Add the backend logic to export all users to .csv

dmp-backend/web/src/main/java/eu/eudat/controllers/Users.java

@@ -103,6 +103,12 @@ public class Users extends BaseController {
         userManager.deleteDOIToken(principal);
         return ResponseEntity.status(HttpStatus.OK).body(new ResponseItem<UserProfile>().status(ApiMessageCode.NO_MESSAGE));
     }
+    
+    @RequestMapping(method = RequestMethod.GET, value = {"/getCsv"})
+    public @ResponseBody
+    ResponseEntity exportCsv(@ClaimedAuthorities(claims = {ADMIN}) Principal principal) throws Exception {
+        return userManager.exportToCsv(principal);
+    }
 }
 
 	

dmp-backend/web/src/main/java/eu/eudat/logic/managers/UserManager.java

@@ -29,20 +29,35 @@ import eu.eudat.models.data.security.Principal;
 import eu.eudat.models.data.userinfo.UserListingModel;
 import eu.eudat.models.data.userinfo.UserProfile;
 import eu.eudat.queryable.QueryableList;
+import eu.eudat.types.Authorities;
+
 import org.json.JSONObject;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.core.env.Environment;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
 import org.springframework.stereotype.Component;
 import org.w3c.dom.Document;
 import org.w3c.dom.Element;
 
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
 import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.nio.file.Files;
 import java.time.Instant;
 import java.util.*;
 import java.util.stream.Collectors;
 
 @Component
 public class UserManager {
+	private static final Logger logger = LoggerFactory.getLogger(UserManager.class);
 
 	private ApiContext apiContext;
 	private ZenodoCustomProvider zenodoCustomProvider;
@@ -168,4 +183,44 @@ public class UserManager {
 		settings.put("expirationDate",  0);
 		this.updateSettings(settings, principal);
 	}
+	
+	public ResponseEntity<byte[]> exportToCsv(Principal principal) throws IOException {
+        if (!principal.getAuthz().contains(Authorities.ADMIN))
+            throw new UnauthorisedException();
+        
+        List<UserInfo> users = this.apiContext.getOperationsContext().getDatabaseRepository().getUserInfoDao().asQueryable().toList();
+        StringBuilder resultBuilder = new StringBuilder();
+        resultBuilder.append("User Id").append(",").append("User Name").append(",").append("User Email").append("\n");
+        users.stream().forEach(user -> resultBuilder.append(user.getId().toString()).append(",")
+        		.append(user.getName()).append(",")
+        		.append(user.getEmail()).append("\n"));
+        String result = resultBuilder.toString();
+        String fileName = "Users_dump";//dmp.getLabel();
+        fileName = fileName.replaceAll("[^a-zA-Z0-9+ ]", "");
+        String uuid = UUID.randomUUID().toString();
+        File file = new File(this.environment.getProperty("temp.temp") + uuid + ".csv");
+        OutputStream output = new FileOutputStream(file);
+        try {
+//            mapper.writeValue(file, rdaExportModel);
+            output.write(result.getBytes());
+            output.flush();
+            output.close();
+        } catch (IOException e) {
+            logger.error(e.getMessage(), e);
+        }
+
+        InputStream resource = new FileInputStream(file);
+        HttpHeaders responseHeaders = new HttpHeaders();
+        responseHeaders.setContentLength(file.length());
+        responseHeaders.setContentType(MediaType.APPLICATION_OCTET_STREAM);
+        responseHeaders.set("Content-Disposition", "attachment;filename=" + fileName + ".csv");
+        responseHeaders.set("Access-Control-Expose-Headers", "Content-Disposition");
+        responseHeaders.get("Access-Control-Expose-Headers").add("Content-Type");
+
+        byte[] content = org.apache.poi.util.IOUtils.toByteArray(resource);
+        resource.close();
+        Files.deleteIfExists(file.toPath());
+        return new ResponseEntity<>(content, responseHeaders, HttpStatus.OK);
+    }
+	
 }