freemarker写select组件报错总结（一）

1、具体错误如下

六月 25, 2014 11:26:29 下午 freemarker.log.JDK14LoggerFactory$JDK14Logger error
严重: Template processing error: "Expression name is undefined on line 2, column 33 in inc/select.ftl."

Expression name is undefined on line 2, column 33 in inc/select.ftl.
The problematic instruction:
----------
==> ${name} [on line 2, column 31 in inc/select.ftl]
 in user-directive items.select [on line 10, column 6 in address.ftl]
----------

Java backtrace for programmers:
----------
freemarker.core.InvalidReferenceException: Expression name is undefined on line 2, column 33 in inc/select.ftl.
	at freemarker.core.TemplateObject.assertNonNull(TemplateObject.java:125)
	at freemarker.core.Expression.getStringValue(Expression.java:118)
	at freemarker.core.Expression.getStringValue(Expression.java:93)
	at freemarker.core.DollarVariable.accept(DollarVariable.java:76)
	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.Macro$Context.runMacro(Macro.java:172)
	at freemarker.core.Environment.visit(Environment.java:614)
	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.printFile(FreemarkerTemplate.java:109)
	at com.you.test.freemarker.FreemarkerTest.studentFile(FreemarkerTest.java:260)
	at com.you.test.freemarker.FreemarkerTest.testSelect(FreemarkerTest.java:233)
	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 2, column 33 in inc/select.ftl.
The problematic instruction:
----------
==> ${name} [on line 2, column 31 in inc/select.ftl]
 in user-directive items.select [on line 10, column 6 in address.ftl]
----------

Java backtrace for programmers:
----------
freemarker.core.InvalidReferenceException: Expression name is undefined on line 2, column 33 in inc/select.ftl.
	at freemarker.core.TemplateObject.assertNonNull(TemplateObject.java:125)
	at freemarker.core.Expression.getStringValue(Expression.java:118)
	at freemarker.core.Expression.getStringValue(Expression.java:93)
	at freemarker.core.DollarVariable.accept(DollarVariable.java:76)
	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.Macro$Context.runMacro(Macro.java:172)
	at freemarker.core.Environment.visit(Environment.java:614)
	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.printFile(FreemarkerTemplate.java:109)
	at com.you.test.freemarker.FreemarkerTest.studentFile(FreemarkerTest.java:260)
	at com.you.test.freemarker.FreemarkerTest.testSelect(FreemarkerTest.java:233)
	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

在定义select组件时，给了一个name属性，但是在引用时未给name赋值，导致出错

 <#import "/inc/select.ftl" as items/>
     <@items.select id="city"/>

<#macro select id>
     <select id="${id}" name="${name}">
          <option>---请选择---</option>
     </select>
</#macro>

3、解决办法

将上一段代码修改成：

<#macro select id>
     <select id="${id}" name="${id}">
          <option>---请选择---</option>
     </select>
</#macro>