в 17:43, 31 мая 2010

2010-05-31T17:43:48Z

Admin: 1 версия

2010-05-31T14:41:01Z

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== Object: finalize() ==



<source lang="java">

public class MainClass {
public static void main(String[] args) throws Exception {
Object f = new Object() {
public void finalize() {
System.out.println("Running finalize()");
}
};
Runtime.getRuntime().addShutdownHook(new Thread() {
public void run() {
System.out.println("Running Shutdown Hook");
}
});
f = null;
System.gc();
System.out.println("Calling System.exit()");
System.exit(0);
}
}

</source>



== Object: getClass() ==



<source lang="java">

/*
* Output:
x is object of type: Class1
y is object of type: Class2
y"s superclass is Class1
*
*/
class Class1 {
int a;
float b;
}
class Class2 extends Class1 {
double c;
}
public class MainClass {
public static void main(String args[]) {
Class1 x = new Class1();
Class2 y = new Class2();
Class clObj;
clObj = x.getClass(); // get Class reference
System.out.println("x is object of type: " + clObj.getName());
clObj = y.getClass(); // get Class reference
System.out.println("y is object of type: " + clObj.getName());
clObj = clObj.getSuperclass();
System.out.println("y"s superclass is " + clObj.getName());
}
}

</source>



== Object: getClass() (2) ==



<source lang="java">

/*
* Output:
Public Methods:
a1
a2
* */
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
public class MainClass {
public static void main(String args[]) {
try {
MyClass a = new MyClass();
Class c = a.getClass();
System.out.println("Public Methods:");
Method methods[] = c.getDeclaredMethods();
for (int i = 0; i < methods.length; i++) {
int modifiers = methods[i].getModifiers();
if (Modifier.isPublic(modifiers)) {
System.out.println(" " + methods[i].getName());
}
}
} catch (Exception e) {
System.out.println("Exception: " + e);
}
}
}
class MyClass {
public void a1() {
}
public void a2() {
}
protected void a3() {
}
private void a4() {
}
}

</source>



== Object: hashCode() ==



<source lang="java">

/*
About to hashCode 2 objects.
MainClass@cf2c80 --> 13577344
java.awt.Color[r=68,g=136,b=204] --> -12285748
*/
public class MainClass {
/** Some objects to hashCode() on */
protected static Object[] data = { new MainClass(), new java.awt.Color(0x44, 0x88, 0xcc) };
public static void main(String[] args) {
System.out.println("About to hashCode " + data.length + " objects.");
for (int i = 0; i < data.length; i++) {
System.out.println(data[i].toString() + " --> " + data[i].hashCode());
}
}
}

</source>



== Object: notifyAll() ==



<source lang="java">

/*
* Output:
Calling wait
Calling notifyAll
Done
Done

*/
class SyncFlag {
boolean flag;
synchronized void k1() {
if(flag == false) {
flag = true;
try {
System.out.println("Calling wait");
wait();
}
catch(Exception e) {
e.printStackTrace();
}
}
else {
flag = false;
System.out.println("Calling notifyAll");
notifyAll();
}
}
}
class MyThread extends Thread {
SyncFlag flag;
MyThread(SyncFlag k) {
this.flag = k;
}
public void run() {
flag.k1();
System.out.println("Done");
}
}
public class MainClass {
public static void main(String args[]) {
SyncFlag k = new SyncFlag();
new MyThread(k).start();
new MyThread(k).start();
}
}

</source>



== Object: toString() ==



<source lang="java">

/*
* Output:
* Point[123456789,2147483647]
* */
class Point {
int x, y;
Point(int x, int y) {
this.x = x;
this.y = y;
}
public String toString() {
return "Point[" + x + "," + y + "]";
}
}
public class MainClass {
public static void main(String args[]) {
Point p = new Point(123456789, 2147483647);
System.out.print(p);
}
}

</source>



== Object: wait(long timeout) ==



<source lang="java">

public class Main {
public static void main(String str[]) {
final Object monitor = new Object();
new Thread() {
public void run() {
try {
synchronized (monitor) {
System.out.println("10 seconds ...");
monitor.wait(10000);
System.out.println("Wait over");
}
} catch (Throwable t) {
t.printStackTrace();
}
}
}.start();
}
}

</source>

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в 17:43, 31 мая 2010

Admin: 1 версия