Merge pull request #9256 from DSpace/backport-9248-to-dspace-7_x

[Port dspace-7_x] Return headers for HEAD request

dspace-server-webapp/src/main/java/org/dspace/app/rest/BitstreamRestController.java

@@ -138,6 +138,7 @@ public class BitstreamRestController {
                 .withBufferSize(BUFFER_SIZE)
                 .withFileName(name)
                 .withChecksum(bit.getChecksum())
+                .withLength(bit.getSizeBytes())
                 .withMimetype(mimetype)
                 .with(request)
                 .with(response);
@@ -167,6 +168,12 @@ public class BitstreamRestController {
             //Send the data
             if (httpHeadersInitializer.isValid()) {
                 HttpHeaders httpHeaders = httpHeadersInitializer.initialiseHeaders();
+
+                if (RequestMethod.HEAD.name().equals(request.getMethod())) {
+                    log.debug("HEAD request - no response body");
+                    return ResponseEntity.ok().headers(httpHeaders).build();
+                }
+
                 return ResponseEntity.ok().headers(httpHeaders).body(bitstreamResource);
             }
 

dspace-server-webapp/src/main/java/org/dspace/app/rest/utils/HttpHeadersInitializer.java

@@ -14,6 +14,7 @@ import static javax.mail.internet.MimeUtility.encodeText;
 import java.io.IOException;
 import java.util.Arrays;
 import java.util.Collections;
+import java.util.Objects;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
@@ -33,7 +34,6 @@ public class HttpHeadersInitializer {
 
     protected final Logger log = LoggerFactory.getLogger(this.getClass());
 
-    private static final String METHOD_HEAD = "HEAD";
     private static final String MULTIPART_BOUNDARY = "MULTIPART_BYTERANGES";
     private static final String CONTENT_TYPE_MULTITYPE_WITH_BOUNDARY = "multipart/byteranges; boundary=" +
         MULTIPART_BOUNDARY;
@@ -144,6 +144,9 @@ public class HttpHeadersInitializer {
         if (checksum != null) {
             httpHeaders.put(ETAG, Collections.singletonList(checksum));
         }
+        if (Objects.nonNull((Long.valueOf(this.length)))) {
+            httpHeaders.put(HttpHeaders.CONTENT_LENGTH, Collections.singletonList(String.valueOf(this.length)));
+        }
         httpHeaders.put(LAST_MODIFIED, Collections.singletonList(FastHttpDateFormat.formatDate(lastModified)));
         httpHeaders.put(EXPIRES, Collections.singletonList(FastHttpDateFormat.formatDate(
             System.currentTimeMillis() + DEFAULT_EXPIRE_TIME)));
@@ -165,16 +168,14 @@ public class HttpHeadersInitializer {
 
         httpHeaders.put(HttpHeaders.ACCESS_CONTROL_EXPOSE_HEADERS,
                         Collections.singletonList(HttpHeaders.ACCEPT_RANGES));
+
+        // distposition may be null here if contentType is null
+        if (!isNullOrEmpty(disposition)) {
             httpHeaders.put(CONTENT_DISPOSITION, Collections.singletonList(String.format(CONTENT_DISPOSITION_FORMAT,
                                                                                          disposition,
                                                                                          encodeText(fileName))));
-        log.debug("Content-Disposition : {}", disposition);
-
-        // Content phase
-        if (METHOD_HEAD.equals(request.getMethod())) {
-            log.debug("HEAD request - skipping content");
-            return null;
         }
+        log.debug("Content-Disposition : {}", disposition);
 
         return httpHeaders;
 

dspace-server-webapp/src/test/java/org/dspace/app/rest/BitstreamRestControllerIT.java

@@ -205,6 +205,18 @@ public class BitstreamRestControllerIT extends AbstractControllerIntegrationTest
         }
         context.restoreAuthSystemState();
 
+            //** WHEN **
+            // we want to know what we are downloading before we download it
+            getClient().perform(head("/api/core/bitstreams/" + bitstream.getID() + "/content"))
+                       //** THEN **
+                       .andExpect(status().isOk())
+
+                       //The Content Length must match the full length
+                       .andExpect(header().longValue("Content-Length", bitstreamContent.getBytes().length))
+                       .andExpect(header().string("Content-Type", "text/plain;charset=UTF-8"))
+                       .andExpect(header().string("ETag", "\"" + bitstream.getChecksum() + "\""))
+                       .andExpect(content().bytes(new byte[] {}));
+
             //** WHEN **
             //We download the bitstream
             getClient().perform(get("/api/core/bitstreams/" + bitstream.getID() + "/content"))
@@ -231,7 +243,7 @@ public class BitstreamRestControllerIT extends AbstractControllerIntegrationTest
                        .andExpect(status().isNotModified());
 
             //The download and head request should also be logged as a statistics record
-            checkNumberOfStatsRecords(bitstream, 2);
+            checkNumberOfStatsRecords(bitstream, 3);
     }
 
     @Test