我正在尝试用Java编写一个简单的Photoviewer。
我想将控制方法和设计分为两类（'Viewer'和'ViewerControls）。 要访问彼此的方法或变量，我必须创建每个的实例（我认为），这当然会引导我进入创建实例的无限循环，最后是一个stackoverflow异常。
所以我知道问题是什么，但不知道如何修复它。有人可以帮帮我吗？
观众代码：
public class Viewer extends javax.swing.JFrame {
/**
* Creates new form viewer
*/
public Viewer() {
initComponents();
}
/**
* This method is called from within the constructor to initialize the form.
* WARNING: Do NOT modify this code. The content of this method is always
* regenerated by the Form Editor.
*/
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
choosePnl = new javax.swing.JPanel();
chooseWindow = new javax.swing.JFileChooser();
buttonPnl = new javax.swing.JPanel();
prevBtn = new javax.swing.JButton();
playBtn = new javax.swing.JButton();
nextBtn = new javax.swing.JButton();
jPanel2 = new javax.swing.JPanel();
choose = new javax.swing.JButton();
jScrollPane1 = new javax.swing.JScrollPane();
jList1 = new javax.swing.JList<>();
lm = new DefaultListModel();
jList1.setModel(lm);
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
getContentPane().setLayout(new org.netbeans.lib.awtextra.AbsoluteLayout());
choosePnl.setVisible(false);
javax.swing.GroupLayout choosePnlLayout = new javax.swing.GroupLayout(choosePnl);
choosePnl.setLayout(choosePnlLayout);
choosePnlLayout.setHorizontalGroup(
choosePnlLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(chooseWindow, javax.swing.GroupLayout.DEFAULT_SIZE, 660, Short.MAX_VALUE)
);
choosePnlLayout.setVerticalGroup(
choosePnlLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(choosePnlLayout.createSequentialGroup()
.addComponent(chooseWindow, javax.swing.GroupLayout.PREFERRED_SIZE, 462, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(0, 18, Short.MAX_VALUE))
);
getContentPane().add(choosePnl, new org.netbeans.lib.awtextra.AbsoluteConstraints(0, 0, 660, 480));
buttonPnl.setBorder(javax.swing.BorderFactory.createBevelBorder(javax.swing.border.BevelBorder.RAISED));
prevBtn.setText("Prev");
prevBtn.setCursor(new java.awt.Cursor(java.awt.Cursor.HAND_CURSOR));
prevBtn.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
prevBtnActionPerformed(evt);
}
});
playBtn.setText("Play");
playBtn.setCursor(new java.awt.Cursor(java.awt.Cursor.HAND_CURSOR));
nextBtn.setText("Next");
nextBtn.setCursor(new java.awt.Cursor(java.awt.Cursor.HAND_CURSOR));
nextBtn.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
nextBtnActionPerformed(evt);
}
});
javax.swing.GroupLayout buttonPnlLayout = new javax.swing.GroupLayout(buttonPnl);
buttonPnl.setLayout(buttonPnlLayout);
buttonPnlLayout.setHorizontalGroup(
buttonPnlLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(buttonPnlLayout.createSequentialGroup()
.addContainerGap()
.addComponent(prevBtn, javax.swing.GroupLayout.PREFERRED_SIZE, 150, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(84, 84, 84)
.addComponent(playBtn, javax.swing.GroupLayout.PREFERRED_SIZE, 152, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(75, 75, 75)
.addComponent(nextBtn, javax.swing.GroupLayout.PREFERRED_SIZE, 152, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(23, Short.MAX_VALUE))
);
buttonPnlLayout.setVerticalGroup(
buttonPnlLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, buttonPnlLayout.createSequentialGroup()
.addContainerGap()
.addGroup(buttonPnlLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
.addComponent(nextBtn, javax.swing.GroupLayout.DEFAULT_SIZE, 54, Short.MAX_VALUE)
.addComponent(playBtn, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(prevBtn, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
.addContainerGap())
);
getContentPane().add(buttonPnl, new org.netbeans.lib.awtextra.AbsoluteConstraints(10, 480, 650, 80));
jPanel2.setBorder(javax.swing.BorderFactory.createBevelBorder(javax.swing.border.BevelBorder.RAISED));
choose.setText("Choose Folder");
choose.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
chooseActionPerformed(evt);
}
});
jScrollPane1.setFocusTraversalPolicyProvider(true);
jList1.setCursor(new java.awt.Cursor(java.awt.Cursor.DEFAULT_CURSOR));
jScrollPane1.setViewportView(jList1);
javax.swing.GroupLayout jPanel2Layout = new javax.swing.GroupLayout(jPanel2);
jPanel2.setLayout(jPanel2Layout);
jPanel2Layout.setHorizontalGroup(
jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel2Layout.createSequentialGroup()
.addContainerGap(22, Short.MAX_VALUE)
.addComponent(choose, javax.swing.GroupLayout.PREFERRED_SIZE, 180, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(24, 24, 24))
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel2Layout.createSequentialGroup()
.addContainerGap()
.addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 0, Short.MAX_VALUE)
.addContainerGap())
);
jPanel2Layout.setVerticalGroup(
jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel2Layout.createSequentialGroup()
.addComponent(choose, javax.swing.GroupLayout.PREFERRED_SIZE, 70, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 9, Short.MAX_VALUE)
.addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 476, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap())
);
getContentPane().add(jPanel2, new org.netbeans.lib.awtextra.AbsoluteConstraints(660, 0, 230, 570));
pack();
}// </editor-fold>
private void chooseActionPerformed(java.awt.event.ActionEvent evt) {
if (evt.getSource() == choose) {
choosePnl.setVisible(true);
chooseWindow.setMultiSelectionEnabled(true);
chooseWindow.showOpenDialog(null);
File[] selectedFiles = chooseWindow.getSelectedFiles();
for (File f : selectedFiles) {
lm.addElement(f.getPath());
}
listIndex = lm.getSize() - 1;
}
}
private void prevBtnActionPerformed(java.awt.event.ActionEvent evt) {
controls.previous();
}
private void nextBtnActionPerformed(java.awt.event.ActionEvent evt) {
controls.next();
}
public int getListIndex(){
return listIndex;
}
public void setListIndex(int index){
this.listIndex = index;
}
public static void main(String args[]) {
/* Set the Nimbus look and feel */
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new Viewer().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JPanel buttonPnl;
private javax.swing.JButton choose;
private javax.swing.JPanel choosePnl;
private javax.swing.JFileChooser chooseWindow;
private javax.swing.JList<String> jList1;
private javax.swing.JPanel jPanel2;
private javax.swing.JScrollPane jScrollPane1;
private javax.swing.JButton nextBtn;
private javax.swing.JButton playBtn;
private javax.swing.JButton prevBtn;
// End of variables declaration
private DefaultListModel lm;
private int listIndex;
ViewerControls controls = new ViewerControls();
}
ViewerControls代码：
public class ViewerControls {
Viewer viewer = new Viewer();
public void next(){
viewer.setListIndex(viewer.getListIndex()+ 1);
}
public void previous(){
viewer.setListIndex(viewer.getListIndex()- 1);
}
}
请记住，这是正在进行的工作，我是初学者，所以忽略其他错误。
先谢谢。