Read a particular info and write to a txt file using java

Question

am new to java programming I need a program to read a certain information from a file and select the particular informationwhich is needed and then write this particular information into a text file .

{

 BufferedReader in = new BufferedReader (newFileReader("C:/Users/ngorentl/"));
    String info = "";
    String info1 = "";
    int startLine = 111 ;
    int endLine = 203 ;
    int sl = 221;
    int el =325;

// reading only the specific info which is needed and that is printing in the console

   for (int i = 0; i < startLine; i++) { info = in.readLine(); }
    for (int i = startLine; i < endLine + 1; i++) {
        info = in.readLine();
        System.out.println(info);
    }
       for (int j = 203; j < sl; j++) { info1 = in.readLine(); }
        for (int j = sl; j < el + 1; j++) {
            info1 = in.readLine();
           System.out.println(info1);
        }

     // having a problem from here i dont know whether this is the correct approach 
        File fin = new File(info); // getting an error here
        FileInputStream fis = new FileInputStream(fin);
        BufferedReader is = new BufferedReader(new InputStreamReader(fis));     
        FileOutputStream fos = new FileOutputStream("hh.txt");
        OutputStreamWriter osw= new OutputStreamWriter(fos);
        BufferedWriter bw = new BufferedWriter(osw);
        String aLine = null;
        while ((aLine = is.readLine()) != null) {
        bw.write(aLine);
        bw.newLine();
        bw.flush();
        bw.close();
        is.close();
        }
        in.close();

}

I have edited my question with the code am trying i hope you'll get an idea now — Naimisha Gorentla, Feb 24 '17 at 10:36
You are closing the streams after the first read line, you should close them after the `while` loop . — Arnaud, Feb 24 '17 at 10:39
OK is that the only mistake because i see a error here File fin = new File(info); — Naimisha Gorentla, Feb 24 '17 at 10:43
Possible duplicate of http://stackoverflow.com/questions/4716503/reading-a-plain-text-file-in-java and/or http://stackoverflow.com/questions/2885173/how-do-i-create-a-file-and-write-to-it-in-java — sazzad, Feb 25 '17 at 12:05

Anurag Awasthi · Accepted Answer · 2017-03-07T13:58:30.720

0

File fin = new File(String fileName) is the correct syntax. eg. File fin = new File("C:\abc.txt");

[UPDATE] Assuming your question is about writing a String to file. In Java 7

try(  PrintWriter out = new PrintWriter( "filename.txt" )  ){
out.println( info); 
}

In Java 6 or below, use

try {
        BufferedWriter out = new BufferedWriter(new FileWriter("sample.txt"));
        out.write(info);
        out.close();
    }
    catch (IOException e)
    {
        System.out.println("Exception ");       
    }

and possible correction of your code, so variable info has all that information

for (int i = startLine; i < endLine + 1; i++) {
    info    +=   in.readLine();
}

    System.out.println(info);

edited Mar 07 '17 at 13:58

answered Feb 24 '17 at 10:20

Anurag Awasthi

238
2
13

my information is stored in "info" so how can i specify in the syntax ? – Naimisha Gorentla Feb 24 '17 at 11:36
You're making a simple job rather complex by your terminologies. What is this "info" you're talking about? Suppose following is the content zin.txt. "Abc def dog cat xyz opqr qwerty hah lee law tekken pass ip 10.10.20.33 abcdef some other text" – Anurag Awasthi Feb 24 '17 at 11:39
info = in.readLine(); ---> which ever information needed i've stored it in here in the "info" now how do i write it into a text file. – Naimisha Gorentla Feb 24 '17 at 11:46
only the last line of my info is writing – Naimisha Gorentla Feb 24 '17 at 12:03

Read a particular info and write to a txt file using java

1 Answers1