Apache Log4j Core Implementation provides the functional components of the logging system. Users are free to create their own plugins and include them in the logging configuration. Apache Log4j Core is a required module to use Apache Log4j.

Bytecode (Java 8) for Apache Log4j Core Implementation is provided in a separate JAR file like log4j-core-2.14.1.jar.

Source Code files for Apache Log4j API are provided in both binary packge like apache-log4j-2.14.1-bin.zip and source package like apache-log4j-2.14.1-src.zip. You can download them at Apache Log4j Website.

You can also browse Source Code files for Apache Log4j Core Implementation 2.14.1 below.

⏎ org/apache/logging/log4j/core/pattern/JAnsiTextRenderer.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.pattern;

import static org.fusesource.jansi.AnsiRenderer.Code.BG_RED;
import static org.fusesource.jansi.AnsiRenderer.Code.BOLD;
import static org.fusesource.jansi.AnsiRenderer.Code.RED;
import static org.fusesource.jansi.AnsiRenderer.Code.WHITE;
import static org.fusesource.jansi.AnsiRenderer.Code.YELLOW;

import java.util.Collections;
import java.util.HashMap;
import java.util.Locale;
import java.util.Map;

import org.apache.logging.log4j.status.StatusLogger;
import org.fusesource.jansi.Ansi;
import org.fusesource.jansi.AnsiRenderer;
import org.fusesource.jansi.AnsiRenderer.Code;

/**
 * Renders an input as ANSI escaped output.
 *
 * Uses the JAnsi rendering syntax as the default to render a message into an ANSI escaped string.
 *
 * The default syntax for embedded ANSI codes is:
 *
 * <pre>
 *   &#64;|<em>code</em>(,<em>code</em>)* <em>text</em>|@
 * </pre>
 *
 * For example, to render the message {@code "Hello"} in green, use:
 *
 * <pre>
 *   &#64;|green Hello|@
 * </pre>
 *
 * To render the message {@code "Hello"} in bold and red, use:
 *
 * <pre>
 *   &#64;|bold,red Warning!|@
 * </pre>
 *
 * You can also define custom style names in the configuration with the syntax:
 *
 * <pre>
 * %message{ansi}{StyleName=value(,value)*( StyleName=value(,value)*)*}%n
 * </pre>
 *
 * For example:
 *
 * <pre>
 * %message{ansi}{WarningStyle=red,bold KeyStyle=white ValueStyle=blue}%n
 * </pre>
 *
 * The call site can look like this:
 *
 * <pre>
 * logger.info("@|KeyStyle {}|@ = @|ValueStyle {}|@", entry.getKey(), entry.getValue());
 * </pre>
 *
 * Note: This class originally copied and then heavily modified code from JAnsi's AnsiRenderer (which is licensed as
 * Apache 2.0.)
 *
 * @see AnsiRenderer
 */
public final class JAnsiTextRenderer implements TextRenderer {

    public static final Map<String, Code[]> DefaultExceptionStyleMap;
    static final Map<String, Code[]> DefaultMessageStyleMap;
    private static final Map<String, Map<String, Code[]>> PrefedinedStyleMaps;

    private static void put(final Map<String, Code[]> map, final String name, final Code... codes) {
        map.put(name, codes);
    }

    static {
        final Map<String, Map<String, Code[]>> tempPreDefs = new HashMap<>();
        // Default style: Spock
        {
            // TODO Should the keys be in an enum?
            final Map<String, Code[]> map = new HashMap<>();
            put(map, "Prefix", WHITE);
            put(map, "Name", BG_RED, WHITE);
            put(map, "NameMessageSeparator", BG_RED, WHITE);
            put(map, "Message", BG_RED, WHITE, BOLD);
            put(map, "At", WHITE);
            put(map, "CauseLabel", WHITE);
            put(map, "Text", WHITE);
            put(map, "More", WHITE);
            put(map, "Suppressed", WHITE);
            // StackTraceElement
            put(map, "StackTraceElement.ClassName", YELLOW);
            put(map, "StackTraceElement.ClassMethodSeparator", YELLOW);
            put(map, "StackTraceElement.MethodName", YELLOW);
            put(map, "StackTraceElement.NativeMethod", YELLOW);
            put(map, "StackTraceElement.FileName", RED);
            put(map, "StackTraceElement.LineNumber", RED);
            put(map, "StackTraceElement.Container", RED);
            put(map, "StackTraceElement.ContainerSeparator", WHITE);
            put(map, "StackTraceElement.UnknownSource", RED);
            // ExtraClassInfo
            put(map, "ExtraClassInfo.Inexact", YELLOW);
            put(map, "ExtraClassInfo.Container", YELLOW);
            put(map, "ExtraClassInfo.ContainerSeparator", YELLOW);
            put(map, "ExtraClassInfo.Location", YELLOW);
            put(map, "ExtraClassInfo.Version", YELLOW);
            // Save
            DefaultExceptionStyleMap = Collections.unmodifiableMap(map);
            tempPreDefs.put("Spock", DefaultExceptionStyleMap);
        }
        // Style: Kirk
        {
            // TODO Should the keys be in an enum?
            final Map<String, Code[]> map = new HashMap<>();
            put(map, "Prefix", WHITE);
            put(map, "Name", BG_RED, YELLOW, BOLD);
            put(map, "NameMessageSeparator", BG_RED, YELLOW);
            put(map, "Message", BG_RED, WHITE, BOLD);
            put(map, "At", WHITE);
            put(map, "CauseLabel", WHITE);
            put(map, "Text", WHITE);
            put(map, "More", WHITE);
            put(map, "Suppressed", WHITE);
            // StackTraceElement
            put(map, "StackTraceElement.ClassName", BG_RED, WHITE);
            put(map, "StackTraceElement.ClassMethodSeparator", BG_RED, YELLOW);
            put(map, "StackTraceElement.MethodName", BG_RED, YELLOW);
            put(map, "StackTraceElement.NativeMethod", BG_RED, YELLOW);
            put(map, "StackTraceElement.FileName", RED);
            put(map, "StackTraceElement.LineNumber", RED);
            put(map, "StackTraceElement.Container", RED);
            put(map, "StackTraceElement.ContainerSeparator", WHITE);
            put(map, "StackTraceElement.UnknownSource", RED);
            // ExtraClassInfo
            put(map, "ExtraClassInfo.Inexact", YELLOW);
            put(map, "ExtraClassInfo.Container", WHITE);
            put(map, "ExtraClassInfo.ContainerSeparator", WHITE);
            put(map, "ExtraClassInfo.Location", YELLOW);
            put(map, "ExtraClassInfo.Version", YELLOW);
            // Save
            tempPreDefs.put("Kirk", Collections.unmodifiableMap(map));
        }
        {
            final Map<String, Code[]> temp = new HashMap<>();
            // TODO
            DefaultMessageStyleMap = Collections.unmodifiableMap(temp);
        }
        PrefedinedStyleMaps = Collections.unmodifiableMap(tempPreDefs);
    }

    private final String beginToken;
    private final int beginTokenLen;
    private final String endToken;
    private final int endTokenLen;
    private final Map<String, Code[]> styleMap;

    public JAnsiTextRenderer(final String[] formats, final Map<String, Code[]> defaultStyleMap) {
        String tempBeginToken = AnsiRenderer.BEGIN_TOKEN;
        String tempEndToken = AnsiRenderer.END_TOKEN;
        Map<String, Code[]> map;
        if (formats.length > 1) {
            final String allStylesStr = formats[1];
            // Style def split
            final String[] allStyleAssignmentsArr = allStylesStr.split(" ");
            map = new HashMap<>(allStyleAssignmentsArr.length + defaultStyleMap.size());
            map.putAll(defaultStyleMap);
            for (final String styleAssignmentStr : allStyleAssignmentsArr) {
                final String[] styleAssignmentArr = styleAssignmentStr.split("=");
                if (styleAssignmentArr.length != 2) {
                    StatusLogger.getLogger().warn("{} parsing style \"{}\", expected format: StyleName=Code(,Code)*",
                            getClass().getSimpleName(), styleAssignmentStr);
                } else {
                    final String styleName = styleAssignmentArr[0];
                    final String codeListStr = styleAssignmentArr[1];
                    final String[] codeNames = codeListStr.split(",");
                    if (codeNames.length == 0) {
                        StatusLogger.getLogger().warn(
                                "{} parsing style \"{}\", expected format: StyleName=Code(,Code)*",
                                getClass().getSimpleName(), styleAssignmentStr);
                    } else {
                        switch (styleName) {
                        case "BeginToken":
                            tempBeginToken = codeNames[0];
                            break;
                        case "EndToken":
                            tempEndToken = codeNames[0];
                            break;
                        case "StyleMapName":
                            final String predefinedMapName = codeNames[0];
                            final Map<String, Code[]> predefinedMap = PrefedinedStyleMaps.get(predefinedMapName);
                            if (predefinedMap != null) {
                                map.putAll(predefinedMap);
                            } else {
                                StatusLogger.getLogger().warn("Unknown predefined map name {}, pick one of {}",
                                        predefinedMapName, null);
                            }
                            break;
                        default:
                            final Code[] codes = new Code[codeNames.length];
                            for (int i = 0; i < codes.length; i++) {
                                codes[i] = toCode(codeNames[i]);
                            }
                            map.put(styleName, codes);
                        }
                    }
                }
            }
        } else {
            map = defaultStyleMap;
        }
        styleMap = map;
        beginToken = tempBeginToken;
        endToken = tempEndToken;
        beginTokenLen = tempBeginToken.length();
        endTokenLen = tempEndToken.length();
    }

    public Map<String, Code[]> getStyleMap() {
        return styleMap;
    }

    private void render(final Ansi ansi, final Code code) {
        if (code.isColor()) {
            if (code.isBackground()) {
                ansi.bg(code.getColor());
            } else {
                ansi.fg(code.getColor());
            }
        } else if (code.isAttribute()) {
            ansi.a(code.getAttribute());
        }
    }

    private void render(final Ansi ansi, final Code... codes) {
        for (final Code code : codes) {
            render(ansi, code);
        }
    }

    /**
     * Renders the given text with the given names which can be ANSI code names or Log4j style names.
     *
     * @param text
     *            The text to render
     * @param names
     *            ANSI code names or Log4j style names.
     * @return A rendered string containing ANSI codes.
     */
    private String render(final String text, final String... names) {
        final Ansi ansi = Ansi.ansi();
        for (final String name : names) {
            final Code[] codes = styleMap.get(name);
            if (codes != null) {
                render(ansi, codes);
            } else {
                render(ansi, toCode(name));
            }
        }
        return ansi.a(text).reset().toString();
    }

    // EXACT COPY OF StringBuilder version of the method but typed as String for input
    @Override
    public void render(final String input, final StringBuilder output, final String styleName)
            throws IllegalArgumentException {
        output.append(render(input, styleName));
    }

    @Override
    public void render(final StringBuilder input, final StringBuilder output) throws IllegalArgumentException {
        int i = 0;
        int j, k;

        while (true) {
            j = input.indexOf(beginToken, i);
            if (j == -1) {
                if (i == 0) {
                    output.append(input);
                    return;
                }
                output.append(input.substring(i, input.length()));
                return;
            }
            output.append(input.substring(i, j));
            k = input.indexOf(endToken, j);

            if (k == -1) {
                output.append(input);
                return;
            }
            j += beginTokenLen;
            final String spec = input.substring(j, k);

            final String[] items = spec.split(AnsiRenderer.CODE_TEXT_SEPARATOR, 2);
            if (items.length == 1) {
                output.append(input);
                return;
            }
            final String replacement = render(items[1], items[0].split(","));

            output.append(replacement);

            i = k + endTokenLen;
        }
    }

    private Code toCode(final String name) {
        return Code.valueOf(name.toUpperCase(Locale.ENGLISH));
    }

    @Override
    public String toString() {
        return "JAnsiMessageRenderer [beginToken=" + beginToken + ", beginTokenLen=" + beginTokenLen + ", endToken="
                + endToken + ", endTokenLen=" + endTokenLen + ", styleMap=" + styleMap + "]";
    }

}

⏎ org/apache/logging/log4j/core/pattern/JAnsiTextRenderer.java

Or download all of them as a single archive file:

File name: log4j-core-2.14.1-sources.jar
File size: 1281358 bytes
Release date: 2021-03-06
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