best freeware to crop PDF pages

To crop PDF pages, use PDF Scissors.
http://www.pdfscissors.com/

It is a Java program which can be run online as well as offline.

How to save everything displayed in cmd windows

To save everything in cmd windows as a txt file,

        dir > t.txt

You cannot see anything in the screen, but everything supposed to be displayed saved in t.txt file.
It calls "output redirection".
If you want to print out,
        dir > prn

We can utilize this skill for java with compiled program (e.g., double_data.class).
e.g.,  in cmd windows,
        java  double_data  >  t.txt

Java Applets in HTML5

Java Applets in HTML5

1. Creating the Sample Applet

Create Sample.jar from Sample.java, like so:
::] javac -version
javac 1.6.0_21

::] javac Sample.java

::] jar cvf Sample.jar *.class



2. Code to Add Sample Applet to HTML Page

OLD WAY: Java applet in HTML 4.01

<applet code="Sample" archive="Sample.jar" height="300" width="550">
  Applet failed to run.  No Java plug-in was found.
</applet>

NEW WAY: Java Applet in HTML5 (uses object tag)

<object type="application/x-java-applet" height="300" width="550">
  <param name="code" value="Sample" />
  <param name="archive" value="Sample.jar" />
  Applet failed to run.  No Java plug-in was found.
</object>



3. A Better Way

pack200 jar Compression

There is a way to GREATLY reduce the save of the downloaded jar file;
that way is to use pack200 ( pack200 and Compression ).

Creating the Compressed jar File and Sample.jar.pack.gz
::] pack200 -r Sample.jar

::] pack200 Sample.jar.pack.gz Sample.jar

Why Use pack200 and How to Use It in An Applet

NOTE: The command: pack200 -r Sample.jar,
repacks the Sample.jar file
(This produces a slightly smaller jar file. (deflated about 1%))

NOTE: The command: pack200 Sample.jar.pack.gz Sample.jar,
produces a compressed jar file named Sample.jar.pack.gz
(Size of Sample.jar.pack.gz is much smaller (deflated about 70% from original Sample.jar))

When the following line is added to the Java applet:
<param name="java_arguments" value="-Djnlp.packEnabled=true"/>
the Java plug-in will automatically download and try using the compressed jar file (Sample.jar.pack.gz).
If the browser is unable to use the compressed jar file, the uncompressed jar file (Sample.jar) will be downloaded.

Finally, the Best Way to Add A Java Applet to An HTML5 Document



4. BEST WAY: Java Applet in HTML5 (using pack200 jar compression)

<object type="application/x-java-applet" height="300" width="550">
  <param name="code" value="Sample" />
  <param name="archive" value="Sample.jar" />
  <param name="java_arguments" value="-Djnlp.packEnabled=true"/>
  Applet failed to run.  No Java plug-in was found.
</object>


https://eyeasme.com/Shayne/HTML5_APPLETS/

[Java] make a list reading a txt file

// Java
// make a list reading a txt file

import java.io.*;
import java.util.*;

public class list_from_file_2 {

    public static void main(String[] args) throws IOException {
        
        Scanner scan = new Scanner(new File("list.txt"));
        List<String> doubles = new ArrayList<String>();
        
        while(scan.hasNext()){
            doubles.add(scan.next());
        }
        
        Collections.sort(doubles);
        for (String d : doubles) System.out.println(d);
        
        
    }
}
------------------------------------------------------------------------

// Java
// make a list reading a txt file

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

public class list_from_file {

    public static void main(String[] args) throws IOException {

        BufferedReader in = null;
        FileReader fr = null;
        List<String> list = new ArrayList<String>();   // String type data read from txt file

        try {
            fr = new FileReader("list.txt");
            in = new BufferedReader(fr);
            String str;
            while ((str = in.readLine()) != null) {
                list.add(str); // or list.setListData(str); // for jList
                //list.add(Double.parseDouble(str));  // if read data is double number
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            in.close();
            fr.close();
        }

        for (String d : list) System.out.println(d);
    }

}

[Java] array, for-each

// Java
// Array

class array
{
    public static void main(String[] args)
    {
        int[][] arr = new int[3][4];   // 2nd-order array
        for(int i=0; i<arr.length; i++)
            for(int j=0; j<arr[i].length; j++)
                arr[i][j] = i + j;
                
        for(int i=0; i<arr.length; i++)
        {
            for(int j=0; j<arr[i].length; j++)
                System.out.print(arr[i][j] + " ");
            System.out.println();
        }
        
        int [] ar = {1, 3, 5};  // 1st-order array => int[] ar = new int[] {1,3,5};
        for (int e : ar)    // for, each
            System.out.print(e + " ");
            
    }
}

[Java] file I/O

// Java
// text file read (line by line)
import java.io.*;
import java.util.*;   // to use "ArrayList"

public class file_IO_4 {
 
     public static void main(String[] args) {
           
            // File Open
            File oFile = new File("./animal/livestock.txt");
           
            // Creat object for File Reader
            FileReader frd = null;
            BufferedReader brd = null;
           
            // define "ArrayList" for saving line-by-line content of file 
            ArrayList<String> lineList = new ArrayList<String>();
 
            // variables for saving line by line
            String rLine = null;
            int lineNum = 0;
            boolean hasMore = true;
           
            try {
                  frd = new FileReader(oFile);
                  brd = new BufferedReader(frd);  
                                                         
                  System.out.println();
                  while (hasMore) {
                     if((rLine = brd.readLine())!= null){
                         System.out.println(rLine);
                               
                         // Add read line to ArrayList
                         lineList.add(rLine);
                         lineNum++;
                         hasMore = true;
                      } else
                         hasMore = false;                       
            }
                 
                  frd.close();
                  brd.close();
            } catch (IOException e) {
                  e.printStackTrace();
            }           
           
            // Print size of Array List 
            System.out.println();
            System.out.println(lineList.size());
            System.out.println(lineList);
            System.out.println();
           
            // Print line by line (for loop)
            lineNum = lineList.size();
            for(int i=0; i<lineNum; i++) {
             System.out.println( i +": "+lineList.get(i));
            }           
     }
}

---------------------------------------------------------------------

// Java
// file read and write

import java.io.*;   // to use file input/output
import java.util.*;  // to use Scanner (keyboard input)

class file_IO_2
{

    InputStreamReader isr = new InputStreamReader(System.in);
    BufferedWriter bw = null;
    BufferedReader br = null;
    
    Scanner scan = new Scanner (System.in);
    
    int menuNum;
    String input, output, filename = "sentences.txt";
    
    
    void p(Object ob) {
        System.out.print(ob);
    }
        
    
    public static void main(String[] args) throws Exception
    {
        file_IO_2  f2 = new file_IO_2();
        f2.menu();
    }
    
    
    void menu() throws Exception
    {
        p("\n");
        p("\t   1. Input sentences   \n");
        p("\t   2. Print sentences   \n");
        p("\t   3. Quit   \n");
        p("\n");
        p("\t   Select :  ");
        
        while(true) {
            if(scan.hasNextInt())  {
                menuNum = scan.nextInt();
                break;
            }  else  {
                p("Please enter number between 1 and 3   \n");
            }
            }
            
        switch(menuNum)  {
            case 1:
                input();
                break;
            case 2:
                output();
                break;
            case 3:
                break;
            default:
                p("Please enter number between 1 and 3   \n");
                menu();
        }
        
        isr.close();
        br.close();
        bw.close();
    }
    
    
    void input() throws Exception 
    {
        p("\nLet's start to input sentences   \n");
        p("If you want to stop, press \"Enter\" in an empty line   \n");
        
        bw = new BufferedWriter(new FileWriter(filename));
        br = new BufferedReader(isr);
        while(!(input = br.readLine()).equals(""))  {
            bw.write(input);
            bw.newLine();
        }
        
        p("File saved \n");
        
        bw.flush();
        menu();
    }
    
    void output() throws Exception
    {
        p("\nSentences in \"" + filename + "\" \n\n");
        br = new BufferedReader(new FileReader(filename));
        int lineCnt=0;
        while(true)  {
            lineCnt++;
            output = br.readLine();
            if (output == null) {
                break;
            }
            p(lineCnt + ". " + output + "\n");
        }
        menu();
    }
    
}

------------------------------------------------------------------------

// Java
// file read and write

// 1. input # of items
// 2. input item's name, price, location
// 3. write input data in a file "item.db"
// 4. read the file and print all items' name

import java.util.*;
import java.io.*;  // to use file input, also include "throws IOException" in main method declaration, or "throws Exception" to read file (object in the file)
import java.text.DecimalFormat;  // to use decimal format

class file_IO
{

 public static void main(String[] args) throws Exception
 {
        DecimalFormat df = new DecimalFormat ("#.##");
        
        String filename = "item.db";
        ObjectOutputStream out = new ObjectOutputStream(new FileOutputStream(filename));
        ObjectInputStream in = new ObjectInputStream(new FileInputStream(filename));
        
        // # of items
        System.out.println("total number of items");
        Scanner ni = new Scanner (System.in);    
        while(!ni.hasNextInt())
        {
            ni.next();  // if input is not integer value, ignore it.
            System.err.println("Input should be integer value");
        }
        int n = ni.nextInt();
        
        
        // keyboard input
        for (int nn=1; nn<=n; nn=nn+1)
        {
            System.out.println("Input name of item # " +nn);
            Scanner i1n = new Scanner (System.in);    
            String n1 = i1n.next();
        
            System.out.println("Input price of item # " +nn);
            Scanner i1p = new Scanner (System.in);    
            while(!i1p.hasNextDouble()) {
                i1p.next();  // if input is not integer value, ignore it.
                System.err.println("Input should be a number");  }
            double p1 = i1p.nextDouble();
            
            System.out.println("Input location of item # " +nn);
            Scanner i1l = new Scanner (System.in);    
            String l1 = i1l.next();

            Item i1 = new Item(n1, p1, l1);
            
            out.writeObject(i1);
        }
        out.close();
        
        System.out.println();
        
        
        Item read_object;
        while( (read_object = (Item) in.readObject()) != null)
        {
            System.out.println(read_object.getName());
        }
        in.close();
        
}
}
 
 
 class Item implements Serializable 
 {
    String name, location;
    Double price;
    
    public Item (String name, double price, String location)
    {
        this.name = name;
        this.price = price;
        this.location = location;
    }
    
    String getName()
    {
        return name;
    }
    
    double getPrice()
    {
        return price;
    }
    
    String getLocation()
    {
        return location;
    }
    
}

[Java] console output (println, print, printf)

\n  :  next line
\t  :  tab
\"  :  " (quotation mark)
\\  :  \ (backslash)

System.out.println("She said \"I love you.\" ");
     -->  She said "I love you."

System.out.print("I will");
System.out.print("get a job soon");
     -->  I will get a job soon


%d  :  Integer
%f  :  Real number
%e  :  Exponent
%c  :  Char
%s  :  String

System.out.printf("%d,  %f,  %e,  %c,  %s",  12, 3.44, 0.00223, 'S', "SHSJ");
     -->  12, 3.44, 2.23e-3,  S,  SHSJ

[Java] setText format (how to round number)

// Java
// how to round number


import java.text.DecimalFormat;

class round_number
{

 public static void main(String[] args)    // main method
 {
        
        DecimalFormat df = new DecimalFormat("#.##");
        
        double num = 3.141592;

        System.out.println(df.format(num));

 }
}

-----------------------------------------------------------------

in GUI (Netbeans),

import java.text.DecimalFormat;   // outside class

//inside method
DecimalFormat df = new DecimalFormat("#.##");
jLabel1.setText(df.format(num));

[Java] method with multiple instances (objects)

method_with_multiple_instances.java

// Java
// method with multiple instances (objects)

// works with NumberInput.java

class method_with_multiple_instances
{

 public static void main(String[] args)    // main method
 {
        NumberInput n1=new NumberInput();
        System.out.println("current value = " + n1.getNum());
        
        simpleMethod(n1);
        System.out.println("current value = " + n1.getNum());
}

    public static void simpleMethod(NumberInput calc1)
    {
        calc1.addNum(12);

    }
}

-------------------------------------------------------------------

NumberInput.java

// Java
// method with multiple instances (objects)

// works with method_with_multiple_instances.java

class NumberInput
{
    // instance (object) variable
    int result=0;
    
 public void addNum(int n1)     // method "addNum"
 {
 
        result = result + n1;
        
}

    public int getNum()
    {
        return result;
    }
}

[Java] method with reflection

// Java
// method with reflection


import java.util.*;

class method_with_reflection
{

// A java program must start with "main" method
 public static void main(String[] args)    // main method
 {
 
        System.out.println("first number for factorial?");
        Scanner scan1 = new Scanner (System.in);
        
        while(!scan1.hasNextDouble())
        {
            scan1.next();  // if input is not integer value, ignore it.
            System.err.println("Input should be number");
        }
        double n1=scan1.nextDouble(); 
        
        System.out.println("second number for factorial?");
        Scanner scan2 = new Scanner (System.in);
        
        while(!scan2.hasNextDouble())
        {
            scan2.next();  // if input is not integer value, ignore it.
            System.err.println("Input should be number");
        }
        double n2=scan2.nextDouble(); 

        if(n1==0 && n2==0) {
            bye();    // if weight was input 0, call method "bye"
            System.exit(0); }
                

        System.out.println();        
        System.out.println(n1 + " factorial = " + factorial(n1));  
        System.out.println(n2 + " factorial = " + factorial(n2)); 

}


 public static double factorial(double n)
 {
        if (n==1)
            return 1;
        else
            return n*factorial(n-1);
 }
 

 public static void bye()
 {
        System.out.println();        
        System.out.println("Good Bye");
 }
}

[Java] method with return values

// Java
// method with return values


import java.util.*;

class method_with_return
{

// A java program must start with "main" method
 public static void main(String[] args)    // main method
 {
 
        System.out.println("first number?");
        Scanner scan1 = new Scanner (System.in);
        
        while(!scan1.hasNextDouble())
        {
            scan1.next();  // if input is not integer value, ignore it.
            System.err.println("Input should be number");
        }
        double n1=scan1.nextDouble(); 
        
        System.out.println("second number?");
        Scanner scan2 = new Scanner (System.in);
        
        while(!scan2.hasNextDouble())
        {
            scan2.next();  // if input is not integer value, ignore it.
            System.err.println("Input should be number");
        }
        double n2=scan2.nextDouble(); 

        if(n1==0 && n2==0) {
            bye();    // if weight was input 0, call method "bye"
            System.exit(0); }
                
        
        System.out.println("What do you want?  (1) multiply, (2) divide");
        Scanner scan3 = new Scanner (System.in);
        
        while(!scan3.hasNextInt())
        {
            scan3.next();  // if input is not integer value, ignore it.
            System.err.println("Input should be 1 or 2");
        }
        int op=scan3.nextInt(); 


        if(op==1)
        {    System.out.println();        
            System.out.println(n1 + " * " + n2 + " = " + function1(n1, n2));  
        } else 
            {
                System.out.println();        
                System.out.println(n1 + " / " + n2 + " = " + function2(n1, n2));  
            }
}


 public static double function1(double n1, double n2)
 {
        return n1*n2;
 }
 
  public static double function2(double n1, double n2)
 {
        return n1/n2;
 }
 
 public static void bye()
 {
        System.out.println();        
        System.out.println("Good Bye");
 }
}