/*
* Copyright (c) 2002-2012 Alibaba Group Holding Limited.
* All rights reserved.
*
* 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 com.alibaba.citrus.logconfig;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.net.InetAddress;
import java.net.URL;
import java.net.UnknownHostException;
import java.nio.charset.Charset;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.LinkedHashSet;
import java.util.Map;
import java.util.Properties;
import java.util.Set;
import java.util.TreeSet;
import org.slf4j.LoggerFactory;
/**
* 初始化日志，但不引入对特定日志系统的依赖。
*
* @author Michael Zhou
*/
public abstract class LogConfigurator {
private static final String PROVIDERS_PATTERN = "META-INF/logconfig.providers";
private static final String LOGGING_LEVEL = "loggingLevel";
private static final String LOGGING_CHARSET = "loggingCharset";
private static final String LOGGING_ROOT = "loggingRoot";
private static final String LOCAL_HOST = "localHost";
private static final String LOCAL_ADDRESS = "localAddress";
private String logSystem;
/**
* 用指定的配置文件来配置log system。
* <p/>
* 注意，即使配置过程失败，也不会抛出任何异常，只是打印错误信息。日志系统的失败不应该影响应用系统。
* <p/>
*/
public final void configure(URL configFile) {
configure(configFile, null);
}
/**
* 用指定的配置文件和properties来配置log system。
* <p/>
* 注意，即使配置过程失败，也不会抛出任何异常，只是打印错误信息。日志系统的失败不应该影响应用系统。
* <p/>
*/
public final void configure(URL configFile, Map<String, String> props) {
StringBuilder buf = new StringBuilder();
buf.append("INFO: configuring \"").append(logSystem).append("\" using ").append(configFile).append("\n");
if (props == null) {
props = new HashMap<String, String>();
}
for (String key : new TreeSet<String>(props.keySet())) {
String value = props.get(key);
// 以log开头的property，或者值与system properties不同的，打印出来。
if (key.startsWith("log") || value != null && !value.equals(System.getProperty(key))) {
buf.append(" - with property ").append(key).append(" = ").append(value).append("\n");
}
}
log(buf.toString());
try {
doConfigure(configFile, props);
} catch (Exception e) {
log("WARN: Failed to configure " + logSystem + " using " + configFile, e);
}
}
/**
* 用默认的配置文件和默认的properties来配置log system。
* <p>
* 相当于：
* <code>configure(getDefaultConfigFile(), getDefaultProperties());</code> 。
* </p>
*/
public final void configureDefault() {
configureDefault(null);
}
/**
* 用默认的配置文件和默认的properties来配置log system。
* <p>
* 相当于：
* <code>configure(getDefaultConfigFile(), getDefaultProperties(debug));</code>
* 。
* </p>
*/
public final void configureDefault(Boolean debug) {
URL configFile = getDefaultConfigFile();
if (configFile == null) {
log("ERROR: could not find default config file for \"" + logSystem + "\"");
return;
}
configure(configFile, getDefaultProperties(debug));
}
/** 取得当前configurator对应的log system的名称，例如：<code>logback</code>。 */
public final String getLogSystem() {
return logSystem;
}
/** 取得默认的配置文件URL。 */
public final URL getDefaultConfigFile() {
return getClass().getClassLoader().getResource(
getClass().getPackage().getName().replace('.', '/') + "/" + getDefaultConfigFileName());
}
/**
* 取得默认的配置文件名。
* <p>
* 子类可以覆盖此方法，以取得特定的配置文件。如不覆盖，默认返回<code>logsystem.xml</code>。
* </p>
*/
protected String getDefaultConfigFileName() {
return logSystem + "-default.xml";
}
/**
* 取得用于配置log system的默认的properties，包含以下内容：
* <ul>
* <li>system properties。</li>
* <li><code>loggingCharset</code> - 输出charset，取决于系统默认值。</li>
* <li><code>loggingLevel</code> - 日志level，取决于debug参数。</li>
* <li><code>loggingRoot</code> - 日志根目录，默认为<code>$HOME/logs</code>。</li>
* <li><code>localHost</code> - 当前机器名。</li>
* <li><code>localAddress</code> - 当前网址。</li>
* <li>子类可覆盖<code>setDefaultProperties()</code>方法，以便修改所设置的值。</li>
* </ul>
*/
public final Map<String, String> getDefaultProperties() {
return getDefaultProperties(null);
}
/**
* 取得用于配置log system的默认的properties，包含以下内容：
* <ul>
* <li>system properties。</li>
* <li><code>loggingCharset</code> - 输出charset，取决于系统默认值。</li>
* <li><code>loggingLevel</code> - 日志level，取决于debug参数。</li>
* <li><code>loggingRoot</code> - 日志根目录，默认为<code>$HOME/logs</code>。</li>
* <li><code>localHost</code> - 当前机器名。</li>
* <li><code>localAddress</code> - 当前网址。</li>
* <li>子类可覆盖<code>setDefaultProperties()</code>方法，以便修改所设置的值。</li>
* </ul>
*/
public final Map<String, String> getDefaultProperties(Boolean debug) {
Map<String, String> props = new HashMap<String, String>();
// system properties
for (Map.Entry<?, ?> entry : System.getProperties().entrySet()) {
props.put(String.valueOf(entry.getKey()), String.valueOf(entry.getValue()));
}
// charset
if (!isPropertyExist(props, LOGGING_CHARSET)) {
props.put(LOGGING_CHARSET, getDefaultCharset());
}
// level
if (!isPropertyExist(props, LOGGING_LEVEL)) {
if (debug == null) {
debug = false;
}
props.put(LOGGING_LEVEL, getDefaultLevel(debug));
}
// default logging root
if (!isPropertyExist(props, LOGGING_ROOT)) {
props.put(LOGGING_ROOT, getDefaultLoggingRoot());
}
// host info
String hostName;
String hostAddress;
try {
InetAddress localhost = InetAddress.getLocalHost();
hostName = localhost.getHostName();
hostAddress = localhost.getHostAddress();
} catch (UnknownHostException e) {
hostName = "localhost";
hostAddress = "127.0.0.1";
}
props.put(LOCAL_HOST, hostName);
props.put(LOCAL_ADDRESS, hostAddress);
// 给子类一个机会设置properties
setDefaultProperties(props);
return props;
}
private boolean isPropertyExist(Map<String, String> props, String name) {
return trimToNull(props.get(name)) != null;
}
private String getDefaultCharset() {
return Charset.defaultCharset().name();
}
private String getDefaultLevel(boolean debug) {
return debug ? "TRACE" : "INFO";
}
private String getDefaultLoggingRoot() {
return new File(System.getProperty("user.home") + "/logs").getAbsolutePath();
}
/**
* 设置默认的properties。
* <p>
* 子类可以覆盖它，以设置自己的默认值。
* </p>
*/
protected void setDefaultProperties(Map<String, String> props) {
}
/** 配置对应的log system，由子类实现。 */
protected abstract void doConfigure(URL configFile, Map<String, String> props) throws Exception;
/** 关闭和清理log system，由子类实现。 */
public abstract void shutdown();
/** 取得指定的日志系统配置器。假如未指定日志系统的名称，则试着从slf4j中自动取得当前可用的日志系统。 */
public static LogConfigurator getConfigurator() {
return getConfigurator((String) null);
}
/** 取得指定的日志系统配置器。假如未指定日志系统的名称，则试着从slf4j中自动取得当前可用的日志系统。 */
public static LogConfigurator getConfigurator(String logSystem) {
LogConfigurator[] configurators = getConfigurators(logSystem);
if (configurators == null || configurators.length == 0) {
return null;
} else {
return configurators[0];
}
}
/** 取得指定的日志系统配置器。假如未指定日志系统的名称，则试着从slf4j中自动取得当前可用的日志系统。 */
public static LogConfigurator[] getConfigurators(String... logSystems) {
ClassLoader cl = Thread.currentThread().getContextClassLoader();
Map<String, String> providers = getProviders(PROVIDERS_PATTERN, cl);
// 检查SLF4J所选择的日志系统
String slf4jLogSystem = guessSlf4jLogSystem(providers);
// 规格化所有logSystems
Set<String> logSystemToBeConfigured = new LinkedHashSet<String>();
if (logSystems == null || logSystems.length == 0) {
logSystems = new String[1];
}
boolean containsNull = false;
for (String logSystem : logSystems) {
if (logSystem != null) {
logSystem = trimToNull(logSystem.toLowerCase());
}
if (logSystem == null) {
logSystem = slf4jLogSystem;
}
if (logSystem == null) {
containsNull = true;
} else {
logSystemToBeConfigured.add(logSystem);
}
}
// 假如logSystems列表中未包含slf4jLogSystem，则报警。
if (slf4jLogSystem != null && !logSystemToBeConfigured.contains(slf4jLogSystem)) {
log("WARN: The current logging system [" + slf4jLogSystem + "] used by SLF4J may not be configured, " +
"because it is not in the configuration list: " + logSystemToBeConfigured + ".");
}
// 如果系统中不存在默认的logSystems，则报错
if (containsNull) {
log("WARN: No log system bound with SLF4J");
}
// 取得log configurators
LogConfigurator[] configurators = new LogConfigurator[logSystemToBeConfigured.size()];
int i = 0;
for (String logSystem : logSystemToBeConfigured) {
String providerClassName = providers.get(logSystem);
if (providerClassName == null) {
throw new IllegalArgumentException("Could not find LogConfigurator for \"" + logSystem
+ "\" by searching in " + PROVIDERS_PATTERN);
}
Class<?> providerClass;
try {
providerClass = cl.loadClass(providerClassName);
} catch (ClassNotFoundException e) {
throw new IllegalArgumentException("Could not find LogConfigurator for " + logSystem, e);
}
if (!LogConfigurator.class.isAssignableFrom(providerClass)) {
throw new IllegalArgumentException(logSystem + " class " + providerClassName
+ " is not a sub-class of " + LogConfigurator.class.getName());
}
LogConfigurator configurator;
try {
configurator = (LogConfigurator) providerClass.newInstance();
} catch (Throwable e) {
throw new IllegalArgumentException("Could not create instance of class " + providerClassName + " for "
+ logSystem, e);
}
configurator.logSystem = logSystem;
configurators[i++] = configurator;
}
return configurators;
}
private static Map<String, String> getProviders(String location, ClassLoader cl) {
Properties props = new Properties();
Enumeration<?> i = null;
try {
i = cl.getResources(location);
} catch (IOException e) {
log("ERROR: Failed to read " + location, e);
}
while (i != null && i.hasMoreElements()) {
URL url = (URL) i.nextElement();
InputStream is = null;
try {
is = url.openStream();
props.load(is);
} catch (Exception e) {
log("ERROR: Failed to read " + url, e);
} finally {
if (is != null) {
try {
is.close();
} catch (IOException e) {
}
}
}
}
Map<String, String> propsMap = new HashMap<String, String>();
for (Map.Entry<?, ?> entry : props.entrySet()) {
String key = trimToNull(entry.getKey());
String className = trimToNull(entry.getValue());
if (key != null && className != null) {
propsMap.put(key.toLowerCase(), className);
}
}
return propsMap;
}
private static String guessSlf4jLogSystem(Map<String, String> providers) {
String s;
try {
s = LoggerFactory.getILoggerFactory().getClass().getName().toLowerCase();
} catch (Throwable e) {
s = null;
}
if (s != null) {
for (String name : providers.keySet()) {
if (s.contains(name)) {
return name;
}
}
}
return null;
}
protected static String trimToNull(Object str) {
if (!(str instanceof String)) {
return null;
}
String result = ((String) str).trim();
if (result == null || result.length() == 0) {
return null;
}
return result;
}
protected static void log(String msg) {
log(msg, null);
}
protected static void log(String msg, Throwable e) {
System.out.flush(); // 防止控制台输出乱序
System.err.println(msg);
if (e != null) {
e.printStackTrace();
}
System.err.flush();
}
}