write newline into a file

问题

considering the following function

private static void GetText(String nodeValue) throws IOException {

   if(!file3.exists()) {
       file3.createNewFile();
   }

   FileOutputStream fop=new FileOutputStream(file3,true);
   if(nodeValue!=null)
       fop.write(nodeValue.getBytes());

   fop.flush();
   fop.close();

}

what to add to make it to write each time in the next line?

for example i want each words of a given string in a seperate lline for example:

i am mostafa

writes as:

 i
 am
 mostafa

回答1:

To write text (rather than raw bytes) to a file you should consider using FileWriter. You should also wrap it in a BufferedWriter which will then give you the newLine method.

To write each word on a new line, use String.split to break your text into an array of words.

So here's a simple test of your requirement:

public static void main(String[] args) throws Exception {
    String nodeValue = "i am mostafa";

    // you want to output to file
    // BufferedWriter writer = new BufferedWriter(new FileWriter(file3, true));
    // but let's print to console while debugging
    BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(System.out));

    String[] words = nodeValue.split(" ");
    for (String word: words) {
        writer.write(word);
        writer.newLine();
    }
    writer.close();
}

The output is:

i
am
mostafa

回答2:

Change the lines

if(nodeValue!=null)
    fop.write(nodeValue.getBytes());

fop.flush();

to

if(nodeValue!=null) {
    fop.write(nodeValue.getBytes());
    fop.write(System.getProperty("line.separator").getBytes());
}

fop.flush();

Update to address your edit:

In order to write each word on a different line, you need to split up your input string and then write each word separately.

private static void GetText(String nodeValue) throws IOException {

    if(!file3.exists()) {
        file3.createNewFile();
    }

    FileOutputStream fop=new FileOutputStream(file3,true);
    if(nodeValue!=null)
        for(final String s : nodeValue.split(" ")){
            fop.write(s.getBytes());
            fop.write(System.getProperty("line.separator").getBytes());
        }
    }

    fop.flush();
    fop.close();

}

回答3:

Files.write(Paths.get(filepath),texttobewrittentofile,StandardOpenOption.APPEND ,StandardOpenOption.CREATE);    

This creates a file, if it does not exist If files exists, it is uses the existing file and text is appended If you want everyline to be written to the next line add lineSepartor for newline into file.

String texttobewrittentofile = text + System.lineSeparator();

回答4:

if(!file3.exists()){
    file3.createNewFile();
}
FileOutputStream fop=new FileOutputStream(file3,true);
if(nodeValue!=null) fop.write(nodeValue.getBytes());

fop.write("\n".getBytes());

fop.flush();
fop.close();

You need to add a newline at the end of each write.

回答5:

Solution:

in WINDOWS you should write "\r\n" for a new line.

回答6:

You could print through a PrintStream.

PrintStream ps = new PrintStream(fop);
ps.println(nodeValue);
ps.close();

回答7:

the other answers should work. however I wanna mention

from java doc:

FileWriter is meant for writing streams of characters. For writing streams of raw bytes, consider using a FileOutputStream.

reading your method codes, you are about to write String to the file, what you were doing is convert String to raw bytes, then write so I think using FileWriter is not a bad idea.

And for the newline problem, Writer has method .write(String), which is convenient to use.

回答8:

Or you could use something like the following. Pay attention to "\n":

/**
 * Created by mona on 3/26/16.
 */
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.BufferedReader;
public class FileExample {


    public static void main (String[] args) throws java.io.IOException {

        File newFile = new File("tweet.txt");
        FileWriter fileWriter = new FileWriter(newFile);
        fileWriter.write("Mona Jalal");
        fileWriter.append("\nMona Mona");
        fileWriter.close();
        FileReader fileReader = new FileReader(newFile);
        BufferedReader bufferedReader = new BufferedReader(fileReader);
        String line;
        while ((line = bufferedReader.readLine()) != null) {
            System.out.println(line);
        }
        fileReader.close();
        bufferedReader.close();



    }
}

回答9:

just use \r\n for endline if you are using windows operating system.

来源：https://stackoverflow.com/questions/8491687/write-newline-into-a-file