getdata.java

Thinking in JAVA第四版源代码

//: io/GetData.java
// Getting different representations from a ByteBuffer
import java.nio.*;
import static net.mindview.util.Print.*;

public class GetData {
  private static final int BSIZE = 1024;
  public static void main(String[] args) {
    ByteBuffer bb = ByteBuffer.allocate(BSIZE);
    // Allocation automatically zeroes the ByteBuffer:
    int i = 0;
    while(i++ < bb.limit())
      if(bb.get() != 0)
        print("nonzero");
    print("i = " + i);
    bb.rewind();
    // Store and read a char array:
    bb.asCharBuffer().put("Howdy!");
    char c;
    while((c = bb.getChar()) != 0)
      printnb(c + " ");
    print();
    bb.rewind();
    // Store and read a short:
    bb.asShortBuffer().put((short)471142);
    print(bb.getShort());
    bb.rewind();
    // Store and read an int:
    bb.asIntBuffer().put(99471142);
    print(bb.getInt());
    bb.rewind();
    // Store and read a long:
    bb.asLongBuffer().put(99471142);
    print(bb.getLong());
    bb.rewind();
    // Store and read a float:
    bb.asFloatBuffer().put(99471142);
    print(bb.getFloat());
    bb.rewind();
    // Store and read a double:
    bb.asDoubleBuffer().put(99471142);
    print(bb.getDouble());
    bb.rewind();
  }
} /* Output:
i = 1025
H o w d y !
12390
99471142
99471142
9.9471144E7
9.9471142E7
*///:~