Question

如何把byte转换成inputstream

Answer 1

1、将File、FileInputStream 转换为byte数组：
File file = new File("file.txt");
InputStream input = new FileInputStream(file);
byte[] byt = new byte[input.available()];
input.read(byt);

2、将byte数组转换为InputStream：
byte[] byt = new byte[1024];
InputStream input = new ByteArrayInputStream(byt);

3、将byte数组转换为File：
File file = new File('');
OutputStream output = new FileOutputStream(file);
BufferedOutputStream bufferedOutput = new BufferedOutputStream(output);
bufferedOutput.write(byt);

Answer 2

代码如下
FileInputStream instream = new FileInputStream(filename);
byte[] k=new byte[1024*1024*20];
int bloblength=instream.read(k);
byte[] blobparam=new byte[bloblength];
instream = new FileInputStream(filename);
instream.read(blobparam,0,blobparam.length);