halo-dev/halo · warning · ServerWebInputException

Policy name must not be blank

Error message

Policy name must not be blank

What it means

The compact constructor of UploadFromUrlRequest also validates policyName: it throws ServerWebInputException (HTTP 400) 'Policy name must not be blank' when policyName is null or whitespace. policyName is the metadata.name of the attachment storage policy the upload should use.

Solutions

1. Send a valid attachment policy metadata.name in policyName.
2. Fetch available policies first and ensure the chosen one exists before submitting.
3. On the client, require a non-empty policy selection before enabling upload.

Example fix

// before
{ "url": "https://example.com/file.png" } // 400: policyName blank

// after
{ "url": "https://example.com/file.png", "policyName": "default-policy" }

if (!StringUtils.hasText(policyName)) {
    return Mono.error(new ServerWebInputException("Policy name must not be blank"));
}

static boolean hasPolicyName(String p) { return StringUtils.hasText(p); }

When it happens

Trigger: POST upload-from-url with policyName omitted, null, or whitespace-only; passing a policy display name instead of its metadata.name; referencing a policy that was deleted so the caller leaves the field blank.

Common situations: Frontend default-policy selection not initialized; user cleared the policy dropdown; integration code assuming a hard-coded policy name that no longer exists.

Related errors

• Required url is missing.
• Invalid part of policyName
• Invalid part of file
• Required url is missing.
• urls must not be empty.

AI-assisted analysis of halo-dev/halo@d2f5165f9c (2026-08-14). Data as JSON: /api/errors/1b3c9660d3c8a7e0. Report an issue: GitHub.

Appendix: source

Thrown at application/src/main/java/run/halo/app/core/attachment/endpoint/AttachmentEndpoint.java:142

     * @param policyName storage policy {@code metadata.name}
     * @param groupName attachment group {@code metadata.name}
     * @param filename custom file name
     */
    public record UploadFromUrlRequest(
            @Schema(requiredMode = REQUIRED) URL url,

            @Schema(requiredMode = REQUIRED) String policyName,

            String groupName,

            String filename) {
        public UploadFromUrlRequest {
            if (Objects.isNull(url)) {
                throw new ServerWebInputException("Required url is missing.");
            }

            if (!StringUtils.hasText(policyName)) {
                throw new ServerWebInputException("Policy name must not be blank");
            }
        }
    }

    /** Multipart payload for uploading an attachment. */
    @Schema(types = "object")
    public interface IUploadRequest {

        /** Attachment file. */
        @Schema(requiredMode = REQUIRED)
        FilePart getFile();

        /** Storage policy {@code metadata.name}. */
        @Schema(requiredMode = REQUIRED)
        String getPolicyName();

        /** Attachment group {@code metadata.name}. */
        String getGroupName();

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