10-download-and-upload.afc

[chapter Download and Upload]

[section 1 minute example: download]

The following example shows how to expose the file to be downloaded to its client.

Again, see how simple this code is:

[java]
@Resource
public class ProfileController {

	public File picture(Profile profile) {
		return new File("/path/to/the/picture." + profile.getId()+ ".jpg");
	}
}
[/java]

[section Adding more info to download]

If you want to add more information to download, you can return a FileDownload:

[java]
@Resource
public class ProfileController {

	public Download picture(Profile profile) {
		File file = new File("/path/to/the/picture." + profile.getId()+ ".jpg");
		String contentType = "image/jpg";
		String filename = profile.getName() + ".jpg";
		
		return new FileDownload(file, contentType, filename); 
	}
}
[/java]

You can also use the %%InputStreamDownload%% implementation to work with Streams or
%%ByteArrayDownload%% to work with byte array (since 3.2-snapshot).

[section Upload]

The upload component is optional. To enable this feature, you only need to add the %%commons-upload%% library in your classpath.

Since VRaptor 3.2, if you're in a container that implements the JSR-315 (Servlet 3.0), you don't need %%commons-upload%% nor
 %%commons-io%% libraries because the servlet container already have this.

[section 1 minute example: upload]

The first example is based on the multipart upload feature.

[java]
@Resource
public class ProfileController {

	private final ProfileDao dao;

	public ProfileController(ProfileDao dao) {
		this.dao = dao;
	}

	public void updatePicture(Profile profile, UploadedFile picture) {
		dao.update(picture.getFile(), profile);
	}
}
[/java]

[section More about Upload]

UploadedFile returns the file content as a InputStream. If you want to save this file on disk in an 
easy way, you can use the %%commons-io IOUtils%%:
[java]
	public void updatePicture(Profile profile, UploadedFile picture) {
		File pictureOnDisk = new File();	
		IOUtils.copyLarge(picture.getFile(), new FileOutputStream(pictureOnDisk));
		dao.atribui(pictureOnDisk, profile);
	}
[/java]

[section Overriding upload settings]

You can also change the default upload settings overriding the class %%MultipartConfig%%. In example below, the size limit of upload is changed.

[java]@Component
@ApplicationScoped
public class CustomMultipartConfig extends DefaultMultipartConfig {

    public long getSizeLimit() {
        return 50 * 1024 * 1024; // 50MB
    }

}[/java]

[section Changes in form]

You need to add the parameter %%enctype%% with %%multipart/form-data%% value. Without this attribute, the browser cannot upload files:

[xml]<form action="minha-action" enctype="multipart/form-data">[/xml]

[section Validating upload]

When the maximum size for uploaded file exceeds the configured value, VRaptor add a message on the Validator object.