我的 jPanel 上有几个 jComboBoxes 和 jTextFields。
选择并输入的值保存在文本文件中。
PrintWriter outfile = new PrintWriter(new BufferedWriter(new FileWriter...
outfile.write(jcb1.getSelectedItem().toString().substring(1, 8));
outfile.write(jTextField1.getText());
但是当我允许 jComboBoxes 为空时，我无法保存 jcb1 的空值并收到此错误:
Exception in thread "AWT-EventQueue-0" java.lang.StringIndexOutOfBoundsException: String index out of range: 8
at java.lang.String.substring(String.java:1907)
at main.panel.saveActionPerformed(panel.java:5929)
at main.panel.access$200(panel.java:36)
at main.panel$3.actionPerformed(panel.java:5713)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
at java.awt.Component.processMouseEvent(Component.java:6516)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3320)
at java.awt.Component.processEvent(Component.java:6281)
at java.awt.Container.processEvent(Container.java:2229)
at java.awt.Component.dispatchEventImpl(Component.java:4872)
at java.awt.Container.dispatchEventImpl(Container.java:2287)
at java.awt.Component.dispatchEvent(Component.java:4698)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4492)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
at java.awt.Container.dispatchEventImpl(Container.java:2273)
at java.awt.Window.dispatchEventImpl(Window.java:2719)
at java.awt.Component.dispatchEvent(Component.java:4698)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:735)
at java.awt.EventQueue.access$200(EventQueue.java:103)
at java.awt.EventQueue$3.run(EventQueue.java:694)
at java.awt.EventQueue$3.run(EventQueue.java:692)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
at java.awt.EventQueue$4.run(EventQueue.java:708)
at java.awt.EventQueue$4.run(EventQueue.java:706)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:705)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)
我想保存jComboBox的空值，但由于substring出现错误。我不知道如何避免这个问题。
任何帮助将不胜感激。
最佳答案
在获取子字符串之前，请检查字符串长度。
String test = "test12";
String subtest;
//long version
if(test.length() > 8){
subtest = test.substring(1, 8);
} else {
subtest = test.substring(1, test.length());
}
//short version
subtest = test.substring(1, test.length() > 8 ? 8 : test.length());
System.out.println(subtest); //Output: est12
关于java - 线程中的异常 "AWT-EventQueue-0"java.lang.StringIndexOutOfBoundsException : String index out of range: 8，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/30171218/