Added checks for response code for the olog http client for attachments.

Author: Peyton-Hill-CLS

app/logbook/olog/client-es/src/main/java/org/phoebus/olog/es/api/OlogHttpClient.java

@@ -469,6 +469,10 @@ public InputStream getAttachment(Long logId, String attachmentName) {
                     .GET()
                     .build();
             HttpResponse<InputStream> response = httpClient.send(request, HttpResponse.BodyHandlers.ofInputStream());
+            if(response.statusCode() >= 300) {
+                LOGGER.log(Level.WARNING, "failed to obtain attachment: " + new String(response.body().readAllBytes()));
+                return null;
+            }
             return response.body();
         } catch (Exception e) {
             LOGGER.log(Level.WARNING, "failed to obtain attachment", e);

app/logbook/olog/ui/src/main/java/org/phoebus/logbook/olog/ui/AttachmentsViewController.java

@@ -278,7 +278,7 @@ private void showPreview(Attachment attachment) {
      * @param attachment The image {@link Attachment} selected by user.
      */
     private void showImagePreview(Attachment attachment) {
-        if (attachment.getFile() != null) {
+        if (attachment.getFile() != null && attachment.getFile().exists()) {
             // Load image data off UI thread...
             JobManager.schedule("Show image attachment", monitor -> {
                 try {

app/logbook/olog/ui/src/main/java/org/phoebus/logbook/olog/ui/SingleLogEntryDisplayController.java

@@ -33,6 +33,7 @@
 import org.phoebus.ui.web.HyperLinkRedirectListener;
 
 import java.io.File;
+import java.io.InputStream;
 import java.nio.file.Files;
 import java.nio.file.StandardCopyOption;
 import java.text.MessageFormat;
@@ -260,8 +261,11 @@ private void fetchAndSetAttachments() {
 
                 File attachmentFile = new File(attachmentsDirectory, attachment.getId() + fileExtension);
                 if (!attachmentFile.exists()) {
-                    Files.copy(logClient.getAttachment(logEntry.getId(), attachment.getName()), attachmentFile.toPath(), StandardCopyOption.REPLACE_EXISTING);
-                    attachmentFile.deleteOnExit();
+                    InputStream stream = logClient.getAttachment(logEntry.getId(), attachment.getName());
+                    if(stream != null) {
+                        Files.copy(stream, attachmentFile.toPath(), StandardCopyOption.REPLACE_EXISTING);
+                        attachmentFile.deleteOnExit();
+                    }
                 }
                 fileAttachment.setFile(attachmentFile);
                 attachmentList.add(fileAttachment);