Pls help i have to give this assighment

Question

1. Construct a class ReverseContent, which makes a copy of the input file.
Read each line in the file and print the line in the reverse order in the copied file.
If the file is blank give an error message that the input file is blank.
2. Construct a class FileCreation, which takes NAME & Some String value from User. Then creates a file
with name as <NAME>_<TODAY_DATETIME in the format 20070905163004> and write the string value the user has given to the file.
Once it is written successfully, as a next method parse the file and read the file content and print it to the console
3. Construct a program WordCount, which counts number of chars, words and lines of the text file. Space is      
counted as a character. Empty rows are counted as lines. "Word" will represent a string. Method Character.isLetter(char ch) might be useful? Look at the java.lang.Character from Java API documentation!
4 Write and run a Java program that enters an 8-digit string for a birthdate from the keyboard. The first                
two digits in the string are the month of birth, the next two are the day and the remaining four are the year. The Java program should squeeze out these substrings and display it on the screen as follows:
     month of birth:
     day of birth:
     year of birth:
     Also display the input date of birth in the format 4th September 2007
     Try to add exception handling for the case if the month and day are out of range.
5. Write a text file counter.dat which contains the integer 0. Then write a Java application that reads
this file and increments the integer by one. Then the new integer is written back to the file counter.dat . This means every time we open and close the file the integer number is incremented by 1.
6. Write a Java application using two for loops to produce the following pattern of asterisks.
7. Read in three integers of data type long from the keyboard. Then add the three numbers. Type convert
the sum to data type double and divide by 3.0 (data type double ) to find the arithmetic mean.
pls provide codes/ideas ASAP

Answer 1

hi,
>>Construct a class ReverseContent, which makes a copy of the input file.
Read each line in the file and print the line in the reverse order in the copied file. Solution to this problem:
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
public class ReverseContent {
    /** Creates a new instance of ReverseContent */
    public ReverseContent() {
    public static void main(String args[])
        FileInputStream fin=null;
        FileOutputStream fout=null;
        try {
            if(!(args.length>=2))
                System.out.println("run as: java ReverseContent sourcefilepath destinationfilepath");
                return;
            fin=new FileInputStream(args[0]);
            fout=new FileOutputStream(args[1]);
            int temp=0;
            String content="";
            while((temp=fin.read())!=-1)
               content+=String.valueOf((char)temp) ;
            fin.close();
            content=content.trim();
            StringBuffer sbuf=new StringBuffer(content);
            sbuf.reverse();
            content=sbuf.toString();
            fout.write(content.getBytes());
            fout.flush();
            fout.close();
        } catch (FileNotFoundException ex) {
            ex.printStackTrace();
        catch(IOException ex){
            ex.printStackTrace();
        finally
            try {
                if(fin!=null)
                    fin.close();
                if(fout!=null)
                    fout.close();
            } catch (IOException ex) {
                ex.printStackTrace();
}