Printing Java Call Stack

The following function could be use to print current java call stack.

Arrays.toString(new Throwable().getStackTrace()).replace(',', '\n')

Java reference type

以下連結針對Java soft reference及weak reference有很棒的解說

http://blog.centuryminds.com/2007/11/weak-and-soft-references-in-java/

Android 1.5 source code build error in Ubuntu 9.04

Issue:
make: *** [out/host/linux-x86/obj/EXECUTABLES/emulator_intermediates/sockets.o] Error 1

Solution:
Modify "external/qemu/Makefile.android"
Original:
# this is needed to build the emulator on 64-bit Linux systems
ifeq ($(HOST_OS)-$(HOST_ARCH),linux-x86)
MY_CFLAGS += -Wa,--32
endif

Modified:
# this is needed to build the emulator on 64-bit Linux systems
ifeq ($(HOST_OS)-$(HOST_ARCH),linux-x86)
MY_CFLAGS += -Wa,--32 -D_GNU_SOURCE
endif

Install/Update JDK on Linux

• sh jdk-6u7-linux-i586-rpm.bin

• alternatives --install /usr/java/jdk1.6.0_07/bin/java java /usr/java/latest/bin/java 2

• alternatives --config java

OOP .........Oops

物件導向程式設計(Object-Oriented Programming, OOP), 這真是個電腦語言界的偉大發明.
利用物件(Object)之間的互動關係來設計程式, 的確能讓程式有更加的彈性.
但是...對一個半調子的OOP程式員來說, 後面要加個"S"比較貼切.
最近很認真的在寫論文的模擬實驗, 更深刻的體會到OOP的博大精深.
對讀完大學加上研究所的資工系學生來說, 應該沒幾個人能寫出個像樣的物件導向程式.
再加上我又三八想寫個程窗的介面, 這根本是自找麻煩嘛!
不過說真的在寫模擬的過程中我也學到了不少東西.
最重要的就是了解如何去"設計 (Designing)"一個程式, 而不是"寫 (Coding)"一個程式.
說到這裡又不禁為台灣的資工系學生感到汗顏, 業界是很危險滴...快回你的火星吧!
唉~當初如果用程序式的方法硬幹...我該早畢業了吧XD

Eclipse for Everything

Eclipse真是個神奇的東西, 幾乎對所有程式語言都有plug-in

目前用它來寫java, c/c++(CDT + MinGW)及LaTeX(TeXlipse)

還有sublipse可以做version control

想當初癡肥的Visual Studio快把我搞瘋了

如今用了它以後頭腦就靈光了很多，每次考試都考一百分

我想在不久的將來所有的程式設計師電腦中只要有這一套IDE就夠了

Notes about Eclipse for Windows Programming

Setup Eclipse with CDT + MinGW for Windows Programming.

• Step1: install eclipse.

• Step2: install MinGW with win32api.

• Step3: install MinGW's gdb.

• Step4: run eclipse, install CDT by "Help->Software Updates->Find and Install".

• Step5: In general, you could build and debug regular c/c++ source file and win32 program. If you could not it, you have to do a little configure to enable it.

• Step6: open "Project->Properties", in "C/C++ build", click "Manage Configurations". New a new configuration named "Win32". In "C/C++ build->Settings", click "MinGW C++ Linker->Miscellaneous". Add a linker flag "-mwindows" and click apply.

• Step7: Try to build a win32 program again.

How can I create two classes that both know about each other?

Use a forward declaration.

Sometimes you must create two classes that use each other. This is called a circular dependency. For example:

class Fred {
public:
Barney* foo(); // Error: Unknown symbol 'Barney'
};

class Barney {
public:
Fred* bar();
};

The Fred class has a member function that returns a Barney*, and the Barney class has a member function that returns a Fred. You may inform the compiler about the existence of a class or structure by using a "forward declaration":

class Barney;

This line must appear before the declaration of class Fred. It simply informs the compiler that the name Barney is a class, and further it is a promise to the compiler that you will eventually supply a complete definition of that class.

Random Number

產生1到10之間的亂數

int main(void)
{
srand((unsigned)time(0));
int random_integer;
for(int i = 0;i < 20;i++)
{
random_integer = rand()%10;
cout << random_integer << endl;
}
}


How to Output Debug Message in Visual C++ Debug Mode's Output Area

DbgMessage.h
#ifndef _DBGMESSAGE_H_
#define _DBGMESSAGE_H_

void __cdecl DbgPrintf(LPCTSTR format, ...);

#endif /*_DBGMESSAGE_H_*/

#ifndef DBG_MAX_BUFFER_SIZE

#define DBG_MAX_BUFFER_SIZE 256

#endif /*_DBG_MAX_BUFFER_SIZE_*/

DbgMessage.cpp
#include "stdafx.h"

void __cdecl DbgPrintf(LPCTSTR format, ...)
{
static TCHAR DbgMsg[DBG_MAX_BUFFER_SIZE];
size_t len;
TCHAR *p = DbgMsg;
va_list args;

va_start(args, format);
StringCchVPrintf(p, sizeof(DbgMsg) - 1, format, args);
StringCchLength(DbgMsg, sizeof(DbgMsg) - 1, &len);
p += len;
va_end(args);

*p++ = '\r';
*p++ = '\n';
*p = '\0';

OutputDebugString(DbgMsg);
}


Usage:
int a = 101;
DbgPrintf(TEXT("hello %d"), a);

Programming Notes

An abstract class is one whose main purpose is to define a common interface for its subclasses.

An mixin class is a class that's intended to provide an optional interface to other classes. It's similar to an abstract class in that it's not intended to be instantiated.

Random Number Generation

在做模擬實驗時最重要的就如何去產生一組符合應用要求的random data set, 這個由Steve Park及Dave Geyer在98年所釋出的Multi-stream random number generation library, 可以產生許多常用到的random number, 其中包含...

Discrete Distributions:

1. Bernoulli
2. Binomial
3. Equilikely
4. Geometric
5. Pascal
6. Poisson

Continuous Distributions:

1. Uniform
2. Exponential
3. Erlang
4. Normal
5. Lognormal
6. Chisquare
7. Student

Latex with Chinese

0.安裝MikTex

1.安裝CJK套件

2.選擇字型(c:\texmf\tex\latex\CJK\Bg5\)

3.加入以下package
\usepackage{CJK}

4.使用以下指令加入中文
\begin{CJK}{Bg5}{bsmi}
\end{CJK}

Adding Console I/O to a Win32 GUI App

One of the common misconceptions surrounding Win32 programming is that you must decide early in the design process whether your application will be a console or GUI application. In reality, console applications can create windows and have a message loop just like a GUI application (see "Adding Graphics to Console Applications" by Michael Covington, Visual Developer, June/July 1997). Alternatively, graphical applications can create and use a console. Although Win32 provides functions for communicating with a console, they are a little clumsy to use and require parameters that are unnecessary for simple text I/O. This article shows how to use standard C/C++ I/O with consoles, and how to work around specific problems in the Visual C++ I/O library.

http://dslweb.nwnexus.com/~ast/dload/guicon.htm