来自 OutputStream 的 ByteArrayOutputStream

Question

How to create OutputStream from ByteArrayOutputStream in Java

Answer 1

Following runs without error:

ByteArrayOutputStream stream = new ByteArrayOutputStream();
OutputStream outStream = stream;

If you see the docs for ByteArrayOutputStream you will find that it extends OutputStream.

Answer 2

ByteArrayOutputStream is a subclass of OutputStream .

ByteArrayOutputStream bos = ...;
OutputStream os = bos;

Answer 3

A ByteArrayOutputStream is an OutputStream . Ie you can just assign it like this:

ByteArrayOutputStream baos = new ByteArrayOutputStream();
OutputStream out = baos;

Answer 4

You can create a helper method like follows:

public OutputStream convert(ByteArrayOutputStream arrayOutputStreamParam){
        return arrayOutputStreamParam;
    }