The Design Of Unix Operating System PDF

I got this google drive link from somewhere for this book - https://drive.google.com/file/d/0B3XGoURu-QZEbjhhTnJibExWQlU/edit

OKHTTP S3 FIle upload via Signed URL

Here is the sample code in java to upload a file to S3 via OK HTTP client. We will need two dependencies -

1. okhttp-2.4.0.jar
2. okio-1.4.0.jar

Other than this we will need this piece of code to upload the file - 

package okhttpfileupload;

import java.io.File;

import java.io.IOException;

import com.squareup.okhttp.MediaType;

import com.squareup.okhttp.OkHttpClient;

import com.squareup.okhttp.Request;

import com.squareup.okhttp.RequestBody;

import com.squareup.okhttp.Response;

public class Upload {

final OkHttpClient client = new OkHttpClient();

final String ENDPOINT = "https://bucket.s3-region.amazonaws.com/filename.jpg?AWSAccessKeyId=ACCESSKEYHERE&Content-Type=image%2Fjpg&Expires=1437757726&Signature=SIGNATUREHERE&x-amz-acl=public-read";

String imagePath = "/home/devendra/Desktop/pokemon.jpg";

public static void main(String[] args) throws IOException {

new Upload().uploadFile();

}

private void uploadFile() throws IOException {

File file = new File(imagePath);

   Request request = new Request.Builder()

   .header("Content-Type", "image/jpg")

        .url(ENDPOINT)

       .put(RequestBody.create(MediaType.parse("image/jpg"), file))

       .build();

   System.out.println("Upload started.");

   Response response = client.newCall(request).execute();

   System.out.println("Request complete.");

   if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);

   System.out.println(response.body().string());

}

}

All you have to do is change the imagePath and ENDPOINT.

Happy Coding!