13.7 SpringBoot集成日志系统logback的几个问题

问题1： Logging system failed to initialize using configuration from 'logback.xml '

application.properties配置文件中value后面有空格。

logging.config=logback.xml

让人感到疑惑的是，SpringBoot居然没有对application.properties配置文件value末端作空格trim处理。

问题2：java.lang.IllegalStateException: java.io.FileNotFoundException: class path resource [/logback-lightsword.xml] cannot be resolved to URL because it does not exist

问题描述

配置内容：

#logginglogging.config=classpath:/logback-lightsword.xml

报错日志：

java.lang.IllegalStateException: java.io.FileNotFoundException: class path resource [/logback-lightsword.xml] cannot be resolved to URL because it does not exist    at org.springframework.boot.logging.LoggingApplicationListener.initializeSystem(LoggingApplicationListener.java:311)    at org.springframework.boot.logging.LoggingApplicationListener.initialize(LoggingApplicationListener.java:272)    at org.springframework.boot.logging.LoggingApplicationListener.onApplicationEnvironmentPreparedEvent(LoggingApplicationListener.java:235)    at org.springframework.boot.logging.LoggingApplicationListener.onApplicationEvent(LoggingApplicationListener.java:208)    at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:167)    at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139)    at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:122)    at org.springframework.boot.context.event.EventPublishingRunListener.environmentPrepared(EventPublishingRunListener.java:72)    at org.springframework.boot.SpringApplicationRunListeners.environmentPrepared(SpringApplicationRunListeners.java:54)    at org.springframework.boot.SpringApplication.prepareEnvironment(SpringApplication.java:338)    at org.springframework.boot.SpringApplication.run(SpringApplication.java:309)    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1187)    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1176)    at com.springboot.in.action.LightSwordApplication$.delayedEndpoint$com$springboot$in$action$LightSwordApplication$1(LightSwordApplication.scala:6)    at com.springboot.in.action.LightSwordApplication$delayedInit$body.apply(LightSwordApplication.scala:5)    at scala.Function0.apply$mcV$sp(Function0.scala:34)    at scala.Function0.apply$mcV$sp$(Function0.scala:34)    at scala.runtime.AbstractFunction0.apply$mcV$sp(AbstractFunction0.scala:12)    at scala.App.$anonfun$main$1$adapted(App.scala:76)    at scala.App$$Lambda$5/1451043227.apply(Unknown Source)    at scala.collection.immutable.List.foreach(List.scala:389)    at scala.App.main(App.scala:76)    at scala.App.main$(App.scala:74)    at com.springboot.in.action.LightSwordApplication$.main(LightSwordApplication.scala:5)    at com.springboot.in.action.LightSwordApplication.main(LightSwordApplication.scala)    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)    at java.lang.reflect.Method.invoke(Method.java:497)    at org_scala_tools_maven_executions.MainHelper.runMain(MainHelper.java:161)    at org_scala_tools_maven_executions.MainWithArgsInFile.main(MainWithArgsInFile.java:26)Caused by: java.io.FileNotFoundException: class path resource [/logback-lightsword.xml] cannot be resolved to URL because it does not exist    at org.springframework.util.ResourceUtils.getURL(ResourceUtils.java:135)    at org.springframework.boot.logging.LoggingApplicationListener.initializeSystem(LoggingApplicationListener.java:303)    ... 30 common frames omitted

原因分析

涉及报错的源码在org.springframework.util.ResourceUtils

    /**     * Resolve the given resource location to a {@code java.net.URL}.     * <p>Does not check whether the URL actually exists; simply returns     * the URL that the given location would correspond to.     * @param resourceLocation the resource location to resolve: either a     * "classpath:" pseudo URL, a "file:" URL, or a plain file path     * @return a corresponding URL object     * @throws FileNotFoundException if the resource cannot be resolved to a URL     */    public static URL getURL(String resourceLocation) throws FileNotFoundException {        Assert.notNull(resourceLocation, "Resource location must not be null");        if (resourceLocation.startsWith(CLASSPATH_URL_PREFIX)) {            String path = resourceLocation.substring(CLASSPATH_URL_PREFIX.length());            ClassLoader cl = ClassUtils.getDefaultClassLoader();            URL url = (cl != null ? cl.getResource(path) : ClassLoader.getSystemResource(path));            if (url == null) {                String description = "class path resource [" + path + "]";                throw new FileNotFoundException(description +                        " cannot be resolved to URL because it does not exist");            }            return url;        }        try {            // try URL            return new URL(resourceLocation);        }        catch (MalformedURLException ex) {            // no URL -> treat as file path            try {                return new File(resourceLocation).toURI().toURL();            }            catch (MalformedURLException ex2) {                throw new FileNotFoundException("Resource location [" + resourceLocation +                        "] is neither a URL not a well-formed file path");            }        }    }

通过源码，我们可以看出spring配置文件里这个locations是uri表示，也就是说我们写的logback-dev.xml是当前相对路径。

解决方案

spring配置文件里这个locations是相对路径，要访问classpath，要使用相对路径：

logging.config=classpath:logback-dev.xml

问题3： SpringBoot集成日志logback.groovy报错： Groovy classes are not available on the class path. ABORTING INITIALIZATION.

问题描述

SpringBoot集成日志logback.groovy报错： Groovy classes are not available on the class path. ABORTING INITIALIZATION.

logback.groovy配置文件内容如下：

//https://logback.qos.ch/translator/asGroovy.htmlimport ch.qos.logback.classic.encoder.PatternLayoutEncoderimport ch.qos.logback.classic.filter.ThresholdFilterimport ch.qos.logback.core.ConsoleAppenderimport ch.qos.logback.core.rolling.RollingFileAppenderimport ch.qos.logback.core.rolling.TimeBasedRollingPolicyimport java.nio.charset.Charsetimport static ch.qos.logback.classic.Level.*def USER_HOME = System.getProperty("user.home")def APP_NAME = "lightsword"scan("60 seconds")context.name = "${APP_NAME}"jmxConfigurator()logger("org.springframework.web", INFO)logger("com.springboot.in.action", TRACE)logger("org.apache.velocity.runtime.log", INFO)appender("CONSOLE", ConsoleAppender) {    encoder(PatternLayoutEncoder) {        pattern = "%d{HH:mm:ss.SSS} [%thread] %-5level %logger{35} - %msg %n"        charset = Charset.forName("utf8")    }}appender("dailyRollingFileAppender", RollingFileAppender) {    file = "${USER_HOME}/logs/${APP_NAME}"    rollingPolicy(TimeBasedRollingPolicy) {        fileNamePattern = "${APP_NAME}.%d{yyyy-MM-dd}.log"        maxHistory = 30    }    filter(ThresholdFilter) {        level = ERROR    }    encoder(PatternLayoutEncoder) {        pattern = "%d{HH:mm:ss.SSS} [%thread] %-5level %logger{35} - %msg %n"    }}root(DEBUG, ["CONSOLE", "dailyRollingFileAppender"])

详细日志如下：

ERROR in ch.qos.logback.classic.LoggerContext[default] - Groovy classes are not available on the class path. ABORTING INITIALIZATION.    at org.springframework.boot.logging.LoggingApplicationListener.initializeSystem(LoggingApplicationListener.java:311)    at org.springframework.boot.logging.LoggingApplicationListener.initialize(LoggingApplicationListener.java:272)    at org.springframework.boot.logging.LoggingApplicationListener.onApplicationEnvironmentPreparedEvent(LoggingApplicationListener.java:235)    at org.springframework.boot.logging.LoggingApplicationListener.onApplicationEvent(LoggingApplicationListener.java:208)    at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:167)    at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139)    at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:122)    at org.springframework.boot.context.event.EventPublishingRunListener.environmentPrepared(EventPublishingRunListener.java:72)    at org.springframework.boot.SpringApplicationRunListeners.environmentPrepared(SpringApplicationRunListeners.java:54)    at org.springframework.boot.SpringApplication.prepareEnvironment(SpringApplication.java:338)    at org.springframework.boot.SpringApplication.run(SpringApplication.java:309)    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1187)    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1176)    at com.springboot.in.action.LightSwordApplication$.delayedEndpoint$com$springboot$in$action$LightSwordApplication$1(LightSwordApplication.scala:6)    at com.springboot.in.action.LightSwordApplication$delayedInit$body.apply(LightSwordApplication.scala:5)    at scala.Function0.apply$mcV$sp(Function0.scala:34)    at scala.Function0.apply$mcV$sp$(Function0.scala:34)    at scala.runtime.AbstractFunction0.apply$mcV$sp(AbstractFunction0.scala:12)    at scala.App.$anonfun$main$1$adapted(App.scala:76)    at scala.App$$Lambda$5/1451043227.apply(Unknown Source)    at scala.collection.immutable.List.foreach(List.scala:389)    at scala.App.main(App.scala:76)    at scala.App.main$(App.scala:74)    at com.springboot.in.action.LightSwordApplication$.main(LightSwordApplication.scala:5)    at com.springboot.in.action.LightSwordApplication.main(LightSwordApplication.scala)    ... 6 moreCaused by: java.lang.IllegalStateException: Logback configuration error detected: ERROR in ch.qos.logback.classic.LoggerContext[default] - Groovy classes are not available on the class path. ABORTING INITIALIZATION.    at org.springframework.boot.logging.logback.LogbackLoggingSystem.loadConfiguration(LogbackLoggingSystem.java:161)    at org.springframework.boot.logging.AbstractLoggingSystem.initializeWithSpecificConfig(AbstractLoggingSystem.java:57)    at org.springframework.boot.logging.AbstractLoggingSystem.initialize(AbstractLoggingSystem.java:47)

原因分析

在类路径中没有Groovy类。

解决方案

项目中添加groovy依赖：

 <!-- https://mvnrepository.com/artifact/org.codehaus.groovy/groovy-all -->        <dependency>            <groupId>org.codehaus.groovy</groupId>            <artifactId>groovy-all</artifactId>            <version>${groovy.version}</version>        </dependency>