jasper出现NullPointException。急

Question

我写了一个a.jasper文件,在IReport中通过JDBC直接连接可以出来数据.但是放到项目中就出现NullPointException。如下：
java.lang.NullPointerException
at net.sf.jasperreports.engine.JRPropertiesMap.readObject(JRPropertiesMap.java:185)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at java.io.ObjectStreamClass.invokeReadObject(ObjectStreamClass.java:946)
at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1809)
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1719)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1305)
at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1908)
at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1832)
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1719)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1305)
at java.io.ObjectInputStream.readArray(ObjectInputStream.java:1634)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1299)
at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1908)
at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1832)
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1719)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1305)
at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1908)
at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1832)
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1719)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1305)
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:348)
at net.sf.jasperreports.engine.util.JRLoader.loadObject(JRLoader.java:88)
at net.sf.jasperreports.engine.util.JRLoader.loadObject(JRLoader.java:64)
at com.newheight.webapp.action.report.ReportAction.generateReport(ReportAction.java:145)
at com.newheight.webapp.action.report.ReportAction.exportHtml(ReportAction.java:118)
at com.newheight.webapp.action.report.ReportAction$$FastClassByCGLIB$$5d99d159.invoke(<generated>)
at net.sf.cglib.proxy.MethodProxy.invoke(MethodProxy.java:149)
at org.springframework.aop.framework.Cglib2AopProxy$CglibMethodInvocation.invokeJoinpoint(Cglib2AopProxy.java:700)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:149)
at org.springframework.aop.aspectj.MethodInvocationProceedingJoinPoint.proceed(MethodInvocationProceedingJoinPoint.java:77)
at com.newheight.aop.BackendAccessLogAspect.securityAccess(BackendAccessLogAspect.java:56)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethodWithGivenArgs(AbstractAspectJAdvice.java:627)
at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethod(AbstractAspectJAdvice.java:616)
at org.springframework.aop.aspectj.AspectJAroundAdvice.invoke(AspectJAroundAdvice.java:64)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:160)
at org.springframework.aop.aspectj.MethodInvocationProceedingJoinPoint.proceed(MethodInvocationProceedingJoinPoint.java:77)
at com.newheight.aop.ActionAccessAspect.securityAccess(ActionAccessAspect.java:70)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethodWithGivenArgs(AbstractAspectJAdvice.java:627)
at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethod(AbstractAspectJAdvice.java:616)
at org.springframework.aop.aspectj.AspectJAroundAdvice.invoke(AspectJAroundAdvice.java:64)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:160)
at org.springframework.aop.aspectj.MethodInvocationProceedingJoinPoint.proceed(MethodInvocationProceedingJoinPoint.java:77)
at com.newheight.aop.ExceptionHandlerAspect.exceptionHandler(ExceptionHandlerAspect.java:52)
at sun.reflect.GeneratedMethodAccessor71.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethodWithGivenArgs(AbstractAspectJAdvice.java:627)
at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethod(AbstractAspectJAdvice.java:616)
at org.springframework.aop.aspectj.AspectJAroundAdvice.invoke(AspectJAroundAdvice.java:64)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:90)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)
at org.springframework.aop.framework.Cglib2AopProxy$DynamicAdvisedInterceptor.intercept(Cglib2AopProxy.java:635)
at com.newheight.webapp.action.report.ReportAction$$EnhancerByCGLIB$$bcfe711c.exportHtml(<generated>)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)

Answer 1

在这行com.newheight.webapp.action.report.ReportAction.generateReport(ReportAction.java:145) 设个断点  看看是那个报null了，这样问题就容易找到

Answer 2

现在出现如下问题:net.sf.jasperreports.engine.fill.JRExpressionEvalException: Error evaluating expression : 
Source text : $F{sold_date}
at net.sf.jasperreports.engine.fill.JREvaluator.evaluate(JREvaluator.java:197)
at net.sf.jasperreports.engine.fill.JRCalculator.evaluate(JRCalculator.java:537)
at net.sf.jasperreports.engine.fill.JRCalculator.evaluate(JRCalculator.java:505)
at net.sf.jasperreports.engine.fill.JRFillElement.evaluateExpression(JRFillElement.java:826)
at net.sf.jasperreports.engine.fill.JRFillTextField.evaluateText(JRFillTextField.java:368)
at net.sf.jasperreports.engine.fill.JRFillTextField.evaluate(JRFillTextField.java:353)
at net.sf.jasperreports.engine.fill.JRFillElementContainer.evaluate(JRFillElementContainer.java:275)
at net.sf.jasperreports.engine.fill.JRFillBand.evaluate(JRFillBand.java:426)
at net.sf.jasperreports.engine.fill.JRVerticalFiller.fillColumnBand(JRVerticalFiller.java:1380)
at net.sf.jasperreports.engine.fill.JRVerticalFiller.fillDetail(JRVerticalFiller.java:692)
at net.sf.jasperreports.engine.fill.JRVerticalFiller.fillReportStart(JRVerticalFiller.java:255)
at net.sf.jasperreports.engine.fill.JRVerticalFiller.fillReport(JRVerticalFiller.java:113)
at net.sf.jasperreports.engine.fill.JRBaseFiller.fill(JRBaseFiller.java:879)
at net.sf.jasperreports.engine.fill.JRBaseFiller.fill(JRBaseFiller.java:801)
at net.sf.jasperreports.engine.fill.JRFiller.fillReport(JRFiller.java:89)
at net.sf.jasperreports.engine.JasperFillManager.fillReport(JasperFillManager.java:601)
at com.newheight.webapp.action.report.ReportAction.generateReport(ReportAction.java:166)
at com.newheight.webapp.action.report.ReportAction.exportHtml(ReportAction.java:118)
at com.newheight.webapp.action.report.ReportAction$$FastClassByCGLIB$$5d99d159.invoke(<generated>)
at net.sf.cglib.proxy.MethodProxy.invoke(MethodProxy.java:149)
at org.springframework.aop.framework.Cglib2AopProxy$CglibMethodInvocation.invokeJoinpoint(Cglib2AopProxy.java:700)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:149)
at org.springframework.aop.aspectj.MethodInvocationProceedingJoinPoint.proceed(MethodInvocationProceedingJoinPoint.java:77)
at com.newheight.aop.BackendAccessLogAspect.securityAccess(BackendAccessLogAspect.java:56)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethodWithGivenArgs(AbstractAspectJAdvice.java:627)
at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethod(AbstractAspectJAdvice.java:616)
at org.springframework.aop.aspectj.AspectJAroundAdvice.invoke(AspectJAroundAdvice.java:64)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:160)
at org.springframework.aop.aspectj.MethodInvocationProceedingJoinPoint.proceed(MethodInvocationProceedingJoinPoint.java:77)
at com.newheight.aop.ActionAccessAspect.securityAccess(ActionAccessAspect.java:70)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethodWithGivenArgs(AbstractAspectJAdvice.java:627)
at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethod(AbstractAspectJAdvice.java:616)
at org.springframework.aop.aspectj.AspectJAroundAdvice.invoke(AspectJAroundAdvice.java:64)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:160)
at org.springframework.aop.aspectj.MethodInvocationProceedingJoinPoint.proceed(MethodInvocationProceedingJoinPoint.java:77)
at com.newheight.aop.ExceptionHandlerAspect.exceptionHandler(ExceptionHandlerAspect.java:52)
at sun.reflect.GeneratedMethodAccessor71.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethodWithGivenArgs(AbstractAspectJAdvice.java:627)
at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethod(AbstractAspectJAdvice.java:616)
at org.springframework.aop.aspectj.AspectJAroundAdvice.invoke(AspectJAroundAdvice.java:64)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:90)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)
at org.springframework.aop.framework.Cglib2AopProxy$DynamicAdvisedInterceptor.intercept(Cglib2AopProxy.java:635)
at com.newheight.webapp.action.report.ReportAction$$EnhancerByCGLIB$$7e4dd3f.exportHtml(<generated>)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:404)
at com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:267)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:229)
at com.newheight.webapp.interceptor.BackendLoginInterceptor.intercept(BackendLoginInterceptor.java:24)
at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:224)
at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:223)
at com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:221)
at com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:150)
at org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:48)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:86)
at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:224)
at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:223)
at com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:221)
...
Caused by: java.lang.ClassCastException: java.util.Date
at ProductSaleDetail_1235116557112_125553.evaluate(ProductSaleDetail_1235116557112_125553:216)
at net.sf.jasperreports.engine.fill.JREvaluator.evaluate(JREvaluator.java:186)
... 181 more
net.sf.jasperreports.engine.JRException: No input source supplied to the exporter.
at net.sf.jasperreports.engine.JRAbstractExporter.setInput(JRAbstractExporter.java:605)
at net.sf.jasperreports.engine.export.JRHtmlExporter.exportReport(JRHtmlExporter.java:216)
at com.newheight.webapp.action.report.ReportAction.htmlReport(ReportAction.java:227)
at com.newheight.webapp.action.report.ReportAction.exportHtml(ReportAction.java:119)
at com.newheight.webapp.action.report.ReportAction$$FastClassByCGLIB$$5d99d159.invoke(<generated>)
at net.sf.cglib.proxy.MethodProxy.invoke(MethodProxy.java:149)

Answer 3

java.lang.ClassCastException: java.util.Date 
类型转换不对，该是在你这行代码出了问题吧com.newheight.webapp.action.report.ReportAction.generateReport(ReportAction.java:166) 

Answer 4

我当然知道是类型转换不对,这个JASPER文件是以前一个已经跳槽的同事生成的,他用的版本比较低,具体版本号不知道,我用的是3.0.0版本的.我在这个文件里追加了一个field,根本没有动他原来的东西,这个日期是以前就存在的,编译后直接用JDBC连接是可以出来数据的.放在项目里运行.就出错.java部分的代码我只是在VO里追加了这个field的getter和setter然后修改了SQL语句多检索一个field而已.是不是两个版本的问题。

Answer 5

刚开始出现的空指针错误,是我用以前的JASPER的LIB,然后我把3.0的JAR替换老的JAR之后,就出现转型错误.

Answer 6

日期类型请注意java.sql.Date ....java.util.Date 

Answer 7

谢谢大家！问题找到了：原因是我在写SQL语句时，自动从数据库检索类型，
所以有一个字段为：java.util.Timestamp类型。
我存储结果的ENTITY中该字段的类型为：java.util.Date。
将java.util.Timestamp类型改为：java.util.Date就可以了。

Answer 8

救命啊!
我也遇到jasper出现NullPointException了
在ireport工具中是好的.就是不能在java中用.这个项目以前是别人做的,里边有一些jasper文件可以用.但是换上我现在写jasper文件的就不行啊.
java.lang.NullPointerException
net.sf.jasperreports.engine.JRPropertiesMap.readObject(JRPropertiesMap.java:185)
sun.reflect.GeneratedMethodAccessor68.invoke(Unknown Source)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
java.lang.reflect.Method.invoke(Method.java:585)
java.io.ObjectStreamClass.invokeReadObject(ObjectStreamClass.java:946)
java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1809)
java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1719)
java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1305)
java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1908)
java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1832)
java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1719)
java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1305)
java.io.ObjectInputStream.readArray(ObjectInputStream.java:1634)
java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1299)
java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1908)
java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1832)
java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1719)
java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1305)
java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1908)
java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1832)
java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1719)
java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1305)
java.io.ObjectInputStream.readObject(ObjectInputStream.java:348)
net.sf.jasperreports.engine.util.JRLoader.loadObject(JRLoader.java:88)
net.sf.jasperreports.engine.util.JRLoader.loadObjectFromLocation(JRLoader.java:258)
net.sf.jasperreports.engine.util.JRLoader.loadObjectFromLocation(JRLoader.java:226)
com.bean.analyse.GenerateFile.generatePDF(GenerateFile.java:68)
com.login.servlet.MyCreateServlet.doPost(MyCreateServlet.java:239)
com.login.servlet.MyCreateServlet.doGet(MyCreateServlet.java:20)
javax.servlet.http.HttpServlet.service(HttpServlet.java:689)
com.login.servlet.MyCreateServlet.service(MyCreateServlet.java:291)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)