The document is a Java program that allows users to edit a text file by inserting, deleting, and listing lines of text. It reads a specified file and prompts the user for commands to manipulate the text lines. There is also a requirement to modify the output to avoid displaying 'null' for empty lines.

1. import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
public class FileEdit {
public static List lines = new ArrayList();
public static void main(String[] args) throws IOException
{
Scanner s = new Scanner(System.in);
System.out.print("EDIT: ");
String fileName = s.nextLine();
BufferedReader br = new BufferedReader(new FileReader(new File(fileName)));
String str="";
int count=0;
while((str=br.readLine())!=null)
{
lines.add(count, str);
System.out.println((++count) + "> "+ str);
}
String text="";
String command = "";
System.out.print((++count)+"> ");
command=s.nextLine();
String commandArr[];
int flag;
while(!command.equals("E"))
{
flag=0;
commandArr = command.split("s");
if(commandArr[0].equals("I")) //Insertion
{
while(true)

2. {
if(commandArr.length==1&&flag!=2)
{
System.out.print((count)+"> ");
text = s.nextLine();
insertLine(text,count-1);
}
else if(commandArr.length==2&&flag!=2)
{
System.out.print((commandArr[1])+"> ");
count=Integer.parseInt(commandArr[1]);
text = s.nextLine();
insertLine(text,Integer.parseInt(commandArr[1])-1);
}
else
insertLine(text,count-1);
System.out.print((++count)+"> ");
command=s.nextLine();
commandArr = command.split("s");
if(commandArr[0].equals("I")||commandArr[0].equals("L")||commandArr[0].equals("D")||comm
andArr[0].equals("E"))
{
flag=1;
break;
}
else
{
flag=2;
text=command;
}
}
}
else if(commandArr[0].equals("L")) //Listing
{
printList();
}

3. else if(commandArr[0].equals("D")) //Deletion
{
if(commandArr.length==1)
{
deleteLine(count-1,count-1);
}
else if(commandArr.length==2)
{
deleteLine(Integer.parseInt(commandArr[1])-1,Integer.parseInt(commandArr[1])-1);
}
else if(commandArr.length==3)
{
deleteLine(Integer.parseInt(commandArr[1])-1,Integer.parseInt(commandArr[2])-1);
}
count=lines.size();
}
if(flag!=1)
{
System.out.print((count++)+"> ");
command = s.nextLine();
}
}
}
public static void insertLine(String text,int count)
{
if (count >= lines.size()) {
for(int i = lines.size(); i <= count; i++) {
lines.add(null);
}
}
lines.set(count,text);
}
public static void deleteLine(int start,int end)
{
for(int i=start;i<=end;i++)
lines.remove(i);

4. }
public static void printList()
{
for(int i=0;i "+lines.get(i));
}
}
Here is my output:
EDIT: textin.txt
1> The First Line
1>
2> And another line
3> I 3
3> The second line
4> One more line
5> L
1> null
2> null
3> The second line
4> One more line
5> D 2
3> L
1> null
2> The second line
3> One more line
4> E
How can I keep it from printing "null" after ">" and it just be blank. I need the output to look like
this:
1> The first line
2>
3> And another line
4> I 3
3> The second line
4> One more line
5> L
1> The first line

5. 2>
3> The second line
4> One more line
5> And another line
5> D 2
4> L
1> The first line
2> The second line
3> One more line
4> And another line
5> E