ADD download functionality

src/main/java/com/ddf/vodsystem/controllers/DownloadController.java

@@ -0,0 +1,48 @@
+package com.ddf.vodsystem.controllers;
+
+import com.ddf.vodsystem.exceptions.JobNotFinished;
+import com.ddf.vodsystem.exceptions.JobNotFound;
+import com.ddf.vodsystem.services.DownloadService;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.core.io.Resource;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+public class DownloadController {
+    private final DownloadService downloadService;
+
+    @Autowired
+    public DownloadController(DownloadService downloadService) {
+        this.downloadService = downloadService;
+    }
+
+    @GetMapping("/download/{filename}")
+    public ResponseEntity<Resource> downloadFile(@PathVariable String filename) {
+        Resource resource = downloadService.download(filename);
+
+        if (resource == null || !resource.exists()) {
+            return ResponseEntity.notFound().build();
+        }
+
+        return ResponseEntity.ok()
+                .header(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename=\"" + resource.getFilename() + "\"")
+                .contentType(MediaType.APPLICATION_OCTET_STREAM)
+                .body(resource);
+    }
+
+    @ExceptionHandler(JobNotFound.class)
+    public ResponseEntity<String> handleFileNotFound(JobNotFound ex) {
+        return ResponseEntity.status(404).body(ex.getMessage());
+    }
+
+    @ExceptionHandler(JobNotFinished.class)
+    public ResponseEntity<String> handleJobNotFinished(JobNotFinished ex) {
+        return ResponseEntity.status(404).body(ex.getMessage());
+    }
+}

src/main/java/com/ddf/vodsystem/exceptions/JobNotFinished.java

@@ -0,0 +1,7 @@
+package com.ddf.vodsystem.exceptions;
+
+public class JobNotFinished extends RuntimeException {
+    public JobNotFinished(String message) {
+        super(message);
+    }
+}

src/main/java/com/ddf/vodsystem/exceptions/JobNotFound.java

@@ -0,0 +1,7 @@
+package com.ddf.vodsystem.exceptions;
+
+public class JobNotFound extends RuntimeException {
+    public JobNotFound(String message) {
+        super(message);
+    }
+}

src/main/java/com/ddf/vodsystem/services/DownloadService.java

@@ -0,0 +1,38 @@
+package com.ddf.vodsystem.services;
+
+import com.ddf.vodsystem.entities.JobStatus;
+import com.ddf.vodsystem.exceptions.JobNotFinished;
+import com.ddf.vodsystem.exceptions.JobNotFound;
+import com.ddf.vodsystem.tools.Job;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.core.io.FileSystemResource;
+import org.springframework.core.io.Resource;
+import org.springframework.stereotype.Service;
+
+import java.io.File;
+
+@Service
+public class DownloadService {
+
+    private final JobService jobService;
+
+    @Autowired
+    public DownloadService(JobService jobService) {
+        this.jobService = jobService;
+    }
+
+    public Resource download(String uuid) {
+        Job job = jobService.get(uuid);
+
+        if (job == null) {
+            throw new JobNotFound("Job doesn't exist");
+        }
+
+        if (job.getStatus() != JobStatus.FINISHED) {
+            throw new JobNotFinished("Job is not finished");
+        }
+
+        File file = job.getOutputFile();
+        return new FileSystemResource(file);
+    }
+}