Reading In A Resource Folder

[Nick Rowe]

Hi Guys Im New to Java, This is actually the second phase of my first program. I'll explain my issue first. I need to read in the contents of a resource folder into my program. Currently it only reads in one file.

Can anyone help, for example my code below is designed to extract the data between two strings and return that data as another string.

For each occurance of said string it is captured and stored within an array, the array is then sorted and its contents are then printed out in a new document.

So basically I now need to test my program against several files rather than just the one.

Can someone please help. thank you for your time, code will follow.
Regards Nick

/**import java librarys*/
import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.Collections;
import java.util.List;
import java.io.PrintWriter;
import java.io.FileWriter;


/** class to find string */
public class Find {
	BufferedReader br = null;

	/** method to read html file line by line and return string to tore in array */
	public Find() throws java.io.IOException {
		try {
			/** read in file */
			br = new BufferedReader(
					new FileReader(
							"C:/Documents and Settings/Kieren McDonald/Desktop/Nick/Java/Test/timelinemanager_resource.htm"));
			/**
			 * declaring string identifiers for beginning and end of string
			 * aswel as one other line string to store the data between
			 */
			String resourceline = null;
			String beg = "<@dynamichtml ";
			String end = "@>";
			ArrayList<String> arrayList = new ArrayList<String>();
			/** while line is not equal to null then find 3 string values */
			while ((resourceline = br.readLine()) != null) {
				resourceline = find(beg, end, resourceline);

				/**
				 * if line is not equal to null store line in array list adding
				 * a resource name
				 */
				if (resourceline != null) {
					resourceline= resourceline.trim();
					arrayList.add(resourceline);
					
				}

			}
			sortAndPrint(arrayList);
			writeResults(arrayList, "C:\\Documents and Settings\\Kieren McDonald\\Desktop\\Nick\\Java\\Test\\filetest.txt");
		} catch (FileNotFoundException ex) {
			ex.printStackTrace();
		} finally {
			br.close();
		}
	}

	/** method to sort and print the array collection */
	private void sortAndPrint(List<String> results) {
		Collections.sort(results,String.CASE_INSENSITIVE_ORDER);
		for (String resourceline : results)
			System.out.println(resourceline);
	}

	/** method to find the value between the beginning and end of a string    
	*/ 
	public String find(String beg, String end, String resourceline) {
		/** match pattern to store string between strings and match to line */
		Pattern p = Pattern.compile(beg + "(.*)" + end);
		Matcher m = p.matcher(resourceline);
		return m.find() ? resourceline.substring(m.start(1), m.end(1)) : null;
	}
	/** method to print the results of the array into a new document */
	private void writeResults(ArrayList<String> arrayList, String filename) {   
    try {   
        PrintWriter writer = new PrintWriter( filename );   
  
        for (String resourceline : arrayList)   
            writer.println( resourceline );   
            System.err.println( "Your Data Has Been Written To The File Successfully" );  
        writer.close();   
    }   
    catch( Exception e ) {   
        System.out.println( "can't create output file \"" + filename + "\"" );   
        e.printStackTrace();   
    }   
} 

	/** main method to find the resource name calling */
	public static void main(String[] args) throws IOException {
		Find findResources = new Find();
	}
}

[akhter wahab]

 
File myDir = new File("C:/myDir");// your folder address
if( myDir.exists() && myDir.isDirectory())//check folder exists and have more files too { 
File[] files = myDir.listFiles() //gettting file list
for(int i=0; i < files.length; i++){
System.out.println(files[i]);
}
}  

[Nick Rowe]

Hi akhter, im not sure to implement this in my program sorry.

As i mentioned in my post, this is actually an editation made to my first program a few weeks back, i havn't been learning java for very long at all so this is all new to me.

With your suggested code i removed the buffered reader and filereader references from my code, replacing them with your new directory code and had many stack trace errors.

This may sound cheeky but is there any chance you could copy your code into mine as this will give me the best way to reference folders accuractely if I ever need to again in the future.
I plan on documenting the method for my own references.

Thank you very much for your post

[akhter wahab]

this is the way you may use

 /*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */


import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.Collections;
import java.util.List;
import java.io.PrintWriter;
import java.io.FileWriter;

/** class to find string */
public class Find {

    BufferedReader br = null;

    /** method to read html file line by line and return string to tore in array */
    public Find(String fileName, String begin, String end,String whereToWrite) throws java.io.IOException {
        try {
            /** read in file */
            String resourceline = null;
            ArrayList<String> arrayList = new ArrayList<String>();
            File myDir = new File(fileName);
            if (myDir.exists() && myDir.isDirectory()) {
                File[] files = myDir.listFiles();
                for (int i = 0; i < files.length; i++) {
                    br = new BufferedReader(new FileReader(files[i]));
                    while ((resourceline = br.readLine()) != null) {
                        resourceline = find(begin, end, resourceline);
                        if (resourceline != null) {
                            resourceline = resourceline.trim();
                            arrayList.add(resourceline);

                        }

                    }
                    sortAndPrint(arrayList);
                    writeResults(arrayList, whereToWrite);
                }
            } else {
                System.out.println("This is not a directory");
            }

            /**
             * declaring string identifiers for beginning and end of string
             * aswel as one other line string to store the data between
             */
            /** while line is not equal to null then find 3 string values */
        } catch (FileNotFoundException ex) {
            ex.printStackTrace();
        } finally {
            br.close();
        }
    }

    /** method to sort and print the array collection */
    private void sortAndPrint(List<String> results) {
        Collections.sort(results, String.CASE_INSENSITIVE_ORDER);
        for (String resourceline : results) {
            System.out.println(resourceline);
        }
    }

    /** method to find the value between the beginning and end of a string
     */
    public String find(String beg, String end, String resourceline) {
        /** match pattern to store string between strings and match to line */
        Pattern p = Pattern.compile(beg + "(.*)" + end);
        Matcher m = p.matcher(resourceline);
        return m.find() ? resourceline.substring(m.start(1), m.end(1)) : null;
    }

    /** method to print the results of the array into a new document */
    private void writeResults(ArrayList<String> arrayList, String filename) {
        try {
            PrintWriter writer = new PrintWriter(filename);

            for (String resourceline : arrayList) {
                writer.println(resourceline);
            }
            System.err.println("Your Data Has Been Written To The File Successfully");
            writer.close();
        } catch (Exception e) {
            System.out.println("can't create output file \"" + filename + "\"");
            e.printStackTrace();
        }
    }

    /** main method to find the resource name calling */

}
   

use appropriate perameters while making the object of the class in MAIN

[Nick Rowe]

Thank you for that, thats made things alot clearer.

However why can't I use my previous main method

/** main method to find the resource name calling */
public static void main(String[] args) throws IOException {
Find findResources = new Find();
}

I have tried with this but for some reason it throws an error at the n in new Find();

regards Nick

[tushar bhasme]

that's because now there is no Find() constructor ... the constructor signature has now changed to "public Find(String fileName, String begin, String end,String whereToWrite)" ... so you need to pass in the directory name(eg "C:/myDir"), beginning string (eg "<@dynamichtml" ), end string(eg "@>>), targer file name (eg "C:\\Documents and Settings\\Kieren McDonald\\Desktop\\Nick\\Java\\Test\\filetest.txt")...
The code will read all the files present in the folder myDir...

Another thing i would suggest is keep all this code in a method and call it instead of putting it in the constructor...

[Nick Rowe]

Ok im with you however when i use the method below

/** main method to find the resource name calling */  
    public Find(String fileName, String begin, String end,String whereToWrite)
               throws java.io.IOException
        {
                "myDir", "<@dynamichtml", "@>", "C:\\Documents and Settings\\Kieren McDonald\\Desktop\\Nick\\Java\\Test\\filetest.txt"}
	} 

I get two errors relating to the directory of my file write destination parameter, why is this?


One says this is not a statment and references the above. The second expects a semi colon ; in the middle of the write path parameter.

regards Nick

[tushar bhasme]

can you post the errors?

you may have to use the full path for source directory too (if its not a part of the working directory)...

[tushar bhasme]

public Find(String fileName, String begin, String end,String whereToWrite)throws java.io.IOException {"myDir", "<@dynamichtml", "@>", "C:\\Documents and Settings\\Kieren McDonald\\Desktop\\Nick\\Java\\Test\\filetest.txt"}
}

i am not sure what are you trying to achieve by doing the above...

all you need to do is keep the code as it was earlier..

in the main, do this..

new Find("myDir", "<@dynamichtml", "@>", "C:\\Documents and Settings\\Kieren McDonald\\Desktop\\Nick\\Java\\Test\\filetest.txt");

[Nick Rowe]

Find.java 93 :not a statement:
public Find(String fileName, String begin, String end,String whereToWrite) throws java.io.IOException {"myDir", "<@dynamichtml", "@>", "C:\\Documents and Settings\\Kieren McDonald\\Desktop\\Nick\\Java\\Test\\filetest.txt"}

error points to s in Desktop

Find.java 93: ';' expected

same except this time points to N in Nick

[Nick Rowe]

Ok Hang on, I realise I was being a bit of a gimp just then.
I've corrected myself, so now I have

 
/** main method to find the resource name calling */  
    public Find(String fileName, String begin, String end,String whereToWrite) throws java.io.IOException 
	{
	fileName="myDir";
	begin="<@dynamichtml";
	end="@>";
	whereToWrite="C:\\Test\\filetest.txt";} 
 

And am getting one error

Find.java93:
Find<java.lang.string.java.lang.string (repeats)
String is already defined in Find

public Find <String fileName, String being, String end, String whereToWrite> throws java.io.IOexception

error points to io ???

regards Nick

[Hunter McMillen]

What you have right here:

  public Find(String fileName, String begin, String end,String whereToWrite) throws java.io.IOException 
{
         "myDir", "<@dynamichtml", "@>", "C:\\Documents and Settings\\Kieren McDonald\\Desktop\\Nick\\Java\\Test\\filetest.txt"
}   

is not valid.

You need to create main method, then create a new Find object using those values inside the main method.

Ex:

   
public static void main(String[] args)
{
       Find f = new Find(arg1, arg2, arg3, etc.....);
}
 

Hunter

[Hunter McMillen]

Ok you fixed the last thing I pointed out before I submitted it

What you are doing now is also wrong though.

Inside your find constructor you should be assigning fileName and all of the other class attributes to the values coming in from the constructor. If you just leave the values hardcoded in the constructor you have you will never have an object with different data unless you manually switch the code.

Ex:

    
public class Student
{
      String name;
      int age, id;

      public Student(String name, int age, int id)
      {
           this.name = name; //this refers to variables inside this class, in this case name, age, and id we declared above.
           this.age    = age;
           this.id       = id;
      }
}

public class TestStudent
{
      public static void main(String[] args)
      {
           Student s = new Student("John", 25, 009876); //this creates a new student and stores the name age and id inside the variables 
                                                                              //we defined in the Student class
      }
}

Hope this helps,
Hunter

[Nick Rowe]

Morning Hunter, lol when I mentioned before that I was new to Java I Literally Meant brand new lol. Altho i do grasp the concepts of pseudo code and have done bits of coding using javascript and some perl. Java is new to me.

Normally everything I do revolves around html, css, javascript and content management but this is really new to me and I have no teacher so im having to teach myself at the moment.
Anyway i wanted to say thank you, your examples were very helpful.

Altho this morning I read your post from yesterday evening had myself a can of Red Bull and a little read on arguements from the Oracle site and wrote myself a solution lol. I was soo chuffed lol im sure its no biggy but I was pretty happy. Anyway below is what I've used.

Thanks again

/** main method to find the resource name calling */  
	public static void main(String[] args) throws IOException
    {   
       Find f = new Find(
              "myDir",
              "<@dynamichtml",
              "@>",
              "C:\\Documents and Settings\\Kieren McDonald\\Desktop\\Nick\\Java\\Test\\filetest.txt");   
	}

[tushar bhasme]

Nick,

If you read close, this is exactly what i told you in my last post... you could save a lot of trouble...