freemarker報錯之十五
阿新 • • 發佈：2019-01-22
1、錯誤描述
六月 04, 2014 11:04:03 下午 freemarker.log.JDK14LoggerFactory$JDK14Logger error 嚴重: Template processing error: "Expression maps.key is undefined on line 15, column 25 in map.ftl." Expression maps.key is undefined on line 15, column 25 in map.ftl. The problematic instruction: ---------- ==> ${maps.key} [on line 15, column 23 in map.ftl] ---------- Java backtrace for programmers: ---------- freemarker.core.InvalidReferenceException: Expression maps.key is undefined on line 15, column 25 in map.ftl. at freemarker.core.TemplateObject.assertNonNull(TemplateObject.java:125) at freemarker.core.Expression.getStringValue(Expression.java:118) at freemarker.core.Expression.getStringValue(Expression.java:93) at freemarker.core.DollarVariable.accept(DollarVariable.java:76) at freemarker.core.Environment.visit(Environment.java:221) at freemarker.core.MixedContent.accept(MixedContent.java:92) at freemarker.core.Environment.visit(Environment.java:221) at freemarker.core.IteratorBlock$Context.runLoop(IteratorBlock.java:167) at freemarker.core.Environment.visit(Environment.java:428) at freemarker.core.IteratorBlock.accept(IteratorBlock.java:102) 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:210) at com.you.test.freemarker.FreemarkerTest.testMap(FreemarkerTest.java:197) 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 maps.key is undefined on line 15, column 25 in map.ftl. The problematic instruction: ---------- ==> ${maps.key} [on line 15, column 23 in map.ftl] ---------- Java backtrace for programmers: ---------- freemarker.core.InvalidReferenceException: Expression maps.key is undefined on line 15, column 25 in map.ftl. at freemarker.core.TemplateObject.assertNonNull(TemplateObject.java:125) at freemarker.core.Expression.getStringValue(Expression.java:118) at freemarker.core.Expression.getStringValue(Expression.java:93) at freemarker.core.DollarVariable.accept(DollarVariable.java:76) at freemarker.core.Environment.visit(Environment.java:221) at freemarker.core.MixedContent.accept(MixedContent.java:92) at freemarker.core.Environment.visit(Environment.java:221) at freemarker.core.IteratorBlock$Context.runLoop(IteratorBlock.java:167) at freemarker.core.Environment.visit(Environment.java:428) at freemarker.core.IteratorBlock.accept(IteratorBlock.java:102) 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:210) at com.you.test.freemarker.FreemarkerTest.testMap(FreemarkerTest.java:197) 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處理雜湊表的內建函式</title> </head> <body> 張三強 1---- Expression maps.key is undefined on line 15, column 25 in map.ftl. The problematic instruction: ---------- ==> ${maps.key} [on line 15, column 23 in map.ftl] ---------- Java backtrace for programmers: ---------- freemarker.core.InvalidReferenceException: Expression maps.key is undefined on line 15, column 25 in map.ftl. at freemarker.core.TemplateObject.assertNonNull(TemplateObject.java:125) at freemarker.core.Expression.getStringValue(Expression.java:118) at freemarker.core.Expression.getStringValue(Expression.java:93) at freemarker.core.DollarVariable.accept(DollarVariable.java:76) at freemarker.core.Environment.visit(Environment.java:221) at freemarker.core.MixedContent.accept(MixedContent.java:92) at freemarker.core.Environment.visit(Environment.java:221) at freemarker.core.IteratorBlock$Context.runLoop(IteratorBlock.java:167) at freemarker.core.Environment.visit(Environment.java:428) at freemarker.core.IteratorBlock.accept(IteratorBlock.java:102) 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:210) at com.you.test.freemarker.FreemarkerTest.testMap(FreemarkerTest.java:197) 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、錯誤原因
<#assign maps={"1":"張三丰","2":"李思思","3":"張三強","4":"王五"}>
${maps["3"]}
<#assign keys=maps?keys>
<#list keys as key>
${key}----${maps.key}
</#list>其中，${maps.key}未定義，獲取hashmap中的描述不能這樣取值
3、解決辦法
<#--freemarker HashMap取值--> <#assign maps={"1":"張三丰","2":"李思思","3":"張三強","4":"王五"}> ${maps["3"]} <#assign keys=maps?keys> <#list keys as key> ${key}----${maps[key]} </#list>
正確取值：${key}----${maps[key]}
執行結果：
<html> <head> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> <title>freemarker處理雜湊表的內建函式</title> </head> <body> 張三強 1----張三丰 2----李思思 3----張三強 4----王五 </body> </html>