Java Reference
In-Depth Information
This program prints:
Build inner shell
Inspect
Disassemble
Finish: Attach lift, insert fusing, wrap.
CHALLENGE 28.3
To support the
setShowInterior()
method, suppose that you add
a
showInterior
Boolean attribute to the
ComponentIterator
class. What
changes would you have to make in the
CompositeIterator
class so that
next()
will return only leaf nodes if
showInterior
is
false
?
Thread-Safe Iterators
When it returns the next value in a collection to a client, an iterator also returns control of the
program. This opens the possibility that a client will take an action that will change the
collection over which you are iterating. Consider a program that can update a list in one
thread while another thread is iterating over the list:
package com.oozinoz.applications;
import java.util.*;
public class ShowConcurrentFor implements Runnable
{
private List list;
protected static List upMachineNames()
{
return new ArrayList
(
Arrays.asList
(
new String[]
{
"Mixer1201",
"ShellAssembler1301",
"StarPress1401",
"UnloadBuffer1501"
}
)
);
}
protected void go()
{
list = Collections.synchronizedList(
upMachineNames());
for (int i = 0; i < list.size(); i++)
{
if (i == 1)
{ // simulate wake-up
new Thread(this).start();
}
