3

我目前正在创建一个库，旨在查看一堆字符串并用它们创建窗口。目前，只有几行代码和一个巨大的配置文件就会用很多窗口和东西来启动它。我将它设置为读取一些字符串并从中加载类，以获取方法的参数。这是执行此操作的方法：

    private Class<?> getClass(String classname){
        switch(classname){//Check for some primitive type references, since they don't work in the below area
            case "int":
                return int.class;
            case "double":
                return double.class;
            case "boolean":
                return boolean.class;
            case "long":
                return long.class;
            case "short":
                return short.class;
        }
        Class<?> value = null;
        try{
            value = Config.class.getClassLoader().loadClass(classname);
        }catch(ClassNotFoundException ex){
            Error.error(ErrorLevel.severe, "Could not find class- "+classname, ex, ErrorCatagory.classFinding);//A custom error handling system
        }
        return value;//Return the class found from the name
    }

它在普通课程上工作得很好。例如，如果我将 java.lang.String 放入其中，它会将 String 类吐回给我。如果我输入 javax.swing.JTextField，它会向我吐出正确的类。但是，如果我将 java.lang.String[] 放入其中以请求字符串数组，它会崩溃，如下所示：

    Warning in catagory code- message = Could not find suitable instance for method- Expected JTextComponent but found JTextField!
    Severe error in catagory classFinding
    May 16, 2012 11:02:35 AM ErrorAdapter severeError
    SEVERE: Could not find class- java.lang.String[]
    java.lang.ClassNotFoundException: java.lang.String[]
        at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
        at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:423)
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:356)
        at Config.getClass(Config.java:389)
        at Config.getClasses(Config.java:398)
        at Config.methodCall(Config.java:492)
        at Config.call(Config.java:415)
        at Config.chainCall(Config.java:439)
        at Config.call(Config.java:409)
        at main.action(main.java:122)
        at main$1$5.actionPerformed(main.java:63)
        at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
        at javax.swing.AbstractButton$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:6505)
        at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
        at java.awt.Component.processEvent(Component.java:6270)
        at java.awt.Container.processEvent(Container.java:2229)
        at java.awt.Component.dispatchEventImpl(Component.java:4861)
        at java.awt.Container.dispatchEventImpl(Container.java:2287)
        at java.awt.Component.dispatchEvent(Component.java:4687)
        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:2713)
        at java.awt.Component.dispatchEvent(Component.java:4687)
        at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:707)
        at java.awt.EventQueue.access$000(EventQueue.java:101)
        at java.awt.EventQueue$3.run(EventQueue.java:666)
        at java.awt.EventQueue$3.run(EventQueue.java:664)
        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:680)
        at java.awt.EventQueue$4.run(EventQueue.java:678)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:677)
        at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:211)
        at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:128)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:117)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:113)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:105)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:90)

第一行 - 以“警告”开头的行 - 是因为如果我尝试在 JTextField.class 上使用 Class.getDeclaredMethod() 来获取 getText() 方法，它喜欢崩溃。剩下的就是崩溃报告。

有没有办法我可以解决这个问题并让它适用于任何类/数组深度（所以它适用于 java.lang.String[]、javax.swing.JTextField[][][] 和 int[ ][] 没有硬编码）？

另外，附带说明一下，是否有更好的方法来获取基于字符串的原始类型的类？

4

4 回答 4

3

你有没有尝试过：

Class.forName("[Ljava.lang.String;"); 对于字符串数组？

http://docs.oracle.com/javase/6/docs/api/java/lang/Class.html#forName(java.lang.String ) http://java.dzone.com/news/obtaining-array-类-java-ref

于 2012-05-16T15:25:15.053 回答
2

[Ljava.lang.String;是类的运行时签名java.lang.String[]

System.out.println(String[].class.getName());
于 2012-05-16T15:23:04.090 回答
1

Array names are denoted differently in Java. You can modify your method as follows to process arrays:

private Class<?> getClass(String classname){
    switch(classname){//Check for some primitive type references, since they don't work in the below area
        case "int":
            return int.class;
        case "int[]":
            return int[].class;
        case "double":
            return double.class;
        case "double[]":
            return double[].class;
        case "boolean":
            return boolean.class;
        case "boolean[]":
            return boolean[].class;
        case "long":
            return long.class;
        case "long[]":
            return long[].class;
        case "short":
            return short.class;
        case "short[]":
            return short[].class;
        case "char":
            return char.class;
        case "char[]":
            return char[].class;
    }
    Class<?> value = null;
    int arrayLevel = 0;
    while (classname.endsWith("[]")) {
        classname = classname.substring(0, classname.length()-2);
        arrayLevel++;
    }
    while (arrayLevel-- != 0) {
        className = "[L" + className + ";";
    }
    try{
        value = Config.class.getClassLoader().loadClass(classname);
    }catch(ClassNotFoundException ex){
        Error.error(ErrorLevel.severe, "Could not find class- "+classname, ex, ErrorCatagory.classFinding);//A custom error handling system
    }
    return value;//Return the class found from the name
}
于 2012-05-16T15:32:44.773 回答
0

如果您正在创建一个库，请善待您的客户并使用 Collections 类而不是数组。

对于原始类型，您始终可以传递盒装版本（java.lang.Integer等）

于 2012-05-16T15:27:15.290 回答