Java example source code file (SecurityManager.c)

This example Java source code file (SecurityManager.c) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

java_java_lang_securitymanager_classdepth, java_java_lang_securitymanager_classloaderdepth0, java_java_lang_securitymanager_currentclassloader0, java_java_lang_securitymanager_getclasscontext, jni_false, jni_true, jnicall, jniexport, jnu_thrownullpointerexception, jvm_classdepth, jvm_classloaderdepth, jvm_currentloadedclass, jvm_getclasscontext, null

The SecurityManager.c Java example source code

/*
 * Copyright (c) 1995, 2013, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

#include "jni.h"
#include "jni_util.h"
#include "jvm.h"

#include "java_lang_SecurityManager.h"
#include "java_lang_ClassLoader.h"

/*
 * Make sure a security manager instance is initialized.
 * TRUE means OK, FALSE means not.
 */
static jboolean
check(JNIEnv *env, jobject this)
{
    static jfieldID initField = 0;
    jboolean initialized = JNI_FALSE;

    if (initField == 0) {
        jclass clazz = (*env)->FindClass(env, "java/lang/SecurityManager");
        if (clazz == 0) {
            (*env)->ExceptionClear(env);
            return JNI_FALSE;
        }
        initField = (*env)->GetFieldID(env, clazz, "initialized", "Z");
        if (initField == 0) {
            (*env)->ExceptionClear(env);
            return JNI_FALSE;
        }
    }
    initialized = (*env)->GetBooleanField(env, this, initField);

    if (initialized == JNI_TRUE) {
        return JNI_TRUE;
    } else {
        jclass securityException =
            (*env)->FindClass(env, "java/lang/SecurityException");
        if (securityException != 0) {
            (*env)->ThrowNew(env, securityException,
                             "security manager not initialized.");
        }
        return JNI_FALSE;
    }
}

JNIEXPORT jobjectArray JNICALL
Java_java_lang_SecurityManager_getClassContext(JNIEnv *env, jobject this)
{
    if (!check(env, this)) {
        return NULL;            /* exception */
    }

    return JVM_GetClassContext(env);
}

JNIEXPORT jclass JNICALL
Java_java_lang_SecurityManager_currentLoadedClass0(JNIEnv *env, jobject this)
{
    /* Make sure the security manager instance is initialized */
    if (!check(env, this)) {
        return NULL;            /* exception */
    }

    return JVM_CurrentLoadedClass(env);
}

JNIEXPORT jobject JNICALL
Java_java_lang_SecurityManager_currentClassLoader0(JNIEnv *env, jobject this)
{
    /* Make sure the security manager instance is initialized */
    if (!check(env, this)) {
        return NULL;            /* exception */
    }

    return JVM_CurrentClassLoader(env);
}

JNIEXPORT jint JNICALL
Java_java_lang_SecurityManager_classDepth(JNIEnv *env, jobject this,
                                          jstring name)
{
    /* Make sure the security manager instance is initialized */
    if (!check(env, this)) {
        return -1;              /* exception */
    }

    if (name == NULL) {
      JNU_ThrowNullPointerException(env, 0);
      return -1;
    }

    return JVM_ClassDepth(env, name);
}

JNIEXPORT jint JNICALL
Java_java_lang_SecurityManager_classLoaderDepth0(JNIEnv *env, jobject this)
{
    /* Make sure the security manager instance is initialized */
    if (!check(env, this)) {
        return -1;              /* exception */
    }

    return JVM_ClassLoaderDepth(env);
}