在 Spring Boot Web Thymeleaf 应用程序中进行 AJAX 调用的正确方法是获取 getOutputStream() 已经为此响应调用

Posted 2023-02-26

【中文标题】在 Spring Boot Web Thymeleaf 应用程序中进行 AJAX 调用的正确方法是获取 getOutputStream() 已经为此响应调用

【英文标题】：What is correct way to make AJAX call in Spring Boot web Thymeleaf application Getting getOutputStream() has already been called for this response

【发布时间】：2019-10-27 05:02:28

【问题描述】：

我正在开发基于 Spring Boot 的 Web 应用程序并在前端使用 Thymeleaf。我需要进行 AJAX 调用，发布从 AJAX 调用返回的数据和成功显示数据。

下面是调用Controller方法的AJAX调用

          var myObject = new Object();
          myObject.acctTypeValue = 22;
          myObject.amtBalance = "121334";
          myObject.custNo="12121";
          myObject.userId="2345rest";
          
        $.ajax(
            url : '/testDocWeb/forwardToCallingSystem',
            type :'POST',
            data : myObject,
            dataType:'html',
            cache: false,
                 timeout: 600000,
            success : function(data)                
                alert('Data: '+JSON.stringify(data));
            ,
            error : function(request,error)
            
                alert("Error : "+JSON.stringify(request));
            
        );

下面是 Spring MVC 控制器：-

    @PostMapping(path="/forwardToCallingSystem")
      public @ResponseBody DummuyResponse forwardToCallingSystem(@ModelAttribute DummyInput dummyInput,Model model, HttpServletRequest request) 
         log.info("Inside forwardToCallingSystem method." );
         DummuyResponse dummyResponse = new DummuyResponse ();
         dummyResponse .setDocId("756");
         dummyResponse .setReasonCode('0');
         dummyResponse .setReturnCode(100);
         dummyResponse .setStatusCode(200);
         return dummyResponse ;

下面是我要返回的模型对象：-

            @Data
            @JsonIgnoreProperties(ignoreUnknown = true)
            public class DummyResponse implements Serializable 
            private static final long serialVersionUID = -8191562770215698813L;
            private int statusCode;
            private char reasonCode;
            private int returnCode;
            private String docId;

我不确定出了什么问题，但在进行 AJAX 调用时出现以下错误：-

    [ERROR]~2019-06-12-10.32.54.030CDT~~~~~~ o.a.c.c.C.[.[localhost] Exception Processing ErrorPage[errorCode=0, location=/error]
    org.springframework.web.util.NestedServletException: Request processing failed; nested exception is java.lang.IllegalStateException: getOutputStream() has already been called for this response
        at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1013)
        at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:908)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:660)
        at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:882)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
        at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:712)
        at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:580)
        at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:516)
        at org.apache.catalina.core.StandardHostValve.custom(StandardHostValve.java:388)
        at org.apache.catalina.core.StandardHostValve.status(StandardHostValve.java:253)
        at org.apache.catalina.core.StandardHostValve.throwable(StandardHostValve.java:348)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:173)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
        at net.rakugakibox.spring.boot.logback.access.tomcat.LogbackAccessTomcatValve.invoke(LogbackAccessTomcatValve.java:91)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
        at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:408)
        at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
        at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:834)
        at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1415)
        at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
        at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
        at java.lang.Thread.run(Thread.java:745)
    Caused by: java.lang.IllegalStateException: getOutputStream() has already been called for this response
 

我只是在为普通 Spring MVC 制作 AJAX 调用表单 Thymeleaf 网页时遇到问题。它工作正常。任何帮助将不胜感激

【参考方案1】：

在您的 ajax 请求中，您使用的是dataType:'html'，但是根据jQuery’s Ajax-Related Methods Description，您从控制器返回了一个对象

// The type of data we expect back
dataType : "html"

将您的 ajax 请求更新为

$.ajax(
        url : '/testDocWeb/forwardToCallingSystem',
        type :'POST',
        data : myObject,
        cache: false,
        timeout: 600000,
        success : function(data)                
            alert('Data: ' + JSON.stringify(data));
        ,
        error : function(request,error) 
            alert("Error : " + JSON.stringify(request));
        
    );

另外，this Post 也会有所帮助。

【讨论】：

感谢您的回答。