JAVA

2012年8月24日星期五

Therad.join

Therad.join : 主要會完成一個程式後再跳出.

public class RunnableTest{
/**
* @param args
*/
public static void main(String[] args) {
  // TODO Auto-generated method stub
  CRTest AAA = new CRTest("AAA");
  CRTest BBB = new CRTest("BBB");

  Thread t1 = new Thread(AAA);
  Thread t2 = new Thread(BBB);

  t1.start();
  try {
   t1.join();
  } catch (InterruptedException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }
  t2.start();
  try {
   t2.join();
  } catch (InterruptedException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }
  System.out.println("end main");
}
}

public class CRTest implements Runnable{
private String id;
public CRTest(String s){
  id = s;
}

public void run() {

  for(int i = 0; i < 4; i++){
   int time = (int)(1000*Math.random());
   try {
    Thread.sleep(time);
   } catch (InterruptedException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
   }
   for(int j = 0; j < 10000000; j++);
    System.out.println(id + " is runing... Time : " + time);
  }
}
}

=====================================
AAA is runing... Time : 376
AAA is runing... Time : 46
AAA is runing... Time : 414
AAA is runing... Time : 438
BBB is runing... Time : 158
BBB is runing... Time : 801
BBB is runing... Time : 373
BBB is runing... Time : 864
end main
=====================================

sleep + random

public class CRTest implements Runnable{
private String id;
public CRTest(String s){
  id = s;
}

public void run() {

  for(int i = 0; i < 4; i++){
   int time = (int)(1000*Math.random());
   try {
    Thread.sleep(time);
   } catch (InterruptedException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
   }
   for(int j = 0; j < 10000000; j++);
    System.out.println(id + " is runing... Time : " + time);
  }
}
}

public class RunnableTest{
/**
* @param args
*/
public static void main(String[] args) {
  // TODO Auto-generated method stub
  CRTest AAA = new CRTest("AAA");
  CRTest BBB = new CRTest("BBB");

  Thread t1 = new Thread(AAA);
  Thread t2 = new Thread(BBB);

  t1.start();
  t2.start();
}
}

=======================================
AAA is runing... Time : 313
BBB is runing... Time : 671
AAA is runing... Time : 539
AAA is runing... Time : 239
AAA is runing... Time : 173
BBB is runing... Time : 628
BBB is runing... Time : 25
BBB is runing... Time : 762
========================================

Thread & Runnable

Thread
public class ThreadTest{
/**
* @param args
*/
public static void main(String[] args) {
  // TODO Auto-generated method stub
  CTest AAA = new CTest("AAA");
  CTest BBB = new CTest("BBB");
  AAA.start();
  BBB.start();
}
}

public class CTest extends Thread{

private String id;
public CTest(String s){
  id = s;
}

public void run() {

  for(int i = 0; i < 4; i++){
   for(int j = 0; j < 10000000; j++);
    System.out.println(id + " is runing...");
  }
}
}
=================================================
AAA is runing...
BBB is runing...
AAA is runing...
BBB is runing...
AAA is runing...
BBB is runing...
AAA is runing...
BBB is runing...
=================================================

Runnable

public class RunnableTest{
/**
* @param args
*/
public static void main(String[] args) {
  // TODO Auto-generated method stub
  CRTest AAA = new CRTest("AAA");
  CRTest BBB = new CRTest("BBB");

  Thread t1 = new Thread(AAA);
  Thread t2 = new Thread(BBB);
  t1.start();
  t2.start();
}
}

public class CRTest implements Runnable{
private String id;
public CRTest(String s){
  id = s;
}

public void run() {

  for(int i = 0; i < 4; i++){
   for(int j = 0; j < 10000000; j++);
    System.out.println(id + " is runing...");
  }
}
}
===================================
AAA is runing...
BBB is runing...
AAA is runing...
BBB is runing...
AAA is runing...
BBB is runing...
AAA is runing...
BBB is runing...
====================================

2012年8月22日星期三

IO Writer & Read

package kao.chih.chien.test;
import java.io.FileWriter;
import java.io.IOException;
public class WriterTest {
static String WRITER_TEST_PATH = "C:\\Test.txt";

/**
* @param args
*/
public static void main(String[] args) {
  // TODO Auto-generated method stub

   try {
    FileWriter fw = new FileWriter(WRITER_TEST_PATH,true);
    fw.write("\tHello");
    fw.close();
   } catch (IOException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
   }

}
}

package kao.chih.chien.test;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
public class ReadTest {
static String READ_TEST_PATH = "C:\\Test.txt";
static char data[] = new char[1024];
/**
* @param args
*/
public static void main(String[] args) {
  // TODO Auto-generated method stub
  try {
   FileReader fr = new FileReader(READ_TEST_PATH);
   int num = fr.read(data);
   String s = new String(data, 0, num);
   System.out.println(s);
  } catch (FileNotFoundException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  } catch (IOException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }
}
}

2012年8月8日星期三

JAVA CLASS 基本架構 & 建立新的物件

建立class :
A. 建一個class需要 1. 變數 2.建構子 3.method方法.
B. class中不能在有其他class.

class 類別名稱
{
資料型態 field 名稱 ;

建構子 ()
{
...............
}

傳回值的資料型態 method 名稱 ( 引數 1, ............ )
{

}

}

建立新的物件 :
A. 宣告指向 "類別"的變數.
B. 利用new關鍵字,建立新的物件,並指派給所建立的變數.

Hello A;
A = new Hello();

也可以縮成一行

Hello A = new Hello();