EL1008E: Property or field 'timestamp' cannot be found on object of type 'java.util.HashMap' - maybe not public-請求springboot-后台報錯

一、問題由來

　　自己在使用node.js寫的前端項目訪問springBoot訪問的后端項目的時候，springboot項目中報這個錯，拋出這個異常。

詳細的錯誤信息如下:

Servlet.service() for servlet [dispatcherServlet] in context with path [/applets] threw exception [Request processing failed; nested exception is org.springframework.expression.spel.SpelEvaluationException: EL1008E: Property or field 'timestamp' cannot be found on object of type 'java.util.HashMap' - maybe not public?] with root cause

org.springframework.expression.spel.SpelEvaluationException: EL1008E: Property or field 'timestamp' cannot be found on object of type 'java.util.HashMap' - maybe not public?
at org.springframework.expression.spel.ast.PropertyOrFieldReference.readProperty(PropertyOrFieldReference.java:226) ~[spring-expression-4.3.14.RELEASE.jar:4.3.14.RELEASE]
at org.springframework.expression.spel.ast.PropertyOrFieldReference.getValueInternal(PropertyOrFieldReference.java:94) ~[spring-expression-4.3.14.RELEASE.jar:4.3.14.RELEASE]
at org.springframework.expression.spel.ast.PropertyOrFieldReference.getValueInternal(PropertyOrFieldReference.java:81) ~[spring-expression-4.3.14.RELEASE.jar:4.3.14.RELEASE]
at org.springframework.expression.spel.ast.SpelNodeImpl.getValue(SpelNodeImpl.java:121) ~[spring-expression-4.3.14.RELEASE.jar:4.3.14.RELEASE]
at org.springframework.expression.spel.standard.SpelExpression.getValue(SpelExpression.java:262) ~[spring-expression-4.3.14.RELEASE.jar:4.3.14.RELEASE]
at org.springframework.boot.autoconfigure.web.ErrorMvcAutoConfiguration$ExpressionResolver.resolvePlaceholder(ErrorMvcAutoConfiguration.java:288) ~[spring-boot-autoconfigure-1.5.10.RELEASE.jar:1.5.10.RELEASE]
at org.springframework.boot.autoconfigure.web.NonRecursivePropertyPlaceholderHelper$NonRecursivePlaceholderResolver.resolvePlaceholder(NonRecursivePropertyPlaceholderHelper.java:56) ~[spring-boot-autoconfigure-1.5.10.RELEASE.jar:1.5.10.RELEASE]
at org.springframework.util.PropertyPlaceholderHelper.parseStringValue(PropertyPlaceholderHelper.java:147) ~[spring-core-4.3.14.RELEASE.jar:4.3.14.RELEASE]
at org.springframework.boot.autoconfigure.web.NonRecursivePropertyPlaceholderHelper.parseStringValue(NonRecursivePropertyPlaceholderHelper.java:38) ~[spring-boot-autoconfigure-1.5.10.RELEASE.jar:1.5.10.RELEASE]
at org.springframework.util.PropertyPlaceholderHelper.replacePlaceholders(PropertyPlaceholderHelper.java:126) ~[spring-core-4.3.14.RELEASE.jar:4.3.14.RELEASE]
at org.springframework.boot.autoconfigure.web.ErrorMvcAutoConfiguration$SpelView.render(ErrorMvcAutoConfiguration.java:226) ~[spring-boot-autoconfigure-1.5.10.RELEASE.jar:1.5.10.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1286) ~[spring-webmvc-4.3.14.RELEASE.jar:4.3.14.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1041) ~[spring-webmvc-4.3.14.RELEASE.jar:4.3.14.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:984) ~[spring-webmvc-4.3.14.RELEASE.jar:4.3.14.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901) ~[spring-webmvc-4.3.14.RELEASE.jar:4.3.14.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970) ~[spring-webmvc-4.3.14.RELEASE.jar:4.3.14.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861) ~[spring-webmvc-4.3.14.RELEASE.jar:4.3.14.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:635) ~[tomcat-embed-core-8.5.27.jar:8.5.27]
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846) ~[spring-webmvc-4.3.14.RELEASE.jar:4.3.14.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:742) ~[tomcat-embed-core-8.5.27.jar:8.5.27]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-8.5.27.jar:8.5.27]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.27.jar:8.5.27]
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) ~[tomcat-embed-websocket-8.5.27.jar:8.5.27]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.27.jar:8.5.27]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.27.jar:8.5.27]
at applets.common.filter.ReplaceStreamFilter.doFilter(ReplaceStreamFilter.java:31) ~[classes/:na]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.27.jar:8.5.27]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.27.jar:8.5.27]
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99) ~[spring-web-4.3.14.RELEASE.jar:4.3.14.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.14.RELEASE.jar:4.3.14.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.27.jar:8.5.27]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.27.jar:8.5.27]
at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:108) ~[spring-web-4.3.14.RELEASE.jar:4.3.14.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.14.RELEASE.jar:4.3.14.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.27.jar:8.5.27]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.27.jar:8.5.27]
at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:81) ~[spring-web-4.3.14.RELEASE.jar:4.3.14.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.14.RELEASE.jar:4.3.14.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.27.jar:8.5.27]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.27.jar:8.5.27]
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197) ~[spring-web-4.3.14.RELEASE.jar:4.3.14.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.14.RELEASE.jar:4.3.14.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.27.jar:8.5.27]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.27.jar:8.5.27]
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:199) ~[tomcat-embed-core-8.5.27.jar:8.5.27]
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-8.5.27.jar:8.5.27]
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:504) [tomcat-embed-core-8.5.27.jar:8.5.27]
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140) [tomcat-embed-core-8.5.27.jar:8.5.27]
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81) [tomcat-embed-core-8.5.27.jar:8.5.27]
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87) [tomcat-embed-core-8.5.27.jar:8.5.27]
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342) [tomcat-embed-core-8.5.27.jar:8.5.27]
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:803) [tomcat-embed-core-8.5.27.jar:8.5.27]
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-embed-core-8.5.27.jar:8.5.27]
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:790) [tomcat-embed-core-8.5.27.jar:8.5.27]
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1459) [tomcat-embed-core-8.5.27.jar:8.5.27]
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-8.5.27.jar:8.5.27]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [na:1.8.0_121]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [na:1.8.0_121]
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-8.5.27.jar:8.5.27]
at java.lang.Thread.run(Thread.java:745) [na:1.8.0_121]

二、問題分析

自己使用postman進行請求時，是沒有問題的，這就讓我感到非常奇怪，怎么會出現這個BUG呢，並且我反復的請求都會出現這個問題。

既然使用postman請求沒有問題，那可能是我使用node項目進行請求時出現的問題。自己的設置的一些請求相關的內容為:

const params = {'loginToken': 'loginToken'};
let url = 'http://127.0.0.1:23458/applets/user/check';
let method = 'get';

needle.request(method, url, params, {
    //設置header
    headers: {'Content-Type':'application/json'}
}, function(error, response) {
    bodyResult = response.body;
});

const needle = require('needle');

Springboot后端項目的代碼如下:

 

 最終的錯誤是在一個過濾器中報出來的。

 

 

三、解決方案

自己一步一步的排查，一步一步的嘗試着來解決這個問題。也去百度里面搜索了一下相關問題的答案，可是和我遇到的問題都不太一樣，

可是提供了一個思路，有可能是全局異常處理器中出現問題。

嘗試一:

我首先將這個過濾器注銷掉進行測試，發現還是報這個錯誤，那就證明不是這個過濾器導致的。

嘗試二：

我在全局異常處理器中打印輸出語句，進行測試發現，輸出語句正常輸出后，才會報這個錯誤。

 對於這個模型視圖和解析器，它在處理的時候，就是一個map結構，我有一種猜想，是不是這里這個模型解析器里面沒有 timestamp 這個key的值，

才導致出現問題呢。帶着這個疑問，我添加了一行代碼 mav.addObjCommonUtil.getTimeMills());，結果沒有報這個錯，卻報另外一個錯。

錯誤信息和上面差不多，說是缺少status這個參數，我繼續添加代碼mav.addObject("status", 200);，又繼續報新的錯誤。最終添加的代碼如下:

mav.addObject("timestamp", CommonUtil.getTimeMills());
mav.addObject("error", "沒有錯誤頁面");
mav.addObject("status", 200);
mav.addObject("message", e.getMessage());

將這四行代碼都添加后，確實沒在標題中的錯誤，卻返回一個新的錯誤信息，錯誤信息如下:
This application has no explicit mapping for /error, so you are seeing this as a fallback
去百度里面查看了一下相關信息，和自己遇到的問題還是不太符合，然后繼續排查。

嘗試三:
仔細排查，終於找到原因，springboot中寫這個方法時，是使用的post方法進行接收，發送的時候我是使用get請求進行發送，
因此出現問題。只想說聲無語，可是也解決了標題中報出異常的問題，在全局錯誤異常中添加那幾行代碼還是有用的，最起碼不在
繼續報錯，這也是之前代碼中存在的問題。吃一塹長一智，另外在全局異常處理的時候，還使用了一個新的注解，讓其不在返回視圖，而是直接
返回JSON格式的數據。@RestControllerAdvice, 默認返回json數據，方法不需要加@ResponseBody.
參考文章:
https://blog.csdn.net/q736317048/article/details/110352323