网站制作什么,网站服务器迁移步骤,哪家成都公司做网站,安阳网站建设哪家公司好-1不是流中写入的数据。read()方法返回的数据都是unsigned byte#xff0c;即是[0,255]。底层实现有很多#xff0c;比如socket IO和文件IO#xff0c;甚至你自己也可以实现。——————————————————————给两个类的代码给你看看#xff0c;理解一下这个东…-1不是流中写入的数据。read()方法返回的数据都是unsigned byte即是[0,255]。底层实现有很多比如socket IO和文件IO甚至你自己也可以实现。——————————————————————给两个类的代码给你看看理解一下这个东西/*** 能随时获取读取了多少字节数据的InputStream*/public class LengthAwareInputStream extends FilterInputStream {private volatile long length;private long maxReadSize;public LengthAwareInputStream(InputStream in) {this(in, Long.MAX_VALUE);}public LengthAwareInputStream(InputStream in, long maxReadSize) {super(in);this.maxReadSize maxReadSize;}Overridepublic int read() throws IOException {//读取长度超过最大值用于检查流量if (length 1 maxReadSize) {throw new IOException(exceeded max read size: maxReadSize);}int ret super.read();if (ret 0) {length;}return ret;}Overridepublic int read(byte[] b, int off, int len) throws IOException {//读取长度超过最大值用于检查流量if (length len maxReadSize) {throw new IOException(exceeded max read size: maxReadSize);}int ret super.read(b, off, len);if (ret 0) {length ret;}return ret;}public long getLength() {return length;}}/*** 读取数据达到特定长度之后自动终止(即返回-1)* Created by Weijun on 2017/2/23.*/public class LengthLimitedInputStream extends LengthAwareInputStream {private final long limitBytes;/*** param in* param limitBytes*/public LengthLimitedInputStream(InputStream in, long limitBytes) {super(in);this.limitBytes limitBytes;}Overridepublic int read() throws IOException {if (getLength() limitBytes) {return -1;}return super.read();}Overridepublic int read(byte[] b, int off, int len) throws IOException {len (int) Math.min(len, limitBytes - getLength());if (len 0) {return -1;}return super.read(b, off, len);}}你并不需要关注底层IO流如何实现return -1。实在想看去看JDK的实现是c写的。
