java中Scanner的hasNext()的疑问

请问下面代码有什么区别，该如何输入才能使第一段代码不满足条件而跳出循环？

Scanner s = new Scanner(System.in);
while(s.hasNext())
{
System.out.println(s.next());
}

Scanner s = new Scanner(System.in);
while(true)
{
System.out.println(s.next());
}

第一个问题，两段代码的区别在于阻塞的位置不同，加上一行输出代码就可以很明显地看到差别。
import java.util.Scanner;

public class Test {
public static void main(String[] args) {
Scanner s = new Scanner(System.in);
while(s.hasNext())
{
System.out.print("You inputted: ");
System.out.println(s.next());
}
}
}

hasNext()方法会阻塞，不代表next()方法就不会阻塞,我们看源码。
/**
* Returns true if this scanner has another token in its input.
* This method may block while waiting for input to scan.
* The scanner does not advance past any input.
*
* @return true if and only if this scanner has another token
* @throws IllegalStateException if this scanner is closed
* @see java.util.Iterator
*/
public boolean hasNext() {
ensureOpen();
saveState();
while (!sourceClosed) {
if (hasTokenInBuffer())
return revertState(true);
readInput();
}
boolean result = hasTokenInBuffer();
return revertState(result);
}

/**
* Finds and returns the next complete token from this scanner.
* A complete token is preceded and followed by input that matches
* the delimiter pattern. This method may block while waiting for input
* to scan, even if a previous invocation of {@link #hasNext} returned
* <code>true</code>.
*
* @return the next token
* @throws NoSuchElementException if no more tokens are available
* @throws IllegalStateException if this scanner is closed
* @see java.util.Iterator
*/
public String next() {
ensureOpen();
clearCache
while (true) {
String token = getCompleteTokenInBuffer(null);
if (token != null) {
matchValid = true;
skipped = false;
return token;
}
if (needInput)
readInput();
else
throwFor();
}
}

第二个问题，想要结束循环，在Windows环境下，需要输入Ctrl+Z；而在Unix环境下，需要输入Ctrl+D（在myeclipse编译器中也是如此操作）。注意，这是输入，而不是对控制台进行操作。这相当于向控制台输入一个字符，这个字符代表EOF，此时hasNext()方法返回false，循环结束。