Download text file from JAX-RS

In JAX-RS, for user to download a file, annotate the method with @Produces("text/plain") :

Put @Produces(“text/plain”) on service method, with a Response return type. It means the output is a text file.
Set “Content-Disposition” in Response header to tell browser pop up a download box for user to download.

1. Download File in JAX-RS

See a full example to download a text file in JAX-RS.

import java.io.File;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.Response;
import javax.ws.rs.core.Response.ResponseBuilder;
 
@Path("/file")
public class FileService {
 
	private static final String FILE_PATH = "c:\\file.log";
 
	@GET
	@Path("/get")
	@Produces("text/plain")
	public Response getFile() {
 
		File file = new File(FILE_PATH);
 
		ResponseBuilder response = Response.ok((Object) file);
		response.header("Content-Disposition",
			"attachment; filename=\"file_from_server.log\"");
		return response.build();
 
	}
 
}