这是我得到的错误代码：
Exception in thread "main" java.lang.StackOverflowError
at JavaKeywords.<init>(JavaKeywords.java:5)
at LAddClass.<init>(LAddClass.java:8)
at LStore.<init>(LStore.java:9)
at LAddClass.<init>(LAddClass.java:9)
at LStore.<init>(LStore.java:9)
以下是上述三个类别。很抱歉张贴几乎整个程序的代码，但我真的不知道错误在哪里。由错误代码掩盖的三行以下突出显示。
这是UML-toJava转换器的程序。用户必须输入类名称和类类型（公共/私有），并将变量存储在虚拟类中。我已经创建了一个类对象的ArrayList来存储用户的输入，即String className和boolean isPrivate。稍后，必须在GUI窗口中打印类名称和类型，以供用户复制文本。
我猜想该错误与未能将值（
String className, String classMethod, boolean isPrivate）存储到ArrayList<LStore>有关，后者是LStore类的对象的arrayList。之前我有一个Null Pointer Exception错误，该错误应该与arraylist有关，并且在我更改了一些代码和类名之后，我遇到了这个新的stackOverFlow错误。LAddClass class用于使用checkName()并将bolean isPrivate转换为字符串以供以后使用public class LAddClass{
private String className;
private String methodName;
private boolean isPrivate;
JavaKeywords keyObject = new JavaKeywords();
LStore stObject = new LStore(className, methodName,isPrivate);//<<<<<<<<<<<<<<<<<<<<<<<<<<< related to the error
public String getPublic(){
String s;
if (stObject.getIsPrivate() == true)
s = " private";
else
s = "public";
return s;
}
public void setPublic(){
}
public boolean checkName(String name){
boolean check = true;
for (int i=0; i<=stObject.getListSize(); i++){
if (keyObject.containsKeyword(name) || name.equals(stObject.getClassName())){
boolean o = false;
check = o;
}// end if
}// end for
return check;
}// end checkName
}//end class
LStore class是用于将变量存储到ArrayList<LStore>的类import java.util.*;
public class LStore {
public static ArrayList<LStore> classes = new ArrayList<LStore>();
public boolean isPrivate;
public String className;
public String methodName;
LAddClass classObject = new LAddClass(); //<<<<<<<<<<<<<<<<<<<<<<<<<<< related to the error
public LStore(String name, String method, boolean isP){
this.className = name;
this.isPrivate = isP;
this.methodName = method;
classes.add(this);
}
public String getClassName(){
return className;
}
public String getMethodName(){
return methodName;
}
public boolean getIsPrivate(){
return isPrivate;
}
public int getListSize(){
return classes.size();
}
public String getJavaCode(){
String javaCode = (classObject.getPublic() + " " + className +"{\n"+"\t"+methodName+"\t\n}"+"}");
return javaCode;
}
}
这里是GUI类
GuiAddClass，供用户创建新类。我认为它也可能包含一些错误，因此我将其作为参考。import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class GuiAddClass extends JFrame{
LAddClass classObject = new LAddClass();
private JRadioButton publicButton, privateButton;
private JLabel clazz;
private JTextField inputClassName;
private JLabel mothod;
private JTextField inputMethodName;
private JLabel note;
private JButton confirmButton;
private JButton cancelButton;
public GuiAddClass(){
super("Create class");
setLayout(new FlowLayout());
publicButton = new JRadioButton("public", false);
privateButton = new JRadioButton("private", true);
clazz = new JLabel("Class Name: ");
inputClassName = new JTextField("ExampleClass",10);
mothod = new JLabel("Method Name*: ");
inputMethodName = new JTextField("doSomething()",10);
note = new JLabel("*All methods are public void in default. You may only create one method for a class.");
confirmButton = new JButton("Confirm");
cancelButton = new JButton("Cancel");
add(publicButton);
add(privateButton);
add(clazz);
add(inputClassName);
add(mothod);
add(inputMethodName);
add(note);
add(confirmButton);
add(cancelButton);
ButtonGroup group = new ButtonGroup();
group.add(publicButton);
group.add(privateButton);
Handler handler = new Handler();
NewHandler newhandler = new NewHandler();
confirmButton.addActionListener(handler);
cancelButton.addActionListener(newhandler);
}// end constructor AddClass()
private class Handler implements ActionListener{
public void actionPerformed(ActionEvent event){
String cName = inputClassName.getText();
String mName = inputMethodName.getText();
boolean isP = true;
if (classObject.checkName(cName) == false){
JOptionPane.showMessageDialog(null, "Class name invalid. " +
"\nEntered name should not contain java keywords or equal to other existing names. " +
"\nPlease try again.");
} else if (classObject.checkName(cName) == true) {
JOptionPane.showMessageDialog(null, "Class saved.");
cName = inputClassName.getText();
mName = inputMethodName.getText();
if (event.getSource() == publicButton) {
isP = false;
} else if (event.getSource() == privateButton) {
isP = true;
}
new LStore(cName, mName, isP);
}
}// end actionPerformed()
}// end Handler class
private class NewHandler implements ActionListener{
public void actionPerformed(ActionEvent event){
setVisible(false);
}
}
}// end AddClass
JavaKeywords class最初来自How to check if the class name is valid?，这是一个具有检查className是否等于java保留关键字的方法的类。它也可能与错误有关，因为此类似乎经常被检测为错误import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashSet;
/**
* JavaKeywords is a Utility class related to the reserved keywords
*
* @author MrLore from https://stackoverflow.com/questions/13979172/how-to-check-if-the-class-name-is-valid
*/
public class JavaKeywords
{
private static final HashSet<String> keywords = new HashSet(Arrays.asList(new String[]{
//There are 50 keywords, and 3 literals; true, false and null.
"abstract", "assert", "boolean", "break", "byte",
"case", "catch", "char", "class", "const",
"continue", "default", "do", "double", "else",
"enum", "extends", "false", "final", "finally",
"float", "for", "goto", "if", "implements",
"import", "instanceof", "int", "interface", "long",
"native", "new", "null", "package", "private",
"protected", "public", "return", "short", "static",
"strictfp", "super", "switch", "synchronized", "this",
"throw", "throws", "transient", "true", "try",
"void", "volatile", "while" , "string", "int"
}));
public static boolean isKeyword(String toCheck){
return getKeywords().contains(toCheck);
}//End isKeyword()
public static String[] getAsArray(){
return getKeywords().toArray(new String[getKeywords().size()]);
}//End getAsArray()
public static ArrayList<String> getAsArrayList(){
return new ArrayList(getKeywords());
}//End getAsArrayList()
public static HashSet<String> getAsHashSet(){
return getKeywords();
}//End getAsHashSet()
public static HashSet<String> getKeywords() {
return keywords;
}//End getKeywords
public boolean containsKeyword(String toCheck){
toCheck = toCheck.toLowerCase(); //<<<<<<<<<<<<<<<<<<<<<<< this line had been detected as error of null-pointer-exception
for(String keyword : keywords){
if(toCheck.equals(keyword) || toCheck.endsWith("." + keyword) ||
toCheck.startsWith(keyword + ".") || toCheck.contains("." + keyword + ".")){
return true;
}//End if
}//End for
return false;
}//End containsKeyword()
}//End JavaKeywords
这就是所有的代码！！我的其他类只是与数据存储无关的GUI类，因此我想我不应该发布它们。感谢您阅读我的问题，如果您有任何想法，请帮助:(
最佳答案
您可以通过阅读stacktrace找到问题：
创建LJKeywords实例时出现问题（通过LJKeywords.<init>（LJKeywords.java:10）消息）。
创建LAddClass的实例时（通过LAddClass.<init>（LAddClass.java:8）消息），将发生这种情况。
创建LStore类的实例（通过LStore.<init>（LStore.java:9）消息）时，会发生这种情况。
然后，通过检查您的LAddClass和LStore类构造函数和字段，我发现：
public class LAddClass{
LJKeywords keyObject = new LJKeywords();
LStore stObject = new LStore(className, methodName,isPrivate);
//...
}
public class LStore {
LAddClass classObject = new LAddClass();
//...
}
那么，这是在做什么呢？创建
LStore对象引用时，它将在内部创建LAddClass对象引用，在内部将创建新的LStore对象引用，在内部将创建LAddClass对象引用，在内部...好，现在您知道要进行的操作，这里有一个无限的对象实例化循环。该怎么解决呢？删除此无限循环后，可以通过在客户端类中彼此分离并相互关联来创建
LAddClass和LStore。例如：class Client {
void foo() {
LAddClass lAddClass = new LAddClass();
LStore lStore = new LStore();
lStore.setLAddClass(lAddClass);
lAddClass.setLStore(lStore);
//...
}
}
另外，我建议将您的类的名称更改为更重要的名称。例如，使用
LStore代替Storage，使用LAddClass代替UMLClass（或更合适的名称）。