问题描述
public class App {
public static void readSome(InputStream in) throws IOException {
ByteArrayInputStream is = new ByteArrayInputStream(in.readAllBytes());
is.read(); // variable number of non blocking reads
is.read();
is.read();
in = is; // this does nothing
}
public static void main(String[] args) throws IOException {
ByteArrayInputStream a = new ByteArrayInputStream(new byte[]{1,2,3,4,5,6});
App.readSome(a);
//something
App.readSome(a); // should read 4,6
}
}
是否可以更改readSome方法中的代码，以使main能够读取所有值，而readSome完成非阻塞读取？
解决方法
您的代码尝试两次使用ByteArrayInputStream-这是不可能的。就是这样。
public class App {
public static void readSome(InputStream source) throws IOException {
byte[] bytes = source.readAllBytes(); // Reads (consumes) all your bytes from the source
ByteArrayInputStream is = new ByteArrayInputStream(bytes);
is.read(); // variable number of non blocking reads
is.read();
is.read();
}
public static void main(String[] args) throws IOException {
ByteArrayInputStream source = new ByteArrayInputStream(new byte[] { 1,2,3,4,5,6 });
// source full
App.readSome(source);
// source fully consumed - so source is empty now
App.readSome(source); // cannot consume 4,6 - because source was already consumed.
}
}