本文共 12379 字，大约阅读时间需要 41 分钟。

项目中吧所有的配置文件都移植到配置中心了，这样后面发布版本不需要想着改配置文件，直接发包即可了，但是logback.xml 中间的日志路径，logstash host  ，以及日志级别线上和开发环境肯定不同，为了一劳永逸，故想办法将logback的相关参数移动到配置中心去。

1   使用springProperty 来代替Property  定义变量

 如果是仅仅配置上面这个还是不行，因为加载logback.xml代码会比 Apollo的 去配置中心读取配置参数的代码 早执行，会报找不到 

logback.file.dir ，于是第二部需要将 logback.xml换个其他的名字，我叫logback_fhs.xml，这样spring 没办法默认加载此文件。

然后在配置中心定义一个key 

logging.config==classpath:logback_fhs.xml

这样spring会乖乖的等Apollo 把配置参数加载完成之后执行加载logback.xml的代码。

如果你以为到了这里就大吉大利晚上吃鸡你就错了，springBoot如果默认读取不到 logback.xml 会使用默认的参数去初始化logger，当你让spring去加载logback_fhs.xml的时候，spring只判断logback_fhs.xml 是否存在，其实是不会加载的，因为logger已经存在了。

2  使用自定义LogBackConfigListener去初始化logger。

    为了看文章舒服，我吧代码贴到了最后面，代码是在加载logback_fhs.xml 的时候执行了一些clear方法，把默认的一些配置干掉，然后自己在初始化一个logger配置进去。到了这里，正常启动和记录日志没有问题了。

//// Source code recreated from a .class file by IntelliJ IDEA// (powered by Fernflower decompiler)//package  org.springframework.boot.logging;import java.util.Iterator;import java.util.List;import java.util.Locale;import java.util.Map;import java.util.Map.Entry;import java.util.concurrent.atomic.AtomicBoolean;import org.apache.commons.logging.Log;import org.apache.commons.logging.LogFactory;import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;import org.springframework.boot.SpringApplication;import org.springframework.boot.bind.RelaxedPropertyResolver;import org.springframework.boot.context.event.ApplicationEnvironmentPreparedEvent;import org.springframework.boot.context.event.ApplicationFailedEvent;import org.springframework.boot.context.event.ApplicationPreparedEvent;import org.springframework.boot.context.event.ApplicationStartingEvent;import org.springframework.boot.logging.LogLevel;import org.springframework.boot.logging.LoggingSystem;import org.springframework.context.ApplicationContext;import org.springframework.context.ApplicationEvent;import org.springframework.context.event.ContextClosedEvent;import org.springframework.context.event.GenericApplicationListener;import org.springframework.core.ResolvableType;import org.springframework.core.env.ConfigurableEnvironment;import org.springframework.core.env.Environment;import org.springframework.util.LinkedMultiValueMap;import org.springframework.util.MultiValueMap;import org.springframework.util.ResourceUtils;import org.springframework.util.StringUtils;/** * by jackwang * 解决logback 从配置中心读取不起做用的问题 */public class LogBackConfigListener implements GenericApplicationListener {    public static final int DEFAULT_ORDER = -2147483628;    public static final String CONFIG_PROPERTY = "logging.config";    public static final String REGISTER_SHUTDOWN_HOOK_PROPERTY = "logging.register-shutdown-hook";    /** @deprecated */    @Deprecated    public static final String PATH_PROPERTY = "logging.path";    /** @deprecated */    @Deprecated    public static final String FILE_PROPERTY = "logging.file";    public static final String PID_KEY = "PID";    public static final String EXCEPTION_CONVERSION_WORD = "LOG_EXCEPTION_CONVERSION_WORD";    public static final String LOG_FILE = "LOG_FILE";    public static final String LOG_PATH = "LOG_PATH";    public static final String CONSOLE_LOG_PATTERN = "CONSOLE_LOG_PATTERN";    public static final String FILE_LOG_PATTERN = "FILE_LOG_PATTERN";    public static final String LOG_LEVEL_PATTERN = "LOG_LEVEL_PATTERN";    public static final String LOGGING_SYSTEM_BEAN_NAME = "springBootLoggingSystem";    private static MultiValueMap
   
     LOG_LEVEL_LOGGERS = new LinkedMultiValueMap();    private static AtomicBoolean shutdownHookRegistered = new AtomicBoolean(false);    private static Class
    [] EVENT_TYPES;    private static Class
    [] SOURCE_TYPES;    private final Log logger = LogFactory.getLog(this.getClass());    private LoggingSystem loggingSystem;    private int order = -2147483628;    private boolean parseArgs = true;    private LogLevel springBootLogging = null;    public LogBackConfigListener() {    }    public boolean supportsEventType(ResolvableType resolvableType) {        return this.isAssignableFrom(resolvableType.getRawClass(), EVENT_TYPES);    }    public boolean supportsSourceType(Class
     sourceType) {        return this.isAssignableFrom(sourceType, SOURCE_TYPES);    }    private boolean isAssignableFrom(Class
     type, Class... supportedTypes) {        if (type != null) {            Class[] var3 = supportedTypes;            int var4 = supportedTypes.length;            for(int var5 = 0; var5 < var4; ++var5) {                Class
     supportedType = var3[var5];                if (supportedType.isAssignableFrom(type)) {                    return true;                }            }        }        return false;    }    public void onApplicationEvent(ApplicationEvent event) {        if (event instanceof ApplicationEnvironmentPreparedEvent) {            this.onApplicationEnvironmentPreparedEvent((ApplicationEnvironmentPreparedEvent)event);        }    }    private void onApplicationStartingEvent(ApplicationStartingEvent event) {        this.loggingSystem = LoggingSystem.get(event.getSpringApplication().getClassLoader());        this.loggingSystem.beforeInitialize();    }    private void onApplicationEnvironmentPreparedEvent(ApplicationEnvironmentPreparedEvent event) {        if (this.loggingSystem == null) {            this.loggingSystem = LoggingSystem.get(event.getSpringApplication().getClassLoader());        }        this.initialize(event.getEnvironment(), event.getSpringApplication().getClassLoader());    }    private void onApplicationPreparedEvent(ApplicationPreparedEvent event) {        ConfigurableListableBeanFactory beanFactory = event.getApplicationContext().getBeanFactory();        if (!beanFactory.containsBean("springBootLoggingSystem")) {            beanFactory.registerSingleton("springBootLoggingSystem", this.loggingSystem);        }    }    private void onContextClosedEvent() {        if (this.loggingSystem != null) {            this.loggingSystem.cleanUp();        }    }    private void onApplicationFailedEvent() {        if (this.loggingSystem != null) {            this.loggingSystem.cleanUp();        }    }    protected void initialize(ConfigurableEnvironment environment, ClassLoader classLoader) {        (new LoggingSystemProperties(environment)).apply();        LogFile logFile = LogFile.get(environment);        if (logFile != null) {            logFile.applyToSystemProperties();        }        this.initializeEarlyLoggingLevel(environment);        this.initializeSystem(environment, this.loggingSystem, logFile);        this.initializeFinalLoggingLevels(environment, this.loggingSystem);        this.registerShutdownHookIfNecessary(environment, this.loggingSystem);    }    private void initializeEarlyLoggingLevel(ConfigurableEnvironment environment) {        if (this.parseArgs && this.springBootLogging == null) {            if (this.isSet(environment, "debug")) {                this.springBootLogging = LogLevel.DEBUG;            }            if (this.isSet(environment, "trace")) {                this.springBootLogging = LogLevel.TRACE;            }        }    }    private boolean isSet(ConfigurableEnvironment environment, String property) {        String value = environment.getProperty(property);        return value != null && !value.equals("false");    }    private void initializeSystem(ConfigurableEnvironment environment, LoggingSystem system, LogFile logFile) {        LoggingInitializationContext initializationContext = new LoggingInitializationContext(environment);        String logConfig = environment.getProperty("logging.config");        if (this.ignoreLogConfig(logConfig)) {            system.initialize(initializationContext, (String)null, logFile);        } else {            try {                system.cleanUp();                ResourceUtils.getURL(logConfig).openStream().close();                system.initialize(initializationContext, logConfig, logFile);            } catch (Exception var7) {                System.err.println("Logging system failed to initialize using configuration from '" + logConfig + "'");                var7.printStackTrace(System.err);                throw new IllegalStateException(var7);            }        }    }    private boolean ignoreLogConfig(String logConfig) {        return !StringUtils.hasLength(logConfig) || logConfig.startsWith("-D");    }    private void initializeFinalLoggingLevels(ConfigurableEnvironment environment, LoggingSystem system) {        if (this.springBootLogging != null) {            this.initializeLogLevel(system, this.springBootLogging);        }        this.setLogLevels(system, environment);    }    protected void initializeLogLevel(LoggingSystem system, LogLevel level) {        List
    
      loggers = (List)LOG_LEVEL_LOGGERS.get(level);        if (loggers != null) {            Iterator var4 = loggers.iterator();            while(var4.hasNext()) {                String logger = (String)var4.next();                system.setLogLevel(logger, level);            }        }    }    protected void setLogLevels(LoggingSystem system, Environment environment) {        Map
     
       levels = (new RelaxedPropertyResolver(environment)).getSubProperties("logging.level.");        boolean rootProcessed = false;        Iterator var5 = levels.entrySet().iterator();        while(true) {            Entry entry;            String name;            while(true) {                if (!var5.hasNext()) {                    return;                }                entry = (Entry)var5.next();                name = (String)entry.getKey();                if (!name.equalsIgnoreCase("ROOT")) {                    break;                }                if (!rootProcessed) {                    name = null;                    rootProcessed = true;                    break;                }            }            this.setLogLevel(system, environment, name, entry.getValue().toString());        }    }    private void setLogLevel(LoggingSystem system, Environment environment, String name, String level) {        try {            level = environment.resolvePlaceholders(level);            system.setLogLevel(name, this.coerceLogLevel(level));        } catch (RuntimeException var6) {            this.logger.error("Cannot set level: " + level + " for '" + name + "'");        }    }    private LogLevel coerceLogLevel(String level) {        return "false".equalsIgnoreCase(level) ? LogLevel.OFF : LogLevel.valueOf(level.toUpperCase(Locale.ENGLISH));    }    private void registerShutdownHookIfNecessary(Environment environment, LoggingSystem loggingSystem) {        boolean registerShutdownHook = ((Boolean)(new RelaxedPropertyResolver(environment)).getProperty("logging.register-shutdown-hook", Boolean.class, false)).booleanValue();        if (registerShutdownHook) {            Runnable shutdownHandler = loggingSystem.getShutdownHandler();            if (shutdownHandler != null && shutdownHookRegistered.compareAndSet(false, true)) {                this.registerShutdownHook(new Thread(shutdownHandler));            }        }    }    void registerShutdownHook(Thread shutdownHook) {        Runtime.getRuntime().addShutdownHook(shutdownHook);    }    public void setOrder(int order) {        this.order = order;    }    public int getOrder() {        return this.order;    }    public void setSpringBootLogging(LogLevel springBootLogging) {        this.springBootLogging = springBootLogging;    }    public void setParseArgs(boolean parseArgs) {        this.parseArgs = parseArgs;    }    static {        LOG_LEVEL_LOGGERS.add(LogLevel.DEBUG, "org.springframework.boot");        LOG_LEVEL_LOGGERS.add(LogLevel.TRACE, "org.springframework");        LOG_LEVEL_LOGGERS.add(LogLevel.TRACE, "org.apache.tomcat");        LOG_LEVEL_LOGGERS.add(LogLevel.TRACE, "org.apache.catalina");        LOG_LEVEL_LOGGERS.add(LogLevel.TRACE, "org.eclipse.jetty");        LOG_LEVEL_LOGGERS.add(LogLevel.TRACE, "org.hibernate.tool.hbm2ddl");        LOG_LEVEL_LOGGERS.add(LogLevel.DEBUG, "org.hibernate.SQL");        EVENT_TYPES = new Class[]{ApplicationStartingEvent.class, ApplicationEnvironmentPreparedEvent.class, ApplicationPreparedEvent.class, ContextClosedEvent.class, ApplicationFailedEvent.class};        SOURCE_TYPES = new Class[]{SpringApplication.class, ApplicationContext.class};    }}
     
    
   

转载地址：http://ugwni.baihongyu.com/