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标题: 一个代码疑问 以前遗留下的问题 望解决 [打印本页]

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作者: che201311    时间: 2013-11-22 17:17
标题: 一个代码疑问 以前遗留下的问题 望解决
Java code
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class Initable {
  static final int staticFinal = 47;
  static final int staticFinal2 =ClassInitialization.rand.nextInt(1000);
  static {
    System.out.println("Initializing Initable");
  }
}
class Initable2 {
  static int staticNonFinal = 147;
  static {
    System.out.println("Initializing Initable2");
  }
}

class Initable3 {
  static int staticNonFinal = 74;
  static {
    System.out.println("Initializing Initable3");
  }
}

public class ClassInitialization {
  public static Random rand = new Random(47);
  public static void main(String[] args) throws Exception {
    Class initable = Initable.class;
    System.out.println("After creating Initable ref");
    // Does not trigger initialization:
    System.out.println(Initable.staticFinal);
    // Does trigger initialization:
    System.out.println(Initable.staticFinal2);
    // Does trigger initialization:
    System.out.println(Initable2.staticNonFinal);
    Class initable3 = Class.forName("Initable3");
    System.out.println("After creating Initable3 ref");
    System.out.println(Initable3.staticNonFinal);
  }
}


运行结果报错：After creating Initable ref
47
Initializing Initable
258
Initializing Initable2
147
Exception in thread "main" java.lang.ClassNotFoundException: Initable3
at java.net.URLClassLoader$1.run(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at aaaa.ClassInitialization.main(ClassInitialization.java:38)
为什么？为什么？

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作者: 何丛    时间: 2013-11-22 18:30
Class initable3 = Class.forName("Initable3");  
这一句传入的字符串必须是完整的路径名，包名.类名

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