How to create ZIP files using list of Input streams?

Question

In my case I have to download images from the resources folder in my web app. Right now I am using the following code to download images through URL.

url = new URL(properties.getOesServerURL() + "//resources//WebFiles//images//" + imgPath);

filename = url.getFile();               

is = url.openStream();
os = new FileOutputStream(sClientPhysicalPath + "//resources//WebFiles//images//" + imgPath);

b = new byte[2048];

while ((length = is.read(b)) != -1) {
    os.write(b, 0, length);
}

But I want a single operation to read all images at once and create a zip file for this. I don't know so much about the use of sequence input streams and zip input streams so if it is possible through these, please let me know.

Answer 1

The only way I can see you being able to do this is something like the following:

try {

    ZipOutputStream zip = new ZipOutputStream(new FileOutputStream("C:/archive.zip"));

    //GetImgURLs() is however you get your image URLs

    for(URL imgURL : GetImgURLs()) {
        is = imgURL.openStream();
        zip.putNextEntry(new ZipEntry(imgURL.getFile()));
        int length;

        byte[] b = new byte[2048];

        while((length = is.read(b)) > 0) {
            zip.write(b, 0, length);
        }
        zip.closeEntry();
        is.close();
    }
    zip.close();
}

Ref: ZipOutputStream Example

Answer 2

The url should return zip file. Else you have to take one by one and create a zip using your program