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