ArrayList cannot be cast to org.springframework.ba

2020-03-26 08:51发布

问题:

I want to send a list from rest client to rest web service which will start a job in Spring Batch. Is that possible or must I save the list in database/flatfile before start the job and read the input values from database/flatfile? I guess someone pointed how do it in certain Jira issue (see below) but I couldn't figure out at least a basic idea how to move forward. I placed below my controller and how I am trying to cast it to JobParameter. I placed the Jira link and the possible direction perhaps I should take but I really didn't understand the suggestion in this Jira issue. I added below the SoapUi client and finally I pasted at the bottom my entire error log.

My Controller:

@RequestMapping(value = "runit/family", method = RequestMethod.POST)
       public void handle(@RequestBody List<Person> myFamily) throws Exception {
              System.out.println(myFamily); //until here, it is fine

              JobParameters jobParameters = new JobParametersBuilder()
                           .addParameter("parametersReceived", (JobParameter) myFamily)
                           .addLong("time", System.currentTimeMillis()).toJobParameters();

              jobLauncher.run(job, jobParameters);
       }

SoapUi (post):

[{"firstName":"aa","lastName":"bb"}]

Pojo

public class Person {

    private String lastName;
    private String firstName;
    ...getters and setters

Possible way to work but I am really confused about this Jira issue. Honestly, I was expecting some way more simple like I am trying with JobParameter

https://jira.spring.io/browse/BATCH-966 (this suggestion is from 2009. Probably some more up-to-date technique is available)
<bean class="MyItemReader">
<property name="dynamicValuesHashMap" ref="map"/>
...
</bean>

<bean class="MyLauncher">
<property name="dynamicValuesHashMap" ref="map"/>
...
</bean>

The entire error:

java.lang.ClassCastException: java.util.ArrayList cannot be cast to org.springframework.batch.core.JobParameter

       at hello.BatchController.handle(BatchController.java:42)

       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:497)

       at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:221)

       at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:137)

       at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:110)

       at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:776)

       at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:705)

       at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)

       at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:959)

       at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:893)

       at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:967)

       at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:869)

       at javax.servlet.http.HttpServlet.service(HttpServlet.java:648)

       at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:843)

       at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)

       at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)

       at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)

       at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)

       at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)

       at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)

       at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:77)

       at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)

       at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)

       at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)

       at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:85)

       at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)

       at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)

       at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)

       at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)

       at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)

       at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)

       at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142)

       at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)

       at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)

       at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:518)

       at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1091)

       at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:668)

       at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1521)

       at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1478)

       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)

回答1:

Batch jobs are meant to be Time based not Event based. So, you can't pass the information from Rest service to your Job instance. Before you trigger the job in your controller method either write the list in temporary flat file or store it in a database, from where your Job can read it.



回答2:

If you look at actual schema which stores meta data for spring batch you will see list of available types supported by job to be parameters (there is string_val, date_val, long_val, double_val). So when job is started each job parameter is persisted in DB with key_name as name of parameter and value stored in one of mentioned _val tables. type_cd gives a hint which type was used.

Also documentation for JobParameter gives a hint what can be used as job parameter:

Domain representation of a parameter to a batch job. Only the following types can be parameters: String, Long, Date, and Double. The identifying flag is used to indicate if the parameter is to be used as part of the identification of a job instance.

I think best way would be either to create table in DB which stores list of parameters and pass id of that record as JobParameter or to serialize list to json and pass it as String in job as JobParameter. If you go with second option be aware that string_val is stored in DB as varchar 250 so limit is 250 characters.