freemarker自定义标签报错（五）

freemarker自定义标签

1、错误描述

六月 05, 2014 11:40:49 下午 freemarker.log.JDK14LoggerFactory$JDK14Logger error
严重: Template processing error: "Expression name is undefined on line 18, column 20 in myself.ftl."

Expression name is undefined on line 18, column 20 in myself.ftl.
The problematic instruction:
----------
==> macro write [on line 11, column 10 in myself.ftl]
 in user-directive write [on line 18, column 10 in myself.ftl]
----------

Java backtrace for programmers:
----------
freemarker.core.InvalidReferenceException: Expression name is undefined on line 18, column 20 in myself.ftl.
	at freemarker.core.TemplateObject.assertNonNull(TemplateObject.java:125)
	at freemarker.core.ComparisonExpression.isTrue(ComparisonExpression.java:121)
	at freemarker.core.BooleanExpression._getAsTemplateModel(BooleanExpression.java:61)
	at freemarker.core.Expression.getAsTemplateModel(Expression.java:89)
	at freemarker.core.Environment.visit(Environment.java:591)
	at freemarker.core.UnifiedCall.accept(UnifiedCall.java:106)
	at freemarker.core.Environment.visit(Environment.java:221)
	at freemarker.core.MixedContent.accept(MixedContent.java:92)
	at freemarker.core.Environment.visit(Environment.java:221)
	at freemarker.core.Environment.process(Environment.java:199)
	at freemarker.template.Template.process(Template.java:259)
	at com.you.freemarker.FreemarkerTemplate.printFtl(FreemarkerTemplate.java:77)
	at com.you.test.freemarker.FreemarkerTest.studentPrint(FreemarkerTest.java:217)
	at com.you.test.freemarker.FreemarkerTest.testMyself(FreemarkerTest.java:204)
	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)

Expression name is undefined on line 18, column 20 in myself.ftl.
The problematic instruction:
----------
==> macro write [on line 11, column 10 in myself.ftl]
 in user-directive write [on line 18, column 10 in myself.ftl]
----------

Java backtrace for programmers:
----------
freemarker.core.InvalidReferenceException: Expression name is undefined on line 18, column 20 in myself.ftl.
	at freemarker.core.TemplateObject.assertNonNull(TemplateObject.java:125)
	at freemarker.core.ComparisonExpression.isTrue(ComparisonExpression.java:121)
	at freemarker.core.BooleanExpression._getAsTemplateModel(BooleanExpression.java:61)
	at freemarker.core.Expression.getAsTemplateModel(Expression.java:89)
	at freemarker.core.Environment.visit(Environment.java:591)
	at freemarker.core.UnifiedCall.accept(UnifiedCall.java:106)
	at freemarker.core.Environment.visit(Environment.java:221)
	at freemarker.core.MixedContent.accept(MixedContent.java:92)
	at freemarker.core.Environment.visit(Environment.java:221)
	at freemarker.core.Environment.process(Environment.java:199)
	at freemarker.template.Template.process(Template.java:259)
	at com.you.freemarker.FreemarkerTemplate.printFtl(FreemarkerTemplate.java:77)
	at com.you.test.freemarker.FreemarkerTest.studentPrint(FreemarkerTest.java:217)
	at com.you.test.freemarker.FreemarkerTest.testMyself(FreemarkerTest.java:204)
	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)
<html>
  <head>
    <meta http-equiv="content-type" content="text/html; charset=UTF-8">
    <title>freemarker自定义标签</title>

  </head>

  <body>

Expression name is undefined on line 18, column 20 in myself.ftl.
The problematic instruction:
----------
==> macro write [on line 11, column 10 in myself.ftl]
 in user-directive write [on line 18, column 10 in myself.ftl]
----------

Java backtrace for programmers:
----------
freemarker.core.InvalidReferenceException: Expression name is undefined on line 18, column 20 in myself.ftl.
	at freemarker.core.TemplateObject.assertNonNull(TemplateObject.java:125)
	at freemarker.core.ComparisonExpression.isTrue(ComparisonExpression.java:121)
	at freemarker.core.BooleanExpression._getAsTemplateModel(BooleanExpression.java:61)
	at freemarker.core.Expression.getAsTemplateModel(Expression.java:89)
	at freemarker.core.Environment.visit(Environment.java:591)
	at freemarker.core.UnifiedCall.accept(UnifiedCall.java:106)
	at freemarker.core.Environment.visit(Environment.java:221)
	at freemarker.core.MixedContent.accept(MixedContent.java:92)
	at freemarker.core.Environment.visit(Environment.java:221)
	at freemarker.core.Environment.process(Environment.java:199)
	at freemarker.template.Template.process(Template.java:259)
	at com.you.freemarker.FreemarkerTemplate.printFtl(FreemarkerTemplate.java:77)
	at com.you.test.freemarker.FreemarkerTest.studentPrint(FreemarkerTest.java:217)
	at com.you.test.freemarker.FreemarkerTest.testMyself(FreemarkerTest.java:204)
	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

<#--freemarker自定义标签-->
     <#--对于write自定义标签有两个参数，nums是次数，name是名称-->
	 <#macro write nums name>
	     <#list 1..nums as num>
	                   姓名：张三丰
	                   性别：男
	     </#list>
	 </#macro>

	 <@write 4 name="你好！"/>

有两个参数名，省略了一个，导致出现name没有定义

3、解决办法

（1）添加上参数名

<@write nums=4 name="你好！"/>

（2）删除另一个参数名

<@write 4 "你好！"/>

虽然都可以生成结果，但是不提倡第二种方法