log4j-core/src/main/java/org/apache/logging/log4j/core/impl/ExtendedStackTraceElement.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.apache.logging.log4j.core.impl;

import java.io.Serializable;

import org.apache.logging.log4j.core.pattern.PlainTextRenderer;
import org.apache.logging.log4j.core.pattern.TextRenderer;
import org.apache.logging.log4j.util.Strings;

/**
 * Wraps and extends the concept of the JRE's final class {@link StackTraceElement} by adding more location information.
 * <p>
 * Complements a StackTraceElement with:
 * </p>
 * <ul>
 * <li>exact: whether the class was obtained via {@link sun.reflect.Reflection#getCallerClass(int)}</li>
 * <li>location: a classpath element or a jar</li>
 * <li>version</li>
 * </ul>
 */
public final class ExtendedStackTraceElement implements Serializable {

    static final ExtendedStackTraceElement[] EMPTY_ARRAY = {};

    private static final long serialVersionUID = -2171069569241280505L;

    private final ExtendedClassInfo extraClassInfo;

    private final StackTraceElement stackTraceElement;

    public ExtendedStackTraceElement(final StackTraceElement stackTraceElement,
            final ExtendedClassInfo extraClassInfo) {
        this.stackTraceElement = stackTraceElement;
        this.extraClassInfo = extraClassInfo;
    }

    /**
     * Called from Jackson for XML and JSON IO.
     */
    public ExtendedStackTraceElement(final String declaringClass, final String methodName, final String fileName,
            final int lineNumber, final boolean exact, final String location, final String version) {
        this(new StackTraceElement(declaringClass, methodName, fileName, lineNumber),
                new ExtendedClassInfo(exact, location, version));
    }

    /**
     * Called from Jackson for XML and JSON IO.
     */
    public ExtendedStackTraceElement(final String classLoaderName, final String moduleName, final String moduleVersion,
            final String declaringClass, final String methodName, final String fileName, final int lineNumber,
            final boolean exact, final String location, final String version) {
        this(new StackTraceElement(classLoaderName, moduleName, moduleVersion, declaringClass, methodName, fileName,
                        lineNumber),
                new ExtendedClassInfo(exact, location, version));
    }

    @Override
    public boolean equals(final Object obj) {
        if (this == obj) {
            return true;
        }
        if (obj == null) {
            return false;
        }
        if (!(obj instanceof ExtendedStackTraceElement)) {
            return false;
        }
        final ExtendedStackTraceElement other = (ExtendedStackTraceElement) obj;
        if (this.extraClassInfo == null) {
            if (other.extraClassInfo != null) {
                return false;
            }
        } else if (!this.extraClassInfo.equals(other.extraClassInfo)) {
            return false;
        }
        if (this.stackTraceElement == null) {
            if (other.stackTraceElement != null) {
                return false;
            }
        } else if (!this.stackTraceElement.equals(other.stackTraceElement)) {
            return false;
        }
        return true;
    }

    public String getClassLoaderName() {
        return this.stackTraceElement.getClassLoaderName();
    }

    public String getModuleName() {
        return this.stackTraceElement.getModuleName();
    }

    public String getModuleVersion() {
        return this.stackTraceElement.getModuleVersion();
    }

    public String getClassName() {
        return this.stackTraceElement.getClassName();
    }

    public boolean getExact() {
        return this.extraClassInfo.getExact();
    }

    public ExtendedClassInfo getExtraClassInfo() {
        return this.extraClassInfo;
    }

    public String getFileName() {
        return this.stackTraceElement.getFileName();
    }

    public int getLineNumber() {
        return this.stackTraceElement.getLineNumber();
    }

    public String getLocation() {
        return this.extraClassInfo.getLocation();
    }

    public String getMethodName() {
        return this.stackTraceElement.getMethodName();
    }

    public StackTraceElement getStackTraceElement() {
        return this.stackTraceElement;
    }

    public String getVersion() {
        return this.extraClassInfo.getVersion();
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((this.extraClassInfo == null) ? 0 : this.extraClassInfo.hashCode());
        result = prime * result + ((this.stackTraceElement == null) ? 0 : this.stackTraceElement.hashCode());
        return result;
    }

    public boolean isNativeMethod() {
        return this.stackTraceElement.isNativeMethod();
    }

    void renderOn(final StringBuilder output, final TextRenderer textRenderer) {
        render(this.stackTraceElement, output, textRenderer);
        textRenderer.render(" ", output, "Text");
        this.extraClassInfo.renderOn(output, textRenderer);
    }

    private void render(final StackTraceElement stElement, final StringBuilder output, final TextRenderer textRenderer) {
        final String fileName = stElement.getFileName();
        final int lineNumber = stElement.getLineNumber();
        final String moduleName = getModuleName();
        final String moduleVersion = getModuleVersion();
        if (Strings.isNotEmpty(moduleName)) {
            textRenderer.render(moduleName, output, "StackTraceElement.ModuleName");
            if (Strings.isNotEmpty(moduleVersion) && !moduleName.startsWith("java")) {
                textRenderer.render("@", output, "StackTraceElement.ModuleVersionSeparator");
                textRenderer.render(moduleVersion, output, "StackTraceElement.ModuleVersion");
            }
            textRenderer.render("/", output, "StackTraceElement.ModuleNameSeparator");
        }
        textRenderer.render(getClassName(), output, "StackTraceElement.ClassName");
        textRenderer.render(".", output, "StackTraceElement.ClassMethodSeparator");
        textRenderer.render(stElement.getMethodName(), output, "StackTraceElement.MethodName");
        if (stElement.isNativeMethod()) {
            textRenderer.render("(Native Method)", output, "StackTraceElement.NativeMethod");
        } else if (fileName != null && lineNumber >= 0) {
            textRenderer.render("(", output, "StackTraceElement.Container");
            textRenderer.render(fileName, output, "StackTraceElement.FileName");
            textRenderer.render(":", output, "StackTraceElement.ContainerSeparator");
            textRenderer.render(Integer.toString(lineNumber), output, "StackTraceElement.LineNumber");
            textRenderer.render(")", output, "StackTraceElement.Container");
        } else if (fileName != null) {
            textRenderer.render("(", output, "StackTraceElement.Container");
            textRenderer.render(fileName, output, "StackTraceElement.FileName");
            textRenderer.render(")", output, "StackTraceElement.Container");
        } else {
            textRenderer.render("(", output, "StackTraceElement.Container");
            textRenderer.render("Unknown Source", output, "StackTraceElement.UnknownSource");
            textRenderer.render(")", output, "StackTraceElement.Container");
        }
    }

    @Override
    public String toString() {
        final StringBuilder sb = new StringBuilder();
        renderOn(sb, PlainTextRenderer.getInstance());
        return sb.toString();
    }

}