= Java =

== Regular expressions ==
{{{#!Java
/*
javac TesteRe.java 
java -cp . TesteRe 
*/
/*
gcj -C TesteRe.java  # compile with gcj, GNU compiler for Java
gij -cp . TesteRe # run with gij, GNU interpreter for Java

Linux executable
gcj --main=TesteRe -g -o TesteRe TesteRe.java
ldd TesteRe
./TesteRe
*/

import java.util.regex.Pattern;
import java.util.regex.Matcher;

public class TesteRe{

    public static void main(String args[]){ 
        String values[]={"aa12.txt","a123sss.txt","bs11bb.txt","123aaaa.sql","a12.txt","aaaa12","20ghj","6657"};
        Pattern a = Pattern.compile("^(\\D+)(\\d+)(\\D+)$");
        Pattern b = Pattern.compile("^(\\d+)(\\D+)$");
        Pattern c = Pattern.compile("^(\\D+)(\\d+)$");
        Pattern d = Pattern.compile("^(\\d+)$");

        for(String item:values){
            Matcher ma = a.matcher(item);
            Matcher mb = b.matcher(item);
            Matcher mc = c.matcher(item);
            Matcher md = d.matcher(item);

           if(ma.matches()){ 
               int val = Integer.parseInt(ma.group(2)) + 1;
               System.out.println(String.format("A: mv %s %s%d%s",item,ma.group(1),val,ma.group(3)  ) );
           }

           if(mb.matches()){ 
               int val = Integer.parseInt(mb.group(1)) + 1;
               System.out.println(String.format("B: mv %s %d%s",item, val , mb.group(2)  ) );
           }

           if(mc.matches()){ 
               int val = Integer.parseInt(mc.group(2)) + 1;
               System.out.println(String.format("C: mv %s %s%d",item,mc.group(1),val   ) );
           }

           if(md.matches()){ 
               int val = Integer.parseInt(md.group(1)) + 1;
               System.out.println(String.format("D: mv %s %d",item, val  ) );
           }

        }
    }
}

}}}

== Server/client ==
Server
{{{#!java
import java.net.ServerSocket;
import java.net.Socket;
import java.lang.Thread;
import java.util.Stack;

public class SocketServer{
    public static void main(String []args){
        ServerSocket ss = null; 
        int nrThreads= Runtime.getRuntime().availableProcessors() * 2; 
        System.out.println("Nr cores:" + nrThreads);
        ConnHandler[] c = new ConnHandler[nrThreads];
        for(int i=0;i<nrThreads;i++){
            c[i]=new ConnHandler();
            c[i].start();
        }
        
        try{ 
            ss = new ServerSocket(1234); 
            ss.setReuseAddress(true);
        }
        catch(Exception ex){    }
        long count=0;
        while(true){
          try{
            Socket s = ss.accept(); 
            s.setSoLinger(true,0);
            int idx = (int)count%nrThreads;
            c[ idx  ].addSocket(s);
            count++;
            
          }
          catch(Exception ex){
              System.out.println(ex.getMessage());
          }
        }
    }
}
}}}

ConnHandler
{{{#!java
import java.net.ServerSocket;
import java.net.Socket;
import java.lang.Thread;
import java.util.Stack;

public class ConnHandler extends Thread{
    private byte[] rx;
    private Stack stack;
    long tid;

    public ConnHandler(){
        this.rx= new byte[1024];
        this.stack = new Stack();
    }

    public void addSocket(Socket s){
        this.stack.push(s);
    }

    public void run(){
        this.tid = Thread.currentThread().getId();

        while(true){
            if( this.stack.empty() == false){
                Socket s = (Socket)this.stack.pop();
                try{
                    if( s.getInputStream().available() > 0 ){
                        int readedBytes = s.getInputStream().read( rx );
                         System.out.println("ThreadId:"+tid  + " ReadedBytes:"+ readedBytes + 
" StackSize:" + this.stack.size() );
                    }
                    s.close();
                }
                catch(Exception ex){
                } 
            }
            else{ try{ Thread.sleep(500); }catch(Exception ex){} }
        }
    }
}
}}}

Client (python)
{{{#!python
import threading
import time
import socket

class Client (threading.Thread):
    def __init__(self):
        threading.Thread.__init__(self) #required

    def run(self):
        for x in range(1,100):
            HOST = 'localhost'
            PORT = 1234
            s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
            print('connecting...')
            s.connect((HOST, PORT))
            print('sending config...')
            s.send('test\r\n')
            s.close()
            print('complete')

if __name__=='__main__':
    clients=[]
    for x in range(1,100):
        clients.append( Client() )
    for c in clients:
        c.start()
}}}


== JAVA_TOOL_OPTIONS ==
Since the command-line cannot always be accessed or modified, for example in embedded VMs or simply VMs launched deep within scripts, a JAVA_TOOL_OPTIONS variable is provided so that agents may be launched in these cases.

 * set JAVA_TOOL_OPTIONS=-Dfile.encoding=utf8
 * export JAVA_TOOL_OPTIONS=-Dfile.encoding=utf8

http://docs.oracle.com/javase/7/docs/platform/jvmti/jvmti.html#tooloptions

== Access private field via reflection ==
 * http://stackoverflow.com/questions/1555658/is-it-possible-in-java-to-access-private-fields-via-reflection
{{{#!highlight java
java.lang.refelct.Field f = ClassX.class.getDeclaredField("fieldx");
f.setAccessible(true);
FieldType ft = f.get(objectWithPrivateField);
}}}

== Generate Javadoc using command line ==
 * dir /s /b *.java > javafiles.txt
 * javadoc -encoding UTF-8 -d docs @javafiles.txt