JSP : Write Log Datewise

Writing logs in JSP..

Here is the code you can use to write log Every day Datewise(dd-mm-yyyy).
You can use in in you code JSP or Servlet.

you need to import following

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

Add following lines in your code accordingly


// open file to write date wise logs
SimpleDateFormat df = new SimpleDateFormat("dd-MMMM-yyyy");
java.util.Date date = new java.util.Date();
String today = df.format(date);

//Provide file in which log to be written
BufferedWriter outlog = outlog = new BufferedWriter(new FileWriter("D:\\Log_"+today+".log", true));

outlog.write("1st Line \n");........... //used "\n" as line seperator
outlog.write("2nd Line ");
outlog.newLine(); .....................//used outlog.newLine() as line seperator
outlog.write("3rd Line ");


//flush BufferedWriter at the end
outlog.flush();
outlog.close();

Java : Sorting ArrayList in Ascending and Descending order

Simple Program to sort Arraylist in Ascending and Descending order. U can also sort String,Float,Double.. etc in ArrayList.

ArrayList can be sorted using inbuilt java 1.5 class method Collections.sort(..).

Here is code, save it as file : Sorting.java


import java.util.*;

public class Sorting
{
public static void main(String[] args)
{
//Initilize ArrayList
ArrayList<Integer> arrayList = new ArrayList<Integer>();//also it can sort String,Float,Double.. etc

//creating Random numbers
//Random is a inbuilt java class in 1.5 in util package
Random random = new Random();

//putting Values
for(int i=1;i<=10;i++)
{
int temp = random.nextInt(100);//get random int values between 0 and 100
arrayList.add(temp);
}

//Sorting ArrayList
System.out.println("Before Sorting..");
System.out.println(arrayList);

Collections.sort(arrayList);//Sorting using sort method, default ascending sort

System.out.println("After Sorting Ascending..");
System.out.println(arrayList);

//useing Comparator to sort in descending order
Comparator<Integer> comparator = Collections.reverseOrder();
Collections.sort(arrayList,comparator);//Descending sorting using sort method

System.out.println("After Sorting Descending..");
System.out.println(arrayList);
}
}

Java : Simple Program to Create zip file.

It can be used to zip both a file or a Directory. Directory is ziped along with its subdirectory structure. Just Provide the proper source and run the code.


import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;

public class CreateZip {
   
    //function to zip a single file
    //Parameters List :
    //zipSrc : source file which to be ziped
    //zipName : Give desire name to zip file
    //destination folder where to create zip file
    public void zipFile(File zipSrc,String zipName,String destFolder) {
       
        System.out.println("zipFile :: "+zipSrc.getPath()+" "+zipName+" "+destFolder);
       
        try {           
                   
            ZipOutputStream zos = new ZipOutputStream(new FileOutputStream(destFolder+File.separator+zipName));
                   
            FileInputStream fis = new FileInputStream(zipSrc);
           
            ZipEntry zipEntry = new ZipEntry(zipSrc.getName());
           
            zos.putNextEntry(zipEntry);
           
            int bytes = 0;
            byte[] buffer = new byte[2156];
           
            bytes = fis.read(buffer);
           
            while (bytes != -1) {
                zos.write(buffer, 0, bytes);
                bytes = fis.read(buffer);
            }
           
            fis.close();
            zos.flush();
            zos.close();
           
        } catch (Exception e) {
           
            System.out.println("Exception :: "+e);
           
        }
    }
   
    //function to zip a folder containing multiple files
    //Parameters List :
    //zipSrc : source folder which to be ziped
    //zipName : Give desire name to zip file
    //destination folder where to create zip file
    public void zipDirectory(File zipSrc,String zipName,String destFolder) {
       
        System.out.println("zipDirectory :: "+zipSrc.getPath()+" "+zipName+" "+destFolder);
       
        try {
           
            ZipOutputStream zos = new ZipOutputStream(new FileOutputStream(destFolder+File.separator+zipName));
           
            zipDirectoryUtil(zipSrc.getPath(),zos,"");
            zos.close();       
        }
        catch (Exception e) {
           
            e.printStackTrace();
        }
       
    }
   
    public void zipDirectoryUtil(String directory,ZipOutputStream zos,String path) {
       
        try {
           
            File zipDir = new File(directory);
           
            String[] allFiles = zipDir.list();
           
            int bytes = 0;
            byte[] buffer = new byte[2156];
           
            for (String eachFile : allFiles) {
               
                File file = new File(zipDir,eachFile);
               
                if(file.isDirectory()) {
                   
                    zipDirectoryUtil(file.getPath(),zos,path+file.getName()+File.separator);
                    continue;
                }
               
            FileInputStream fis = new FileInputStream(file);
           
            ZipEntry zipEntry = new ZipEntry(path+file.getName());
           
            zos.putNextEntry(zipEntry);
           
            bytes = fis.read(buffer);
           
            while (bytes != -1) {
                zos.write(buffer, 0, bytes);
                bytes = fis.read(buffer);
            }
            fis.close();
           
            }
        }
        catch (Exception e) {
           
            e.printStackTrace();
        }
    }
   
    public static void main(String[] args) {
       
        CreateZip obj = new CreateZip();
       
        obj.zipFile(new File("C:\\MY\\Code\\Photo.jpg"),"img.zip","D:\\Test\\data");
       
        obj.zipDirectory(new File("C:\\MY\\Code\\com"),"com.zip","D:\\Test\\data");

    }

}

Java : Simple Program for Unzipping a File

Just provide a zip file which to be unziped and run the code.


import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.util.Enumeration;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;

public class Unziping {
  
    //Function to unzip a file, provide source zip file and destination directory where to unzip a file
    public void unzip(File zipFile,String destFolder) {
      
        System.out.println("Unzip :: "+zipFile.getPath()+" into "+destFolder);
      
        try {
            ZipFile zip = new ZipFile(zipFile);
          
            File dest = new File(destFolder);
          
            Enumeration files = zip.entries();
          
            File file;
            FileOutputStream fos;
          
            int bytes = 0;
            byte[] buffer = new byte[2156];
          
            while (files.hasMoreElements()) {
              
                ZipEntry entry = (ZipEntry)files.nextElement();
              
                InputStream eis = zip.getInputStream(entry);
                file = new File(dest.getAbsolutePath() + File.separator + entry.getName());
              
                if (entry.isDirectory()) {
                    file.mkdirs();
                    continue;
                }
                else {
                    file.getParentFile().mkdirs();
                    file.createNewFile();
                }
              
                fos = new FileOutputStream(file);
              
                while ((bytes = eis.read(buffer)) != -1) {
                    fos.write(buffer, 0, bytes);
                  }
              
                fos.close();              
            }          
          
        } catch (Exception e) {
          
            e.printStackTrace();
        }
    }
  
    public static void main(String[] args) {
      
        Unziping obj = new Unziping();
      
        obj.unzip(new File("C:\\MY\\Code\\com.zip"),"C:\\MY\\Code");
    }

}

JSP : Simple File Uploading Codes.

We will see how to upload a file using JSP, you can upload a file to your desire location with desire name. Please see the simple self explanatory codes below.

Please add below mentioned jar files in your applications classpath.

• commons-fileupload-1.2.jar (http://commons.apache.org/fileupload)
• commons-io-1.4.jar (http://commons.apache.org/io)

1st HTML interface (can be used in JSP as well)

FileUploadingInterface.HTML


<HTML>
<HEAD>
<TITLE>File Uploading Interface</TITLE>
</HEAD>
<BODY>
<center>
<h3>Simple File Uploading Example</h3>
<form action="ProcessUploadedFile.jsp" method="post" enctype="multipart/form-data">
Name <input type="text" name="userName"> (optional) </br></br>
File <input type="file" name="file1"> </br></br> <!-- Here You Can Add more numbers of Files For Uploading -->
<input type="submit" value="Submit">
</form>
</center>
</BODY>
</HTML>



2nd JSP code


ProcessUploadedFile.jsp


<%@ page import="java.io.*" %>
<%@ page import="java.util.*"%>
<%@ page import="org.apache.commons.fileupload.servlet.ServletFileUpload"%>
<%@ page import="org.apache.commons.fileupload.disk.DiskFileItemFactory"%>
<%@ page import="org.apache.commons.fileupload.*"%>
<%
boolean isMultipart = ServletFileUpload.isMultipartContent(request);

if (!isMultipart)
{
}
else
{
FileItemFactory factory = new DiskFileItemFactory();
ServletFileUpload upload = new ServletFileUpload(factory);
List items = null;
try
{
items = upload.parseRequest(request);
}
catch (FileUploadException e)
{
e.printStackTrace();
}

Iterator itr = items.iterator();

while (itr.hasNext())
{
FileItem item = (FileItem) itr.next();

//Get Other Form Fileds Values in this Block
if (item.isFormField())
{
String itemName = item.getFieldName();
String itemValue = item.getString();
String name = "";
if (itemName.equals("userName"))
name = item.getString();

out.println("User Name "+name);
}
//Get File type Values Here, it could be one or multiple File
else
{
try
{
String itemName = item.getName();

//userFieldName is what u provided in html file
String userFieldName = item.getFieldName();

if(itemName != null)
{
if(itemName.equals(""))
{
//If Nothing Uploaded
out.println("No File Uploaded");
}
else
{
//Provide Destination Folder, Where Uploaded File to be saved
boolean folderMade = (new File("d:/UploadedFileFolder")).mkdirs();

// This is required to filter out file name from complete file path.
int idx = itemName.lastIndexOf("\\");

String filename = "";

if(idx > -1)
{
//in case of IE, it sends complete path. Hence only file name must be filtered out.
idx=idx+1;
filename = itemName.substring(idx);
}
else
{
//in case of other borwsers, its just filename
filename = itemName;
}

File savedFile = new File("d:/UploadedFileFolder/"+filename);
item.write(savedFile);

//Get path of the saved file
String path = savedFile.getPath();

out.println("File Uploaded Sucessfully "+path);

}
}
}//try
catch(Exception e)
{
e.printStackTrace();
}
}//else
}//while
}//else
%>