Part 5.4

src/main/java/io/zipcoder/tc_spring_poll_application/controller/PollController.java

 package io.zipcoder.tc_spring_poll_application.controller;
 
 import io.zipcoder.tc_spring_poll_application.domain.Poll;
+import io.zipcoder.tc_spring_poll_application.excepection.ResourceNotFoundException;
 import io.zipcoder.tc_spring_poll_application.repository.PollRepository;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.http.HttpStatus;
 
     @RequestMapping(value="/polls/{pollId}", method=RequestMethod.GET)
     public ResponseEntity<?> getPoll(@PathVariable Long pollId) {
+        verifyPoll(pollId);
         Poll p = pollRepository.findOne(pollId);
         return new ResponseEntity<> (p, HttpStatus.OK);
     }
 
     @RequestMapping(value="/polls/{pollId}", method=RequestMethod.PUT)
     public ResponseEntity<?> updatePoll(@RequestBody Poll poll, @PathVariable Long pollId) {
-        // Save the entity
+        verifyPoll(pollId);
         Poll p = pollRepository.save(poll);
         return new ResponseEntity<>(HttpStatus.OK);
     }
 
     @RequestMapping(value="/polls/{pollId}", method=RequestMethod.DELETE)
     public ResponseEntity<?> deletePoll(@PathVariable Long pollId) {
+        verifyPoll(pollId);
         pollRepository.delete(pollId);
         return new ResponseEntity<>(HttpStatus.OK);
     }
 
+    private void verifyPoll(Long pollId) {
+        Poll poll = pollRepository.findOne(pollId);
+        if(poll == null) throw new ResourceNotFoundException();
+    }
 
 }

src/main/java/io/zipcoder/tc_spring_poll_application/error/ErrorDetail.java

+package io.zipcoder.tc_spring_poll_application.error;
+
+public class ErrorDetail {
+
+    private String title;
+    private int status;
+    private String detail;
+    private long timeStamp;
+    private String developerMessage;
+
+    public ErrorDetail() {
+    }
+
+    public ErrorDetail(String title, int status, String detail, long timeStamp, String developerMessage) {
+        this.title = title;
+        this.status = status;
+        this.detail = detail;
+        this.timeStamp = timeStamp;
+        this.developerMessage = developerMessage;
+    }
+
+    public String getTitle() {
+        return title;
+    }
+
+    public void setTitle(String title) {
+        this.title = title;
+    }
+
+    public int getStatus() {
+        return status;
+    }
+
+    public void setStatus(int status) {
+        this.status = status;
+    }
+
+    public String getDetail() {
+        return detail;
+    }
+
+    public void setDetail(String detail) {
+        this.detail = detail;
+    }
+
+    public long getTimeStamp() {
+        return timeStamp;
+    }
+
+    public void setTimeStamp(long timeStamp) {
+        this.timeStamp = timeStamp;
+    }
+
+    public String getDeveloperMessage() {
+        return developerMessage;
+    }
+
+    public void setDeveloperMessage(String developerMessage) {
+        this.developerMessage = developerMessage;
+    }
+}

src/main/java/io/zipcoder/tc_spring_poll_application/excepection/ResourceNotFoundException.java

 package io.zipcoder.tc_spring_poll_application.excepection;
 
-public class ResourceNotFoundException {
-}
+import org.springframework.http.HttpStatus;
+import org.springframework.web.bind.annotation.ResponseStatus;
+
+@ResponseStatus(HttpStatus.NOT_FOUND)
+public class ResourceNotFoundException extends RuntimeException{
+
+    public ResourceNotFoundException() {
+    }
+
+    public ResourceNotFoundException(String message) {
+        super(message);
+    }
+
+    public ResourceNotFoundException(String message, Throwable cause) {
+        super(message, cause);
+    }
+}

src/main/java/io/zipcoder/tc_spring_poll_application/excepection/RestExceptionHandler.java

+package io.zipcoder.tc_spring_poll_application.excepection;
+
+import io.zipcoder.tc_spring_poll_application.error.ErrorDetail;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.ControllerAdvice;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+
+import javax.servlet.http.HttpServletRequest;
+import java.util.Date;
+
+@ControllerAdvice
+public class RestExceptionHandler {
+
+    @ExceptionHandler(ResourceNotFoundException.class)
+    public ResponseEntity<?> handleResourceNotFoundException(ResourceNotFoundException rnfe, HttpServletRequest request) {
+        ErrorDetail errorDetail = new ErrorDetail();
+        errorDetail.setTimeStamp(new Date().getTime());
+        errorDetail.setDeveloperMessage(rnfe.getMessage());
+        errorDetail.setDetail(rnfe.getCause().getMessage());
+
+        return new ResponseEntity<>(errorDetail, HttpStatus.NOT_FOUND);
+    }
+
+
+}