java读取输入流

java读取输入流两种

    private static byte[] readStream(InputStream in){
        if(in==null){
            return null;
        }

        byte[] buffer = null;

        try {

            int availableLength = 0;
            while(availableLength==0){
                availableLength = in.available();//可获取的字节流长度

                if(availableLength==0&&in.read()==-1){//防止读取流返回为空造成死循环
                    break;
                }
            }

            buffer = new byte[availableLength];

            int readCount = 0;
            while(readCount<availableLength){
                readCount += in.read(buffer, readCount, availableLength-readCount);
            }

        } catch (IOException e) {
            e.printStackTrace();
        } finally{
            if(in!=null){
                try {
                    in.close();
                    in = null;
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }

        }

        return buffer;
    }

    public static byte[] readStream1(InputStream in) {

        byte[] b = null;
        ByteArrayOutputStream outSteam = null;
        try {
            byte[] buffer = new byte[1024 * 4];
            outSteam = new ByteArrayOutputStream();

            int len = -1;
            while ((len = in.read(buffer)) != -1) {
                outSteam.write(buffer, 0, len);
            }

            b = outSteam.toByteArray();
        } catch (IOException e) {
            e.printStackTrace();
        } finally{
            try {
                if(outSteam!=null){
                    outSteam.close();
                    outSteam = null;
                }
                if(in!=null){
                    in.close();
                    in = null;
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return b;
    }