Here you can find the source of canGetSubject()
static boolean canGetSubject()
//package com.java2s; /*/*from www .j av a 2s . c o m*/ * * Copyright 2005 Sun Microsystems, Inc. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * */ import javax.security.auth.AuthPermission; public class Main { /** * Test whether the caller has AuthPermission("getSubject"). * * @return true if the caller has AuthPermission("getSubject"), * false otherwise. */ static boolean canGetSubject() { try { SecurityManager sm = System.getSecurityManager(); if (sm != null) sm.checkPermission(new AuthPermission("getSubject")); return true; } catch (SecurityException e) { return false; } } }