在比较 XML 中的 Logback 和 Janino 字符串时缺少单引号

Question

使用Logback的条件处理比较一个Logback XML配置文件中的两个Strings如下...

<if condition="'test'.equals('test')">
    <then>
        <include resource="logback.local.xml"/>
    </then>
</if>

...导致以下异常。

14:22:08,315 |-ERROR in ch.qos.logback.core.joran.conditional.IfAction - Failed to parse condition ['test'.equals('test')] org.codehaus.commons.compiler.CompileException: Line 1, Column 38: Closing single quote missing
    at org.codehaus.commons.compiler.CompileException: Line 1, Column 38: Closing single quote missing
    at  at org.codehaus.janino.Scanner.scan(Scanner.java:359)
    at  at org.codehaus.janino.Scanner.produce(Scanner.java:267)
    at  at org.codehaus.janino.TokenStreamImpl.produceToken(TokenStreamImpl.java:62)
    at  at org.codehaus.janino.TokenStreamImpl.peek(TokenStreamImpl.java:104)
    at  at org.codehaus.janino.TokenStreamImpl.peek(TokenStreamImpl.java:134)
    at  at org.codehaus.janino.Parser.peek(Parser.java:3145)
    at  at org.codehaus.janino.Parser.parseReturnStatement(Parser.java:2048)
    at  at org.codehaus.janino.Parser.parseStatement(Parser.java:1659)
    at  at org.codehaus.janino.Parser.parseBlockStatement(Parser.java:1512)
    at  at org.codehaus.janino.Parser.parseBlockStatements(Parser.java:1474)
    at  at org.codehaus.janino.Parser.parseMethodDeclarationRest(Parser.java:1313)
    at  at org.codehaus.janino.Parser.parseClassBodyDeclaration(Parser.java:894)
    at  at org.codehaus.janino.ClassBodyEvaluator.cook(ClassBodyEvaluator.java:231)
    at  at org.codehaus.janino.SimpleCompiler.cook(SimpleCompiler.java:200)
    at  at org.codehaus.commons.compiler.Cookable.cook(Cookable.java:76)
    at  at org.codehaus.commons.compiler.Cookable.cook(Cookable.java:71)
    at  at ch.qos.logback.core.joran.conditional.PropertyEvalScriptBuilder.build(PropertyEvalScriptBuilder.java:47)
    at  at ch.qos.logback.core.joran.conditional.IfAction.begin(IfAction.java:65)
    at  at ch.qos.logback.core.joran.spi.Interpreter.callBeginAction(Interpreter.java:269)
    at  at ch.qos.logback.core.joran.spi.Interpreter.startElement(Interpreter.java:145)
    at  at ch.qos.logback.core.joran.spi.Interpreter.startElement(Interpreter.java:128)
    at  at ch.qos.logback.core.joran.spi.EventPlayer.play(EventPlayer.java:50)
    at  at ch.qos.logback.core.joran.GenericConfigurator.doConfigure(GenericConfigurator.java:155)
    at  at ch.qos.logback.core.joran.GenericConfigurator.doConfigure(GenericConfigurator.java:142)
    at  at ch.qos.logback.core.joran.GenericConfigurator.doConfigure(GenericConfigurator.java:103)
    at  at ch.qos.logback.core.joran.GenericConfigurator.doConfigure(GenericConfigurator.java:53)
    at  at ch.qos.logback.classic.util.ContextInitializer.configureByResource(ContextInitializer.java:75)
    at  at ch.qos.logback.classic.util.ContextInitializer.autoConfig(ContextInitializer.java:150)
    at  at org.slf4j.impl.StaticLoggerBinder.init(StaticLoggerBinder.java:84)
    at  at org.slf4j.impl.StaticLoggerBinder.<clinit>(StaticLoggerBinder.java:55)
    at  at org.slf4j.LoggerFactory.bind(LoggerFactory.java:150)
    at  at org.slf4j.LoggerFactory.performInitialization(LoggerFactory.java:124)
    at  at org.slf4j.LoggerFactory.getILoggerFactory(LoggerFactory.java:412)
    at  at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:357)
    at  at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:383)
    at  at com.labcorp.ncp.provider.abn.service.impl.AbnServiceImpl.<clinit>(AbnServiceImpl.java:34)
    at  at sun.reflect.GeneratedSerializationConstructorAccessor5.newInstance(Unknown Source)
    at  at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
    at  at org.objenesis.instantiator.sun.SunReflectionFactoryInstantiator.newInstance(SunReflectionFactoryInstantiator.java:40)
    at  at org.objenesis.ObjenesisBase.newInstance(ObjenesisBase.java:59)
    at  at org.mockito.internal.creation.jmock.ClassImposterizer.createProxy(ClassImposterizer.java:128)
    at  at org.mockito.internal.creation.jmock.ClassImposterizer.imposterise(ClassImposterizer.java:63)
    at  at org.mockito.internal.creation.jmock.ClassImposterizer.imposterise(ClassImposterizer.java:56)
    at  at org.mockito.internal.creation.CglibMockMaker.createMock(CglibMockMaker.java:23)
    at  at org.mockito.internal.util.MockUtil.createMock(MockUtil.java:26)
    at  at org.mockito.internal.MockitoCore.mock(MockitoCore.java:51)
    at  at org.mockito.Mockito.mock(Mockito.java:1243)
    at  at org.mockito.Mockito.mock(Mockito.java:1120)
    at  at com.labcorp.ncp.provider.abn.service.AbnServiceTest.invalidDxCode(AbnServiceTest.java:61)
    at  at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at  at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at  at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at  at java.lang.reflect.Method.invoke(Method.java:606)
    at  at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
    at  at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at  at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
    at  at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
    at  at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
    at  at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
    at  at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
    at  at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
    at  at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
    at  at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
    at  at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
    at  at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
    at  at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
    at  at org.apache.maven.surefire.junit4.JUnit4Provider.execute(JUnit4Provider.java:367)
    at  at org.apache.maven.surefire.junit4.JUnit4Provider.executeWithRerun(JUnit4Provider.java:274)
    at  at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:238)
    at  at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:161)
    at  at org.apache.maven.surefire.booter.ForkedBooter.invokeProviderInSameClassLoader(ForkedBooter.java:290)
    at  at org.apache.maven.surefire.booter.ForkedBooter.runSuitesInProcess(ForkedBooter.java:242)
    at  at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:121)
14:22:08,316 |-ERROR in ch.qos.logback.core.joran.conditional.IfAction - Failed to determine "if then else" result
14:22:08,316 |-INFO in ch.qos.logback.core.joran.action.AppenderAction - About to instantiate appender of type [ch.qos.logback.core.ConsoleAppender]
14:22:08,318 |-INFO in ch.qos.logback.core.joran.action.AppenderAction - Naming appender as [STDOUT]
14:22:08,324 |-INFO in ch.qos.logback.core.joran.action.NestedComplexPropertyIA - Assuming default type [ch.qos.logback.classic.encoder.PatternLayoutEncoder] for [encoder] property
14:22:08,365 |-INFO in ch.qos.logback.core.joran.action.AppenderAction - About to instantiate appender of type [ch.qos.logback.core.rolling.RollingFileAppender]

Answer 1

最终，您定义的条件由 Janino 作为 Groovy 脚本执行。像这样的：

  String script = "public boolean evaluate() { return \"test\".equals(\"test\"); }";

  ClassBodyEvaluator classBodyEvaluator = new ClassBodyEvaluator();
  classBodyEvaluator.setImplementedInterfaces(new Class[] { Condition.class });
  classBodyEvaluator.setExtendedClass(PropertyWrapperForScripts.class);
  classBodyEvaluator.setParentClassLoader(ClassBodyEvaluator.class.getClassLoader());

  StringReader sr = new StringReader(script);
  classBodyEvaluator.cook(null, sr);
  Class clazz = classBodyEvaluator.getClazz();
  Condition instance = (Condition) clazz.newInstance();

因此，您只需要确保条件的值（被替换到脚本中）具有引用的字符串，即"..."。但由于您在 XML 中定义条件，因此必须转义引号，如下所示：

<if condition="&quot;test&quot;.equals(&quot;test&quot;)">

这将产生一个脚本：

public boolean evaluate() { return "test".equals("test"); }

...由ch.qos.logback.core.joran.conditional.PropertyEvalScriptBuilder执行。

我已经验证如下...

<if condition="&quot;test&quot;.equals(&quot;test&quot;)">
    <then>
        <property name="conditionalValue" value="Conditional value is true"/>
    </then>
    <else>
        <property name="conditionalValue" value="Conditional value is false"/>
    </else>
</if>

<appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
    <encoder>
        <pattern>
            %d|%-5p|%t|${conditionalValue}%n
        </pattern>
    </encoder>
</appender>

... 这个 appender 写的日志事件看起来像：

2017-08-09 09:07:02,699|INFO |main|Conditional value is true