001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache license, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the license for the specific language governing permissions and
015 * limitations under the license.
016 */
017package org.apache.log4j.builders.appender;
018
019import static org.apache.log4j.builders.BuilderManager.CATEGORY;
020import static org.apache.log4j.config.Log4j1Configuration.THRESHOLD_PARAM;
021import static org.apache.log4j.xml.XmlConfiguration.FILTER_TAG;
022import static org.apache.log4j.xml.XmlConfiguration.LAYOUT_TAG;
023import static org.apache.log4j.xml.XmlConfiguration.NAME_ATTR;
024import static org.apache.log4j.xml.XmlConfiguration.PARAM_TAG;
025import static org.apache.log4j.xml.XmlConfiguration.VALUE_ATTR;
026import static org.apache.log4j.xml.XmlConfiguration.forEachElement;
027
028import java.util.ArrayList;
029import java.util.List;
030import java.util.Properties;
031import java.util.concurrent.atomic.AtomicReference;
032
033import org.apache.log4j.Appender;
034import org.apache.log4j.Layout;
035import org.apache.log4j.bridge.AppenderWrapper;
036import org.apache.log4j.bridge.LayoutAdapter;
037import org.apache.log4j.bridge.LayoutWrapper;
038import org.apache.log4j.builders.AbstractBuilder;
039import org.apache.log4j.config.Log4j1Configuration;
040import org.apache.log4j.config.PropertiesConfiguration;
041import org.apache.log4j.spi.Filter;
042import org.apache.log4j.xml.XmlConfiguration;
043import org.apache.logging.log4j.Logger;
044import org.apache.logging.log4j.core.appender.ConsoleAppender;
045import org.apache.logging.log4j.core.config.plugins.Plugin;
046import org.apache.logging.log4j.status.StatusLogger;
047import org.w3c.dom.Element;
048
049/**
050 * Build a Console Appender
051 */
052@Plugin(name = "org.apache.log4j.ConsoleAppender", category = CATEGORY)
053public class ConsoleAppenderBuilder extends AbstractBuilder implements AppenderBuilder {
054    private static final String SYSTEM_OUT = "System.out";
055    private static final String SYSTEM_ERR = "System.err";
056    private static final String TARGET = "target";
057
058    private static final Logger LOGGER = StatusLogger.getLogger();
059
060    public ConsoleAppenderBuilder() {
061    }
062
063    public ConsoleAppenderBuilder(String prefix, Properties props) {
064        super(prefix, props);
065    }
066
067    @Override
068    public Appender parseAppender(final Element appenderElement, final XmlConfiguration config) {
069        String name = appenderElement.getAttribute(NAME_ATTR);
070        AtomicReference<String> target = new AtomicReference<>(SYSTEM_OUT);
071        AtomicReference<Layout> layout = new AtomicReference<>();
072        AtomicReference<List<Filter>> filters = new AtomicReference<>(new ArrayList<>());
073        AtomicReference<String> level = new AtomicReference<>();
074        forEachElement(appenderElement.getChildNodes(), currentElement -> {
075            switch (currentElement.getTagName()) {
076                case LAYOUT_TAG:
077                    layout.set(config.parseLayout(currentElement));
078                    break;
079                case FILTER_TAG:
080                    filters.get().add(config.parseFilters(currentElement));
081                    break;
082                case PARAM_TAG: {
083                    switch (currentElement.getAttribute(NAME_ATTR)) {
084                        case TARGET: {
085                            String value = currentElement.getAttribute(VALUE_ATTR);
086                            if (value == null) {
087                                LOGGER.warn("No value supplied for target parameter. Defaulting to System.out.");
088                            } else {
089                                switch (value) {
090                                    case SYSTEM_OUT:
091                                        target.set(SYSTEM_OUT);
092                                        break;
093                                    case SYSTEM_ERR:
094                                        target.set(SYSTEM_ERR);
095                                        break;
096                                    default:
097                                        LOGGER.warn("Invalid value \"{}\" for target parameter. Using default of System.out",
098                                                value);
099                                }
100                            }
101                            break;
102                        }
103                        case THRESHOLD_PARAM: {
104                            String value = currentElement.getAttribute(VALUE_ATTR);
105                            if (value == null) {
106                                LOGGER.warn("No value supplied for Threshold parameter, ignoring.");
107                            } else {
108                                level.set(value);
109                            }
110                            break;
111                        }
112                    }
113                    break;
114                }
115            }
116        });
117        Filter head = null;
118        Filter current = null;
119        for (Filter f : filters.get()) {
120            if (head == null) {
121                head = f;
122            } else {
123                current.next = f;
124            }
125            current = f;
126        }
127        return createAppender(name, layout.get(), head, level.get(), target.get(), config);
128    }
129
130    @Override
131    public Appender parseAppender(final String name, final String appenderPrefix, final String layoutPrefix,
132            final String filterPrefix, final Properties props, final PropertiesConfiguration configuration) {
133        Layout layout = configuration.parseLayout(layoutPrefix, name, props);
134        Filter filter = configuration.parseAppenderFilters(props, filterPrefix, name);
135        String level = getProperty(THRESHOLD_PARAM);
136        String target = getProperty(TARGET);
137        return createAppender(name, layout, filter, level, target, configuration);
138    }
139
140    private <T extends Log4j1Configuration> Appender createAppender(String name, Layout layout, Filter filter,
141            String level, String target, T configuration) {
142        org.apache.logging.log4j.core.Layout<?> consoleLayout = null;
143
144        if (layout instanceof LayoutWrapper) {
145            consoleLayout = ((LayoutWrapper) layout).getLayout();
146        } else if (layout != null) {
147            consoleLayout = new LayoutAdapter(layout);
148        }
149        org.apache.logging.log4j.core.Filter consoleFilter = buildFilters(level, filter);
150        ConsoleAppender.Target consoleTarget = SYSTEM_ERR.equals(target)
151                ? ConsoleAppender.Target.SYSTEM_ERR : ConsoleAppender.Target.SYSTEM_OUT;
152        return new AppenderWrapper(ConsoleAppender.newBuilder()
153                .setName(name)
154                .setTarget(consoleTarget)
155                .setLayout(consoleLayout)
156                .setFilter(consoleFilter)
157                .setConfiguration(configuration)
158                .build());
159    }
160}