checkpasswordpermission.java

21天学通java的示例程序源代码

/*
 * CheckPasswordPermission.java
 */
package com.wrox.password;

import java.security.*;

/**
 * The CheckPasswordPermission class. It implements a simple permission
 * without target (name) or actions: you either have CheckPasswordPermission
 * or you don't.
 */
public class CheckPasswordPermission extends Permission {

  /**
   * Creates a new CheckPasswordPermission object.
   */
  public CheckPasswordPermission() {
    super("<CheckPasswordPermission>");
  }

  /**
   * Creates a new CheckPasswordPermission object. This constructor
   * exists for use by the <code>Policy</code> object to instantiate
   * new Permission objects.
   * @param name ignored
   * @param actions ignored.
   */
  public CheckPasswordPermission(String name, String actions) {
    this();
  }

  /**
   * Test for equality. Since every CheckPasswordPermission is equal
   * to any other, this simply tests if <code>obj</code> is a
   * CheckPasswordPermission.
   * @param obj The object to test equality for
   * @return <code>true</code> if obj is a CheckPasswordPermission
   */
  public boolean equals(Object obj) {
    return obj instanceof CheckPasswordPermission;
  } 

  /**
   * This permission does not support any actions.
   * @return The empty string.
   */
  public String getActions() {
    return "";
  } 

  /**
   * Tests if a Permission is implied. Since CheckPasswordPermissions
   * imply only each other, this is identical to equals(Object).
   * @see #equals(Object)
   */
  public boolean implies(Permission p) {
    return equals(p);
  } 

  /**
   * The hash code for this object. Since all CheckPasswordPermission
   * objects are equal, this returns the class' hashCode.
   * @return The hash code for this object.
   */
  public int hashCode() {
    return CheckPasswordPermission.class.hashCode();
  } 
}