Clear command line console and display bold size of string in Java Command Line Application

To clean console of your command line application,use following code :

  /**  
   * This method clear the current screen  
   *   
   *   
   */  
   public static void clearScreen() {  
    System.out.print("\033[H\033[2J");  
    System.out.flush();  
   }  

To make bold size of any string,

  public void boldSizeOfString()  
   {  
       String strNormalSize = "\033[0;0m";  
       String strBoldSize = "\033[0;1m";  
         System.out.println (strNormalSize + "My Name is Anthony Gonsalves" + strBoldSize);  
   }  

How to create jar and run from command line

In order to create runnable jar,You need to do following steps in Eclipse:

1) Right Click on your project.Select Export Option and then Select Runnable Jar File Option.

2) After Clicking Next, select the main class of your project in Launch configuration and Specify the path and name of jar file in Export destination.

3) Click Finish.

To Run Jar File,Follow the steps mentioned below:

1) Make Sure java path is set in Environment variable.
2) Open command Line
3) Go to path where Jar is generated. in this case : cd f:/aapps/
4) Run java -jar Test.jar

Detecting key events in Console application Using JLine

JLine is nothing but a java library for handling console inputs.It can detects various keys which System class can not detect.

For ex:you can not detect ESC key or ENTER key pressed in java.

JLine ConsoleReader object can detects special key using its readVirtualKey() function.
For more information about JLine.

You can download the jar from http://www.java2s.com/Code/Jar/j/Downloadjlinejar.htm.

For maven dependency refer this http://mvnrepository.com/artifact/jline/jline

Using Jline you can ROTATE the list using UP and DOWN arrow key.
For ex: If you want to rotate list of country names. using UP and DOWN arrow key

public String ArrowKeysForSelctingCountryName() throws IOException {  
           List<String> listCountry = new ArrayList<String>();  
           listCountry.add("India");  
           listCountry.add("Australia");  
           listCountry.add("UK");  
           int i = 0;  
           boolean isValueSelected = false;  
           String strCountryName = null;  
           ListIterator<String> itr = listCountry.listIterator();  
           int key;  
           ConsoleReader consoleReader = new ConsoleReader();  
           while ((key = consoleReader.readVirtualKey()) != 10) {  
                // to clear previous list name ,you can customise it according to you.  
                for (int clear = 0; clear < 100; clear++) {  
                     consoleReader.delete();  
                }  
                switch (key) {  
                // UP arrow key  
                case 65539:  
                     isValueSelected = true;  
                     for (; i < listCountry.size(); i++) {  
                          if (itr.hasNext()) {  
                               strCountryName = itr.next();  
                               consoleReader.putString(strCountryName);  
                               Collections.rotate(listCountry, i);  
                               consoleReader.moveCursor(-(strCountryName.length()));  
                               break;  
                          } else {  
                               while (itr.hasPrevious()) {  
                                    itr.previous();  
                               }  
                          }  
                     }  
                     if (i == listCountry.size() - 1) {  
                          while (itr.hasPrevious()) {  
                               itr.previous();  
                          }  
                     }  
                     break;  
                // Down Arrow Key  
                case 65540:  
                     isValueSelected = true;  
                     for (; i < listCountry.size(); i++) {  
                          if (itr.hasNext()) {  
                               strCountryName = itr.next();  
                               consoleReader.putString(strCountryName);  
                               Collections.rotate(listCountry, i);  
                               consoleReader.moveCursor(-(strCountryName.length()));  
                               break;  
                          } else {  
                               while (itr.hasPrevious()) {  
                                    itr.previous();  
                               }  
                          }  
                     }  
                     if (i == listCountry.size() - 1) {  
                          while (itr.hasPrevious()) {  
                               itr.previous();  
                          }  
                     }  
                     break;  
                }  
           }  
           if (key == 10 && strCountryName.length() > 0 && isValueSelected == true) {  
                return strCountryName;  
           }  
           return strCountryName;  
      }  

You can also implement AUTO-COMPLETE functionality using TAB key.
Here is the sample code : to implement auto completion of students names.

 public static void AutoCompleteSelectingStudentsName() throws IOException {  
         List<String> lStudentsName = new ArrayList<String>();  
         lStudentsName.add("Ramesh");  
         lStudentsName.add("John");  
         lStudentsName.add("Bob");  
         // convert into string array  
         String[] arrStudentsNames = lStudentsName.toArray(new String[lStudentsName.size()]);  
         ConsoleReader consoleReader= new ConsoleReader();  
         consoleReader.addCompletor(new SimpleCompletor(arrStudentsNames));  
        }  

Error :Arc dependent binaries in noarch package (CentOS 6.5)

This error mostly occurs when you try to create RPM and if binary files are present in project,then It gives this error.
This error most likely to occur in Linux distributions like CentOS,Ubuntu,OpenSuse.

In order to avoid this error,you should to add following line in .spec file which gets generated whenever you create rpm.


   %define _binaries_in_noarch_packages_terminate_build   0

To add this line in .spec file of your build,mention this declaration in pom.xml.