InputStream小技巧
<ul>
<li>InputStream读流不用while循环实现之fileInputStream.available()</li>
</ul>
<pre><code>fileInputStream.available()
返回可以读取的剩余字节数的估计值
代码示例:
String url="F:\\img\\cat.jpg";
File file=new File(url);
FileInputStream fileInputStream=new FileInputStream(file);
//读取可用的字节大小,填充
byte[] arr=new byte[fileInputStream.available()];
fileInputStream.read(arr);
FileOutputStream fileOutputStream=new FileOutputStream(new File("F:\\img\\cat33.jpg"));
fileOutputStream.write(arr);
fileOutputStream.flush();
fileInputStream.c
System.out.println(Base64.getEncoder().encodeToString(arr));
</code></pre>