很奇怪的异常,大家帮看下

[jin2001jy]

Enter class name (e.g. java.util.Date):
ReflectionTest

用java.util.Date可以运行,用ReflectionTest就不行,大家帮忙看下,

java.lang.ClassNotFoundException: ReflectionTest
at java.net.URLClassLoader$1.run(URLClassLoader.java:200)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:268)
at java.lang.ClassLoader.loadClass(ClassLoader.java:251)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:164)
at study.ReflectionTest.main(ReflectionTest.java:24)


package study;

import java.util.*;
import java.lang.reflect.*;

public class ReflectionTest
{
public static void main(String[] args)
{
// read class name from command line args or user input
String name;
if (args.length > 0)
name = args[0];
else
{
Scanner in = new Scanner(System.in);
System.out.println("Enter class name (e.g. java.util.Date): ");
name = in.next();
}

try
{
// print class name and superclass name (if != Object)
Class cl = Class.forName(name);
Class supercl = cl.getSuperclass();
System.out.print("class " + name);
if (supercl != null && supercl != Object.class)
System.out.print(" extends " + supercl.getName());

System.out.print("\n{\n");
printConstructors(cl);
System.out.println();
printMethods(cl);
System.out.println();
printFields(cl);
System.out.println("}");
}
catch(ClassNotFoundException e) { e.printStackTrace(); }
System.exit(0);
}

public static void printConstructors(Class cl)
{
Constructor[] constructors = cl.getDeclaredConstructors();

for (Constructor c : constructors)
{
String name = c.getName();
System.out.print(" " + Modifier.toString(c.getModifiers()));
System.out.print(" " + name + "(");

// print parameter types
Class[] paramTypes = c.getParameterTypes();
for (int j = 0; j < paramTypes.length; j++)
{
if (j > 0) System.out.print(", ");
System.out.print(paramTypes[j].getName());
}
System.out.println(");");
}
}


public static void printMethods(Class cl)
{
Method[] methods = cl.getDeclaredMethods();

for (Method m : methods)
{
Class retType = m.getReturnType();
String name = m.getName();

// print modifiers, return type and method name
System.out.print(" " + Modifier.toString(m.getModifiers()));
System.out.print(" " + retType.getName() + " " + name + "(");

// print parameter types
Class[] paramTypes = m.getParameterTypes();
for (int j = 0; j < paramTypes.length; j++)
{
if (j > 0) System.out.print(", ");
System.out.print(paramTypes[j].getName());
}
System.out.println(");");
}
}


public static void printFields(Class cl)
{
Field[] fields = cl.getDeclaredFields();

for (Field f : fields)
{
Class type = f.getType();
String name = f.getName();
System.out.print(" " + Modifier.toString(f.getModifiers()));
System.out.println(" " + type.getName() + " " + name + ";");
}
}
}

[梦想家起飞]

你确定ReflectionTest在classpath上吗？

[jin2001jy]

之前这程序都没问题啊,就是今天拿来用就出问题了.我都没运什么啊

[jin2001jy]

呵呵,打错字,是没动什么......

[梦想家起飞]

cmd
echo %classpath%

执行结果贴上来看看。

[奋斗并快乐着]

输入的classname应该是完整名，包括包结构：study.ReflectionTest

[jin2001jy]

大家帮忙看下,哪里出了问题

[zoubinstef]

程序没问题。把包名加上就可以了。。。

[jin2001jy]

呵呵,程序OK了.谢谢大家

[jin2001jy]

.;D:\Program Files\Java\jdk1.5.0\lib\dt.jar;D:\Program Files\Java\jdk1.5.0\lib\
ools.jar


输入的classname应该是完整名，包括包结构：study.ReflectionTest.
这样也不行,我试过了.刚开始程序没问题时不用加study.都可以出结果的.