freemarker报错之八

1、错误描述

freemarker.core.ParseException: Encountered "string" at line 21, column 21 in type.ftl.
Was expecting one of:
    "}" ...
    "." ...
    "[" ...
    "(" ...
    "?" ...
    "!" ...
    <TERMINATING_EXCLAM> ...
    "??" ...
    "+" ...
    "-" ...
    "*" ...
    "/" ...
    "%" ...
    "!=" ...
    "=" ...
    "==" ...
    ">=" ...
    <ESCAPED_GTE> ...
    ">" ...
    <ESCAPED_GT> ...
    <LESS_THAN_EQUALS> ...
    <LESS_THAN> ...
    ".." ...
    <AND> ...
    <OR> ...
    
	at freemarker.core.FMParser.generateParseException(FMParser.java:4702)
	at freemarker.core.FMParser.jj_consume_token(FMParser.java:4573)
	at freemarker.core.FMParser.StringOutput(FMParser.java:1070)
	at freemarker.core.FMParser.Content(FMParser.java:2580)
	at freemarker.core.FMParser.OptionalBlock(FMParser.java:2791)
	at freemarker.core.FMParser.Root(FMParser.java:2963)
	at freemarker.template.Template.<init>(Template.java:171)
	at freemarker.cache.TemplateCache.loadTemplate(TemplateCache.java:447)
	at freemarker.cache.TemplateCache.getTemplate(TemplateCache.java:360)
	at freemarker.cache.TemplateCache.getTemplate(TemplateCache.java:235)
	at freemarker.template.Configuration.getTemplate(Configuration.java:578)
	at freemarker.template.Configuration.getTemplate(Configuration.java:543)
	at com.you.freemarker.FreemarkerTemplate.getTemplate(FreemarkerTemplate.java:52)
	at com.you.freemarker.FreemarkerTemplate.printFtl(FreemarkerTemplate.java:76)
	at com.you.test.freemarker.FreemarkerTest.studentPrint(FreemarkerTest.java:172)
	at com.you.test.freemarker.FreemarkerTest.testDataType(FreemarkerTest.java:159)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	at java.lang.reflect.Method.invoke(Unknown Source)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:45)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:42)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
	at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:28)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:263)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:68)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:47)
	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:231)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:60)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:229)
	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:50)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:222)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:300)
	at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
	at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)

2、错误原因

 ${(num.color)??string}

    “？？”出现错误，不符合freemarker中的语法规定

3、解决办法

     将“？？”修改成符合freemarker语法的“？？？”

${(num.color)???string}

结果：false