Reading and saving UTF8 text file in Java

To read and save text file in Java, we need to add the "UTF-8" parameter in the Stream Reader.


File file = new File("1.txt");
BufferedReader reader = null;
try {
   reader = new BufferedReader(new InputStreamReader(new FileInputStream(file), "UTF-8"));
   String text = reader.readLine();
   String s1="\u6df1\u6c34\u57d7";
   String s2="深水埗";

   OutputStreamWriter out = new OutputStreamWriter(new FileOutputStream("2.txt"),"UTF-8");
   out.write(text+s1+s2);
   out.flush();
   out.close();

} catch (Exception e) {
   e.printStackTrace();
}


Capture standard output (stdout) in console command running at VBS

We can use WScript.Shell.Exec( ) and WScript.Shell.StdOut.ReadLine( ) to perform the task:


Set objShell = WScript.CreateObject("WScript.Shell")
Set objExecObject = objShell.Exec("cmd /c dir")
strText=""
Do While Not objExecObject.StdOut.AtEndOfStream
strText = strText & objExecObject.StdOut.ReadLine() & chr(13)
Loop
Wscript.Echo strText


Using X-Forward-For Header

Say if you have a web server on top of your application server, you can use "x-Forward-For" HTTP header in the application server to get the real IP of the client.

Note: Remote host only returns the IP of the web server instead.

Analyze JVM memory heap

To analyze how a Java web application is performed in terms of its memory usage, one can use Eclipse Memory Analyzer to do it.

Ref: Eclipse MAT

InetAddress.getByName( ) cached result

java.net.InetAddress.getByName( ) will cached the result, even when the host name IP is changed. To fix this, issue the following option to Java VM:

-Dsun.net.inetaddr.ttl=0

It sets the timeout of the DNS cache to zero.

Using netsh for IP config import/export

2 lines only:

netsh -c interface dump > filename

netsh -f filename

Ref: http://www.alibutt.com/?p=250

Some more about netsh to read at http://www.builderau.com.au/program/windows/print.htm?TYPE=story&AT=339272916-339024644t-320000994c

What is COPM?

COPM = Computer Operation Procedures Manual

How to check physical memory

1. winmsd.exe

2. pstat.exe (from resource kit)

3. memory.exe (http://www.savilltech.com/download/memory.zip)

From windowsitpro.com

Enable Java assertion

Just a soft reminder in case I want to use Java assertion. Given a class Cls:

> java -ea:Cls Cls

The comment will execute Cls which assertion enabled.

Remove system folder in windows explorer

Some program will create a system folder which could be viewed in your windows explorer. Sometimes when uninstalling the program, they cannot remove the system folder for you. To remove it, find those system folder are in:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows
\CurrentVersion\Explorer\MyComputer\NameSpace\

References are from technospot