Update an image to product

[tamanhtp]

Thanks for your sample about createProduct. Now I'm struggle with update image of a product.
Uploading to the media library is not part of woocommerce API. So I need to upload image to Media first then get the imageID/URL.
But dont know how to pass the imageID/URL to a product.

Product product = getProductbyID(products,ID);
            ProductImage pdImage = new ProductImage();
            pdImage.setSrc("https://lunpetshop.com/wp-content/uploads/2025/03/z6379545848529_082fa96a13d94801416feb84de1e0824.jpg");
            pdImage.src("https://lunpetshop.com/wp-content/uploads/2025/03/z6379545848529_082fa96a13d94801416feb84de1e0824.jpg");
            List<ProductImage> ProductImages = product.getImages();
            ProductImages.add(pdImage);
            product.setImages(ProductImages);
            product.images(ProductImages);
            productsApi.updateProductById(ID, product);

The product don't have images, so getImages return null and cannot set or add.
When I create new List ProductImage and add to product, it return message "not type Integer".
@bartsli Please guild me some clue. Update image is the lastest step to complete.
Thanks in advance.

[bartsli]

Re: Update an image to product

Hi @tamanhtp! I can see the issues in your code. Let me help you fix them.

Problems in your current code:

1. Null pointer issue: product.getImages() returns null when no images exist.
2. Redundant method calls: You're using both pdImage.setSrc() and pdImage.src() - the second one is a fluent method that returns the object, not a setter.
3. Incorrect method calls: You're using product.images() instead of product.setImages().
4. Manual list management: You're manually creating and managing the images list.

Correct solution:

// Get the product
Product product = getProductbyID(products, ID);

// Create new product image
ProductImage pdImage = new ProductImage();
pdImage.setSrc("https://lunpetshop.com/wp-content/uploads/2025/03/z6379545848529_082fa96a13d94801416feb84de1e0824.jpg");

// Use addImagesItem() - it handles null lists automatically
product.addImagesItem(pdImage);

// Update the product
productsApi.updateProductById(ID, product);

Key points:

• Use addImagesItem() instead of manually managing the list - this method automatically initializes the list if it's null.
• Use only setSrc() - remove the redundant pdImage.src() call (this is a fluent method, not a setter).
• Use setImages() instead of images() - images() is a fluent method, setImages() is the setter.
• No need to manually create List<ProductImage> - the addImagesItem() method handles this.

If you have the WordPress media library image ID:

ProductImage pdImage = new ProductImage();
pdImage.setId(123); // WordPress media library image ID
pdImage.setSrc("https://lunpetshop.com/wp-content/uploads/2025/03/z6379545848529_082fa96a13d94801416feb84de1e0824.jpg");

product.addImagesItem(pdImage);

The "not type Integer" error occurs because WooCommerce API expects proper field types when updating product images. Using addImagesItem() ensures the correct structure is maintained.

Let me know if you need any clarification! :-)

[tamanhtp]

Hi, thank for quickly reply.
Using exactly what you advice but still response message

pdImage.setId(123); >> message response: not of type String
pdImage.setSrc("https://..."); >> message response: not of type integer

One more thing. We must using Wordpress API to upload image and get ID/ URL?
Woocommerce API cannot do it?

[bartsli]

Hi @tamanhtp,

Thanks for your follow-up and for sharing the error details.

The error message "rest_invalid_param" with "not type integer" means the WooCommerce server is rejecting your request because the id field in your product image is not being sent as an integer (it might be a string or incorrectly formatted in the JSON).

Since you’re already using the recommended code and still getting this error, the next step is to check exactly what is being sent to the WooCommerce API and what the server responds with. Sometimes, even if the Java object is correct, the JSON serialization or the HTTP request might not be.

---

🔍 What to do next

1. Enable debug mode in your client (if not already enabled):

   WooCommerceApiClient apiClient = new WooCommerceApiClient(true);

2. Run your code and copy here:

   • The code fragment where you create and add the ProductImage to the product.
   • The full request and response from the debug logs (everything printed to the console when debug mode is enabled).

---

Once you share these details, I’ll be able to analyze the exact JSON being sent and the server’s response, and we’ll quickly find the root cause of the type error.

Thanks! Looking forward to your update so we can solve this together.

[tamanhtp]

Set debug mode and I'm figure out. All 4 params cannot left as null: Alt, Name, ID, Src. So I need to set all 4 param.
About the process of upload image: We must using Wordpress API to upload image and get ID + URL?
Woocommerce API cannot upload an image?

Product product = getProductbyID(products,28722);
            ProductImage pdImage = new ProductImage();
            pdImage.setAlt("z6379545848529_082fa96a13d94801416feb84de1e0824.jpg");
            pdImage.setName("z6379545848529_082fa96a13d94801416feb84de1e0824.jpg");
            pdImage.setId(28707);
            pdImage.setSrc("https://lunpetshop.com/wp-content/uploads/2025/03/z6379545848529_082fa96a13d94801416feb84de1e0824.jpg");
            product.addImagesItem(pdImage);
            productsApi.updateProductById(28722, product);

Many thanks.

[bartsli]

Hi @tamanhtp,

Thanks for your update and for sharing your solution!

To answer your question: WooCommerce REST API does not support uploading image files directly. You always need to upload the image first to the WordPress media library (using the WordPress REST API), and then use the returned image ID and URL when updating the product via WooCommerce API.

Steps:

1. Upload the image to WordPress using /wp-json/wp/v2/media (POST, multipart/form-data).
2. Get the id and source_url from the response.
3. Use these values in your product image object (id, src, name, alt all required).

Example:

ProductImage image = new ProductImage();
image.setId(imageId); // from WP media response
image.setSrc(imageUrl); // from WP media response
image.setName("your-image.jpg");
image.setAlt("Alt text");
product.addImagesItem(image);
productsApi.updateProductById(productId, product);

Summary:

• You can't upload images directly with WooCommerce API :-(
• Always set all 4 fields: id, src, name, alt.
• Upload to WordPress first, then update the product.

If you need a Java example for uploading to WordPress, let me know.

Thanks for helping improve the docs :-)