患者）的引用传递到新的类中：

import java.util.ArrayList;

public class Staff extends javax.swing.JFrame {
    private Patient p;

    public Staff(Patient p) {
        this.p = p;
        initComponents();
    }                      

    private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {                                         
        Department1();
    }                                        

    public ArrayList<Integer> Department1(){
        // p=new Patient();
        ArrayList<Integer> list1 = p.getList();  
        return list1;
    }

无论你做什么，请忽略任何告诉你让列表静态的人，因为这样做，你将忽略所有面向对象的编程原则。

Answer 2

您可以将其声明为static并使用简单的类名称点变量名称来访问它，或者创建get函数，如：

public List getList(){
    return <yourList>'
}

java Gui从另一个类访问arrayList

2 个答案: