Java VMStackWalker.getClassContext方法代码示例

import gnu.classpath.VMStackWalker; //导入方法依赖的package包/类
/**
 * Get a list of all the classes currently executing methods on the Java
 * stack.  getClassContext()[0] is the currently executing method (ie. the
 * class that CALLED getClassContext, not SecurityManager).
 *
 * @return an array of classes on the Java execution stack
 */
protected Class[] getClassContext()
{
  Class[] stack1 = VMStackWalker.getClassContext();
  Class[] stack2 = new Class[stack1.length - 1];
  System.arraycopy(stack1, 1, stack2, 0, stack1.length - 1);
  return stack2;
}
 

import gnu.classpath.VMStackWalker; //导入方法依赖的package包/类
/**
 * Load the class with the given name. This method tries to use the context
 * class loader first. If this fails, it searches for the suitable class
 * loader in the caller stack trace. This method is a central point where all
 * requests to find a class by name are delegated.
 */
static Class forName(String className)
{
  try
    {
      return Class.forName(className, true,
                           Thread.currentThread().getContextClassLoader());
    }
  catch (ClassNotFoundException nex)
    {
      /**
       * Returns the first user defined class loader on the call stack, or
       * null when no non-null class loader was found.
       */
      Class[] ctx = VMStackWalker.getClassContext();
      for (int i = 0; i < ctx.length; i++)
        {
          // Since we live in a class loaded by the bootstrap
          // class loader, getClassLoader is safe to call without
          // needing to be wrapped in a privileged action.
          ClassLoader cl = ctx[i].getClassLoader();
          try
            {
              if (cl != null)
                return Class.forName(className, true, cl);
            }
          catch (ClassNotFoundException nex2)
            {
              // Try next.
            }
        }
    }
  return null;
}
 

import gnu.classpath.VMStackWalker; //导入方法依赖的package包/类
/**
 * Load the class with the given name. This method tries to use the context
 * class loader first. If this fails, it searches for the suitable class
 * loader in the caller stack trace. This method is a central point where all
 * requests to find a class by name are delegated.
 */
public static Class forName(String className) throws ClassNotFoundException
{
  try
    {
      return Class.forName(className, true,
                           Thread.currentThread().getContextClassLoader());
    }
  catch (ClassNotFoundException nex)
    {
      /**
       * Returns the first user defined class loader on the call stack, or
       * null when no non-null class loader was found.
       */
      Class[] ctx = VMStackWalker.getClassContext();
      for (int i = 0; i < ctx.length; i++)
        {
          // Since we live in a class loaded by the bootstrap
          // class loader, getClassLoader is safe to call without
          // needing to be wrapped in a privileged action.
          ClassLoader cl = ctx[i].getClassLoader();
          try
            {
              if (cl != null)
                return Class.forName(className, true, cl);
            }
          catch (ClassNotFoundException nex2)
            {
              // Try next.
            }
        }
    }
  throw new ClassNotFoundException(className);
}
 

import gnu.classpath.VMStackWalker; //导入方法依赖的package包/类
/**
 * A stack-walking wrapper method used by the JSR 166 RI.
 */
public static Class getCallerClass(int depth)
{
  return VMStackWalker.getClassContext()[depth];
}
 

import gnu.classpath.VMStackWalker; //导入方法依赖的package包/类
/**
 * A stack-walking wrapper method used by the JSR 166 RI. 
 */
public static Class getCallerClass(int depth)
{
  return VMStackWalker.getClassContext()[depth];
}
 

import gnu.classpath.VMStackWalker; //导入方法依赖的package包/类
/**
 * This method must be included, as it is used by System.load(),
 * System.loadLibrary(). The reference implementation of this method uses
 * the getStackClassLoader() method. Returns the ClassLoader of the method
 * that called the caller. i.e. A.x() calls B.y() calls callerClassLoader(),
 * A's ClassLoader will be returned. Returns null for the bootstrap
 * ClassLoader.
 * 
 * @return a ClassLoader or null for the bootstrap ClassLoader
 */
static ClassLoader callerClassLoader() {
       Class[] classes = VMStackWalker.getClassContext();
       return classes[2].getClassLoader();
}