Java 按键调用JInternalFrame返回NullException

我有一个JInternalFrame，当我在JTextField中按F1时，我想调用另一个JInternalFrame，但是我得到的是NullPointerException。这是我的密码

图形用户界面：

关键事件：

public void keyPressed(KeyEvent arg0) {
    // TODO Auto-generated method stub
    if( arg0.getKeyCode() == KeyEvent.VK_F1 ){
        listProducto.setVisible(true);******ERROR******
        Main.getInstance().getPortada().getDesktop().add(listProducto);
        Main.getInstance().getPortada().getDesktop()
                .moveToFront(listProducto);
        try {
            listProducto.setSelected(true);
        } catch (PropertyVetoException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}

---

问题是我忘记在initComponents（）中初始化searchForm

这是我丢失的代码

listProducto = new ListProducto();
    listProducto.addSearchEventListener(new searchEventListener() {
        public void resultFound(EventObject e) {
            listProductoSearchPerformed();
        }
    });

对于我的搜索，我创建了一个searchForm来处理searchListeners。我也添加了代码

package com.mbpe.search;

import java.beans.PropertyVetoException;
import java.util.ArrayList;
import java.util.Iterator;
import javax.swing.JInternalFrame;
import javax.swing.JInternalFrame;
import com.mbpe.gui.Portada;
import com.mbpe.main.Main;
import com.mbpe.main.searchEvent;
import com.mbpe.main.searchEventListener;



@SuppressWarnings("serial")
public class searchForm extends JInternalFrame {
public searchForm(String title, boolean resizable, boolean closable,
        boolean maximizable, boolean iconifiable) {
    super(title, resizable, closable, maximizable, iconifiable);
}

private List _listeners = new ArrayList();
public synchronized void addSearchEventListener(searchEventListener listener) {
    _listeners.add(listener);
}
public synchronized void removeSearchEventListener(searchEventListener listener) {
    _listeners.remove(listener);
}
public synchronized void fireEvent() {
    searchEvent event = new searchEvent(this);
    Iterator i = _listeners.iterator();
    while (i.hasNext()) {
        ((searchEventListener) i.next()).resultFound(event);
    }
}

public void onClose() {

}

public void onClosing() {
    dispose();
}

---

}

检查

listProducto

是否为

null

并添加完整的堆栈tracejust checked搜索表单初始化有问题。@LukasKnuth如果我已经找到解决方案，我能做什么？结束问题？？？。自己回答并解释错误是什么。

package com.mbpe.search;

import java.beans.PropertyVetoException;
import java.util.ArrayList;
import java.util.Iterator;
import javax.swing.JInternalFrame;
import javax.swing.JInternalFrame;
import com.mbpe.gui.Portada;
import com.mbpe.main.Main;
import com.mbpe.main.searchEvent;
import com.mbpe.main.searchEventListener;



@SuppressWarnings("serial")
public class searchForm extends JInternalFrame {
public searchForm(String title, boolean resizable, boolean closable,
        boolean maximizable, boolean iconifiable) {
    super(title, resizable, closable, maximizable, iconifiable);
}

private List _listeners = new ArrayList();
public synchronized void addSearchEventListener(searchEventListener listener) {
    _listeners.add(listener);
}
public synchronized void removeSearchEventListener(searchEventListener listener) {
    _listeners.remove(listener);
}
public synchronized void fireEvent() {
    searchEvent event = new searchEvent(this);
    Iterator i = _listeners.iterator();
    while (i.hasNext()) {
        ((searchEventListener) i.next()).resultFound(event);
    }
}

public void onClose() {

}

public void onClosing() {
    dispose();
}