需求：过滤掉结果集中某字段值为true的
List<ExerciseModel> collect = search.getContent().stream()
.filter(t->t.getIsDisabled()!=true)
.map(t -> ModelUtils.copyProperties(t, new ExerciseModel()))
.collect(Collectors.toList());结果报错：
java.lang.NullPointerException
at com.ruizhi.backend.controller.ExerciseController.lambda$searchEnable$0(ExerciseController.java:97)
at java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:174)
at java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1382)
at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481)
at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471)
at java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:708)
at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
at java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:499)
at com.ruizhi.backend.controller.ExerciseController.searchEnable(ExerciseController.java:99)
at com.ruizhi.backend.controller.ExerciseController$$FastClassBySpringCGLIB$$3e984c40.invoke(<generated>)
at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218)
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:771)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163)
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:749)
at org.springframework.aop.aspectj.MethodInvocationProceedingJoinPoint.proceed(MethodInvocationProceedingJoinPoint.java:88)
at com.jamerly.common.advice.BizReturnAdvice.doBizReturn(BizReturnAdvice.java:25)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethodWithGivenArgs(AbstractAspectJAdvice.java:644)
at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethod(AbstractAspectJAdvice.java:633)
at org.springframework.aop.aspectj.AspectJAroundAdvice.invoke(AspectJAroundAdvice.java:70)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:175)
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:749)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:95)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:749)
at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:691)
at com.ruizhi.backend.controller.ExerciseController$$EnhancerBySpringCGLIB$$c8124351.searchEnable(<generated>)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:190)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:105)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:878)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:792)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:626)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:733)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:143)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:374)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1590)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:748)
2021-03-29 14:54:23.709 ERROR 22416 --- [nio-8081-exec-1] c.jamerly.common.advice.BizReturnAdvice : com.ruizhi.backend.controller.ExerciseController.lambda$searchEnable$0(ExerciseController.java:97)\njava.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:174)\njava.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1382)\njava.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481)\njava.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471)\njava.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:708)\njava.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)\njava.util.stream.ReferencePipeline.collect(ReferencePipeline.java:499)\ncom.ruizhi.backend.controller.ExerciseController.searchEnable(ExerciseController.java:99)\ncom.ruizhi.backend.controller.ExerciseController$$FastClassBySpringCGLIB$$3e984c40.invoke(<generated>)\norg.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218)\norg.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:771)\norg.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163)\norg.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:749)\norg.springframework.aop.aspectj.MethodInvocationProceedingJoinPoint.proceed(MethodInvocationProceedingJoinPoint.java:88)\ncom.jamerly.common.advice.BizReturnAdvice.doBizReturn(BizReturnAdvice.java:25)\nsun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)\nsun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)\nsun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)\njava.lang.reflect.Method.invoke(Method.java:498)\norg.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethodWithGivenArgs(AbstractAspectJAdvice.java:644)\norg.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethod(AbstractAspectJAdvice.java:633)\norg.springframework.aop.aspectj.AspectJAroundAdvice.invoke(AspectJAroundAdvice.java:70)\norg.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:175)\norg.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:749)\norg.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:95)\norg.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)\norg.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:749)\norg.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:691)\ncom.ruizhi.backend.controller.ExerciseController$$EnhancerBySpringCGLIB$$c8124351.searchEnable(<generated>)\nsun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)\nsun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)\nsun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)\njava.lang.reflect.Method.invoke(Method.java:498)\norg.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:190)\norg.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138)\norg.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:105)\norg.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:878)\norg.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:792)\norg.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)\norg.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040)\norg.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943)\norg.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006)\norg.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898)\njavax.servlet.http.HttpServlet.service(HttpServlet.java:626)\norg.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883)\njavax.servlet.http.HttpServlet.service(HttpServlet.java:733)\norg.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)\norg.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)\norg.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)\norg.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)\norg.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)\norg.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100)\norg.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)\norg.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)\norg.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)\norg.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93)\norg.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)\norg.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)\norg.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)\norg.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201)\norg.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)\norg.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)\norg.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)\norg.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202)\norg.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97)\norg.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541)\norg.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:143)\norg.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)\norg.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78)\norg.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)\norg.apache.coyote.http11.Http11Processor.service(Http11Processor.java:374)\norg.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)\norg.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868)\norg.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1590)\norg.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)\njava.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)\njava.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)\norg.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)\njava.lang.Thread.run(Thread.java:748)空指针异常。
解决方式：将t.getIsDisabled()!=true改成t.getIsDisabled()!=Boolean.TRUE
List<ExerciseModel> collect = search.getContent().stream()
.filter(t->t.getIsDisabled()!=Boolean.TRUE)
.map(t -> ModelUtils.copyProperties(t, new ExerciseModel()))
.collect(Collectors.toList());原因：待补充