LinkedHashMapDemo Java program

import java.util.*;
import java.util.Map.Entry;

public class LinkedHashMapDemo {

public static void main (String args[]){

LinkedHashMap lhm = new LinkedHashMap();

lhm.put("kapil", new Double(100.5) );
lhm.put("gaurav", new Double(200.6));
lhm.put("any", new Double(10.5));

Set> ss = lhm.entrySet();
Iterator> i =ss.iterator();

while(i.hasNext()){
Entry m = (Entry) i.next();
System.out.println("Here is key >> "+ m.getKey() );
System.out.println("Here is value >>"+ m.getValue());

}
System.out.println();
     
      double balance = ((Double)lhm.get("kapil")).doubleValue();
      lhm.put("kapil", new Double(balance + 1000));
      System.out.println("kapil new balance: " +
      lhm.get("kapil"));

}

}

Java program for Convert CSV into excel file

import java.io.DataInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;

import org.apache.log4j.Logger;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

public class CsvToXsl {
   
    private static DataInputStream myInput;
    private static XSSFWorkbook hwb;
    private static Logger log = Logger.getLogger(
    ResultGenerator.class.getName());

    @SuppressWarnings("deprecation")
public static void readCsvToXsl(String fullPath) throws IOException{
        File f = new File(fullPath +".csv");
        File f1 = new File(fullPath +".xlsx");
        if(f.exists() && !f1.exists()){
        try {
        log.info("Inside method readCsvToXsl for Generation");
        {
           
            ArrayList> arList=null;
            ArrayList al=null;
            String thisLine;
             FileInputStream fis = new FileInputStream(fullPath +".csv");
            myInput = new DataInputStream(fis);
            arList = new ArrayList>();
            while ((thisLine = myInput.readLine()) != null)
            {
             al = new ArrayList();
             String strar[] = thisLine.split(",");
             for(int j=0;j             {
             al.add(strar[j]);
             }
             arList.add(al);
            }

            try
            {
            hwb = new XSSFWorkbook ();
             XSSFSheet sheet = hwb.createSheet("new sheet");
              for(int k=0;k              {
               ArrayList ardata = (ArrayList)arList.get(k);
               Row row = sheet.createRow((short) 0+k);
               for(int p=0;p               {
                Cell cell = row.createCell((short) p);
                String data = ardata.get(p).toString();
                if(data.startsWith("=")){
                 cell.setCellType(Cell.CELL_TYPE_STRING);
                 data=data.replaceAll("\"", "");
                 data=data.replaceAll("=", "");
                 cell.setCellValue(data);
                }else if(data.startsWith("\"")){
                    data=data.replaceAll("\"", "");
                    cell.setCellType(Cell.CELL_TYPE_STRING);
                    cell.setCellValue(data);
                }else{
                    data=data.replaceAll("\"", "");
                    cell.setCellType(Cell.CELL_TYPE_NUMERIC);
                    cell.setCellValue(data);
                }
               }
              }
             FileOutputStream fileOut = new FileOutputStream(fullPath+".xlsx");
             hwb.write(fileOut);
             fileOut.close();
             log.info("Your excel file has been generated");
            } catch ( Exception ex ) {
                 ex.printStackTrace();
            }
            }
        }
       
        catch (IOException e) {
            e.printStackTrace();
            log.info("unbale to find csv file at path");
        }
      }
    }

}

Java program which show directory and file size

import java.io.File;
import java.util.Iterator;
import java.util.Vector;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JSplitPane;
import javax.swing.JTextArea;
import javax.swing.JTree;
import javax.swing.event.TreeModelEvent;
import javax.swing.event.TreeModelListener;
import javax.swing.event.TreeSelectionEvent;
import javax.swing.event.TreeSelectionListener;
import javax.swing.tree.TreeModel;
import javax.swing.tree.TreePath;

public class FileTreeFrame extends JFrame {

  /**
*
*/
private static final long serialVersionUID = 1L;
  private JTree fileTree;
  private FileSystemModel fileSystemModel;
  private JTextArea fileDetailsTextArea = new JTextArea();

  public FileTreeFrame(String directory) {
    super("JTree FileSystem Viewer - Impetus.com");
    fileDetailsTextArea.setEditable(false);
    fileSystemModel = new FileSystemModel(new File(directory));
    fileTree = new JTree(fileSystemModel);
    fileTree.setEditable(true);
    fileTree.addTreeSelectionListener(new TreeSelectionListener() {
      public void valueChanged(TreeSelectionEvent event) {
        File file = (File) fileTree.getLastSelectedPathComponent();
        fileDetailsTextArea.setText(getFileDetails(file));
      }
    });
    JSplitPane splitPane = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT, true, new JScrollPane(
        fileTree), new JScrollPane(fileDetailsTextArea));
    getContentPane().add(splitPane);
    setDefaultCloseOperation(EXIT_ON_CLOSE);
    setSize(640, 480);
    setVisible(true);
  }

  private String getFileDetails(File file) {
    if (file == null)
      return "";
    StringBuffer buffer = new StringBuffer();
    buffer.append("Name: " + file.getName() + "\n");
    buffer.append("Path: " + file.getPath() + "\n");
    buffer.append("Size: " + file.length() + "\n");
    return buffer.toString();
  }

  public static void main(String args[]) {
    new FileTreeFrame("d:\\");
  }
}

class FileSystemModel implements TreeModel {
  private File root;

  private Vector listeners = new Vector();

  public FileSystemModel(File rootDirectory) {
    root = rootDirectory;
  }

  public Object getRoot() {
    return root;
  }

  public Object getChild(Object parent, int index) {
    File directory = (File) parent;
    String[] children = directory.list();
    return new TreeFile(directory, children[index]);
  }

  public int getChildCount(Object parent) {
    File file = (File) parent;
    if (file.isDirectory()) {
      String[] fileList = file.list();
      if (fileList != null)
        return file.list().length;
    }
    return 0;
  }

  public boolean isLeaf(Object node) {
    File file = (File) node;
    return file.isFile();
  }

  public int getIndexOfChild(Object parent, Object child) {
    File directory = (File) parent;
    File file = (File) child;
    String[] children = directory.list();
    for (int i = 0; i < children.length; i++) {
      if (file.getName().equals(children[i])) {
        return i;
      }
    }
    return -1;

  }

  public void valueForPathChanged(TreePath path, Object value) {
    File oldFile = (File) path.getLastPathComponent();
    String fileParentPath = oldFile.getParent();
    String newFileName = (String) value;
    File targetFile = new File(fileParentPath, newFileName);
    oldFile.renameTo(targetFile);
    File parent = new File(fileParentPath);
    int[] changedChildrenIndices = { getIndexOfChild(parent, targetFile) };
    Object[] changedChildren = { targetFile };
    fireTreeNodesChanged(path.getParentPath(), changedChildrenIndices, changedChildren);

  }

  private void fireTreeNodesChanged(TreePath parentPath, int[] indices, Object[] children) {
    TreeModelEvent event = new TreeModelEvent(this, parentPath, indices, children);
    Iterator iterator = listeners.iterator();
    TreeModelListener listener = null;
    while (iterator.hasNext()) {
      listener = (TreeModelListener) iterator.next();
      listener.treeNodesChanged(event);
    }
  }

  public void addTreeModelListener(TreeModelListener listener) {
    listeners.add(listener);
  }

  public void removeTreeModelListener(TreeModelListener listener) {
    listeners.remove(listener);
  }

  private class TreeFile extends File {
    /**
*
*/
private static final long serialVersionUID = 1L;

public TreeFile(File parent, String child) {
      super(parent, child);
    }

    public String toString() {
      return getName();
    }
  }
}