Java Reference
In-Depth Information
Point[] p = new Point[100];
for (int i = 0; i < p.length; i++) {
p[i] = new Point();
p[i].move(i, p.length-1-i);
}
}
}
Inlining the method
move
of class
Point
in method
main
would transform the
for
loop to
the form:
for (int i = 0; i < p.length; i++) {
p[i] = new Point();
Point pi = p[i];
int j = p.length-1-i;
pi.x += i;
pi.y += j;
}
The loop might then be subject to further optimizations.
Such inlining cannot be done at compile time unless it can be guaranteed that
Test
and
Point
will always be recompiled together, so that whenever
Point
- and specifically its
move
method - changes, the code for
Test.main
will also be updated.
8.4.3.4. native Methods
A method that is
native
is implemented in platform-dependent code, typically written in an-
other programming language such as C. The body of a
native
method is given as a semicolon
only, indicating that the implementation is omitted, instead of a block.
For example, the class
RandomAccessFile
of the package
java.io
might declare the fol-
lowing
native
methods:
package java.io;
public class RandomAccessFile
implements DataOutput, DataInput {
. . .
public native void open(String name, boolean writeable)
throws IOException;
public native int readBytes(byte[] b, int off, int len)
throws IOException;
public native void writeBytes(byte[] b, int off, int len)
throws IOException;
public native long getFilePointer() throws IOException;
