org.b3log.latke.util.Callstacks.java Source code

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Here is the source code for org.b3log.latke.util.Callstacks.java

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/*
 * Copyright (c) 2009, 2010, 2011, 2012, B3log Team
 *
 * 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.
 */
package org.b3log.latke.util;

import java.util.logging.Level;
import java.util.logging.Logger;
import org.apache.commons.lang.StringUtils;

/**
 * Call stack utilities.
 * 
 * @author <a href="mailto:DL88250@gmail.com">Liang Ding</a>
 * @version 1.0.0.4, Apr 11, 2012
 */
public final class Callstacks {

    /**
     * Logger.
     */
    private static final Logger LOGGER = Logger.getLogger(Callstacks.class.getName());

    /**
     * Checks the current method is whether invoked by a caller specified by the given class name and method name.
     * 
     * @param className the given class name
     * @param methodName the given method name, "*" for matching all methods
     * @return {@code true} if it is invoked by the specified caller, returns {@code false} otherwise
     */
    public static boolean isCaller(final String className, final String methodName) {
        final Throwable throwable = new Throwable();
        final StackTraceElement[] stackElements = throwable.getStackTrace();

        if (null == stackElements) {
            LOGGER.log(Level.WARNING, "Empty call stack");

            return false;
        }

        final boolean matchAllMethod = "*".equals(methodName);

        for (int i = 1; i < stackElements.length; i++) {
            if (stackElements[i].getClassName().equals(className)) {
                return matchAllMethod ? true : stackElements[i].getMethodName().equals(methodName);
            }
        }

        return false;
    }

    /**
     * Prints call stack with the specified logging level.
     * 
     * @param logLevel the specified logging level
     * @param carePackages the specified packages to print, for example, ["org.b3log.latke", "org.b3log.solo"], {@code null} to care 
     * nothing
     * @param exceptablePackages the specified packages to skip, for example, ["com.sun", "java.io", "org.b3log.solo.filter"], 
     * {@code null} to skip nothing
     */
    public static void printCallstack(final Level logLevel, final String[] carePackages,
            final String[] exceptablePackages) {
        if (null == logLevel) {
            LOGGER.log(Level.WARNING, "Requires parameter[logLevel]");

            return;
        }

        final Throwable throwable = new Throwable();
        final StackTraceElement[] stackElements = throwable.getStackTrace();

        if (null == stackElements) {
            LOGGER.log(Level.WARNING, "Empty call stack");

            return;
        }

        final StringBuilder stackBuilder = new StringBuilder("CallStack [").append(Strings.LINE_SEPARATOR);

        for (int i = 1; i < stackElements.length; i++) {
            final String stackElemClassName = stackElements[i].getClassName();

            if (!StringUtils.startsWithAny(stackElemClassName, carePackages)
                    || StringUtils.startsWithAny(stackElemClassName, exceptablePackages)) {
                continue;
            }

            stackBuilder.append("    [className=").append(stackElements[i].getClassName()).append(", fileName=")
                    .append(stackElements[i].getFileName()).append(", lineNumber=")
                    .append(stackElements[i].getLineNumber()).append(", methodName=")
                    .append(stackElements[i].getMethodName()).append(']').append(Strings.LINE_SEPARATOR);
        }
        stackBuilder.append("], fullDepth=[").append(stackElements.length).append("]");

        LOGGER.log(logLevel, stackBuilder.toString());
    }

    /**
     * Private constructor.
     */
    private Callstacks() {
    }
}