无法显示XML数据

Question

嗨，我需要同时显示xml和json数据。我可以通过JaxB在本地看到这一点，但在服务器上看不到相同的代码。当我把它部署到服务器时，我得到了这个错误。我不知道如何解决这个错误。无法解决这一点，尝试了很多但没有发生，在本地一切都很好，但当涉及到服务器它显示不同的异常。

错误500:org.springframework.web.util.NestedServletException：请求处理失败；嵌套异常为org.springframework.http.converter.httpmessageConversionException：无法实例化类[class com.rest.model.exerceiseInstructionsList]的JAXBContext：null；嵌套异常是javax.xml.bind.jaxbException-与链接异常：[com.sun.xml.internal.bind.v2.runtime.IllegalAnnotationException：1 counts of IllegalAnnotationExceptions类有两个同名属性“ExpresseList”此问题与以下位置相关：at public java.util.list com.rest.model.ExpresseInstructionsList.getExpresseList（）at com.rest.model.ExpresseInstructionsList此问题与以下位置相关：at public java.util.list com.rest.model.ExpresseInstructionsList com.rest.model.ExpresseInstructionsList

我的控制器是

@Controller
@RequestMapping("/")
public class ExerciseController {

    @Autowired
    private ExerciseService exerciseService;


    private static final Logger logger = LoggerFactory.getLogger(ExerciseController.class);

    @Consumes
    @Produces
    @RequestMapping(value=OaesRestURIConstants.GET_EXERCISE_ALL,method=RequestMethod.GET,produces={"application/json"})
    public @ResponseBody List<ExerciseInstructions> getAllExercise()throws Exception{


        logger.info("Start getAllExercises.");

        System.out.println("<<<<<<<<<<<<<<<<<--------------Coming Inside List Exercise Controller----------->>>>>>>>>>>");
        List<ExerciseInstructions> listExercise = new ArrayList<ExerciseInstructions>();
        //ExerciseInstructionsList exe = new ExerciseInstructionsList();


        /*This list contains Exercise Instructions Data*/
        listExercise = exerciseService.getAllExercise();

        /*here i kept the list in     ExerciseInstructionsList    list so that i can fetch xml data also and can show the list.*/
        //exe.setExerciseList(listExercise);

        return  listExercise;
    }



    @RequestMapping(value=OaesRestURIConstants.GET_EXERCISE_XML_ALL,method=RequestMethod.GET,produces={"application/xml"})
    public @ResponseBody ExerciseInstructionsList getAllXmlExercise()throws Exception{


        logger.info("Start getAllExercises.");

        System.out.println("<<<<<<<<<<<<<<<<<--------------Coming Inside List Exercise Controller----------->>>>>>>>>>>");
        List<ExerciseInstructions> listExercise = new ArrayList<ExerciseInstructions>();
        ExerciseInstructionsList exeList = new ExerciseInstructionsList();


        /*This list contains Exercise Instructions Data*/
        listExercise = exerciseService.getAllExercise();

        /*here i kept the list in     ExerciseInstructionsList    list so that i can fetch xml data also and can show the list.*/
        exeList.setExerciseList(listExercise);

        return  exeList;
    }

    @RequestMapping(value=OaesRestURIConstants.EXERCISE_SAVE,method=RequestMethod.POST)
    public @ResponseBody ExerciseInstructions saveExercise(@RequestBody ExerciseInstructions exerciseInstructions)throws Exception{

        logger.info("Start saveExercise.");
        exerciseService.saveExercise(exerciseInstructions);


        return exerciseInstructions;
    }



//@Consumes({"application/xml","application/json"})
   // @Produces({"application/xml","application/json"})
    @RequestMapping(value=OaesRestURIConstants.GET_EXERCISE_ID,method=RequestMethod.GET,produces={"application/xml","application/json"})
    public @ResponseBody ExerciseInstructions getExerciseById(@PathVariable("id") String exerciseId ) throws Exception{

        logger.info("Start getExerciseById. ID="+exerciseId);

        ExerciseInstructions exercise = null;



         try {
             exercise = exerciseService.getExerciseById(exerciseId);

              } catch (Exception e) {
               e.printStackTrace();
              }
        System.out.println("Coming Here>>>>>>>>>>>"+exercise);
        return exercise;
    //return exerciseService.getExerciseById(exerciseId);

    }


    @RequestMapping(value=OaesRestURIConstants.EXERCISE_DELETE,method=RequestMethod.PUT)
    public @ResponseBody ExerciseInstructions deleteById(@PathVariable("id") String exerciseId) throws Exception{

        logger.info("Start deleteExercise.");
        exerciseService.deleteExercise(exerciseId);

        return null;
    }

}

我的模型类是：

@XmlRootElement
@XmlAccessorType(XmlAccessType.FIELD)
public class ExerciseInstructions {}

我的模型列表类是：

@XmlRootElement(name="exerciseInstructions")
//@XmlSeeAlso({ExerciseInstructions.class})
@XmlAccessorType(XmlAccessType.FIELD)
public class ExerciseInstructionsList {

    public List<ExerciseInstructions> exerciseList;

    public List<ExerciseInstructions> getExerciseList() {
        return exerciseList;
    }

    public void setExerciseList(List<ExerciseInstructions> exerciseList) {
        this.exerciseList = exerciseList;
    }


}

所以，有谁能在这方面帮助我。
我想获取并查看xml和JSON。

Answer 1

当您仔细阅读错误消息时，您会看到原因：（为了更好的可读性，我对消息进行了格式化和高亮显示）

IllegalAnnotationExceptions类有两个同名属性“ExpresseList”
此问题与以下位置相关：在public java.util.list com.rest.model.ExpresseInstructionsList.getExpresseList（）com.rest.model.ExpresseInstructionsList
此问题与以下位置相关：在public java.util.list com.rest.model.ExpresseInstructionsList com.rest.model.ExpresseInstructionsList com.rest.model.ExpresseInstructionsList com.rest.model.ExpresseInstructionsList com.rest.model.ExpresseInstructionsList

因此，程序抱怨您的类exerceiseInstructionsList有两个属性可以映射到exerceiselist，这两个属性是getexerceiselist()和exerceiselist。

要解决此问题，可以将expresseList声明为private。

@XmlRootElement(name="exerciseInstructions")
@XmlAccessorType(XmlAccessType.FIELD)
public class ExerciseInstructionsList {
    private List<ExerciseInstructions> exerciseList;

    public List<ExerciseInstructions> getExerciseList() {
        return exerciseList;
    }

    public void setExerciseList(List<ExerciseInstructions> exerciseList) {
        this.exerciseList = exerciseList;
    }
}