Develop Reference

Java - write string to file line by line vs one-liner / cannot convert String to String[]

Relatively new to programming. I want to read a URL, modify the text string, then write it to a line-separated csv textfile.
The read & modify parts run. Also, outputting the string to terminal (using Eclipse) looks fine (csv, line by line), like this;
data_a,data_b,data_c,...
data_a1,data_b1,datac1...
data_a2,data_b2,datac2...
.
.
.
But I'm unable to write the same string to file - it just becomes a one-liner (see my below for-loops, attempts no. 1 & 2);
data_a,data_b,data_c,data_a1,data_b1,datac1,data_a2,data_b2,datac2...
I guess I'm looking for a way to, in the FileWriter or BufferedWriter loops, convert the string finalDataA to array string (i.e. include the string suffix "[0]") but I have not yet found such an approach that would not give errors of the type "Cannot convert String to String[]". Any suggestions?
String data = "";
String dataHelper = "";
try {
URL myURL = new URL(url);
HttpURLConnection myConnection = (HttpURLConnection) myURL.openConnection();
if (myConnection.getResponseCode() == URLStatus.HTTP_OK.getStatusCode()) {
BufferedReader in = new BufferedReader(new InputStreamReader(myConnection.getInputStream()));
while ((data = in.readLine()) != null) {
dataHelper = dataHelper + "\n" + data;
}
in.close();
String trimmedData = dataHelper.trim().replaceAll(" +", ",");
String parts[] = trimmedData.split(Pattern.quote(")"));// ,1.,");
String dataA = parts[1];
String finalDataA[] = dataA.split("</PRE>");
// parts 2&3 removed in this example
// Console output for testing purpose - This prints out many many lines of csv-data
System.out.println(finalDataA[0]);
//This returns the value 1
System.out.println(finalDataA.length);
// Attempt no. 1 to write to file - writes a oneliner
for(int i = 0; i < finalDataA.length; i++) {
try (BufferedWriter bw = new BufferedWriter(new FileWriter(pathA, true))) {
String s;
s = finalDataA[i];
bw.write(s);
bw.newLine();
bw.flush();
}
}
// Attempt no. 2 to write to file - writes a oneliner
FileWriter fw = new FileWriter(pathA);
for (int i = 0; i < finalDataA.length; i++) {
fw.write(finalDataA[i] + "\n");
}
fw.close();
}
} catch (Exception e) {
System.out.println("Exception" +e);
}

Create the BufferedWriter and the FileWriter ahead of the for loop, not every time around it.

From your code comments, finalDataA has one element, so the for-loop will be executed only once. Try splitting finalDataA[0] into rows.
Something like this:
String endOfLineToken = "..."; //your variant
String[] lines = finalDataA[0].split(endOfLineToken)
BufferdWriter bw = new BufferedWriter(new FileWriter(pathA, true));
try
{
for (String line: lines)
{
bw.write(line);
bw.write(endOfLineToken);//to put back line endings
bw.newLine();
bw.flush();
}
}
catch (Exception e) {}

How to replace a word from txt file with regular expression in java

I want to replace a word from a txt file in java. I already have my regular expression and the method for reading the txt file from java. But i have no idea how to replace a word from it using mu regualar expression.
Any suggestion or example?

public class BTest
{
public static void main(String args[])
{
try
{
File file = new File("file.txt");
BufferedReader reader = new BufferedReader(new FileReader(file));
String line = "", oldtext = "";
while((line = reader.readLine()) != null)
{
oldtext += line + "\r\n";
}
reader.close();
// replace a word in a file
String newtext = oldtext.replaceAll("drink", "Love");
//To replace a line in a file
//String newtext = oldtext.replaceAll("This is test string 20000", "blah blah blah");
FileWriter writer = new FileWriter("file.txt");
writer.write(newtext);writer.close();
}
catch (IOException ioe)
{
ioe.printStackTrace();
}
}
}

Parse the file into one string.Then replace all instances of word with new word.
String response = "test string".replaceAll("regex here", "new text");
Then write the new text to a file
FileWriter writer = new FileWriter("out.txt");
writer.write(response);

I am using the epublib and I am trying to get the entire chapter of a book at a time

I am trying to get one chapter at a time of a book. I am using the Paul Seigmann library. However, I am not sure how to do it but I am able to get all the text from the book. Not sure where to go from there.
// find InputStream for book
InputStream epubInputStream = assetManager
.open("the_planet_mappers.epub");
// Load Book from inputStream
mThePlanetMappersBookEpubLib = (new EpubReader()).readEpub(epubInputStream);
Spine spine = new Spine(mThePlanetMappersBookEpubLib.getTableOfContents());
for (SpineReference bookSection : spine.getSpineReferences()) {
Resource res = bookSection.getResource();
try {
InputStream is = res.getInputStream();
BufferedReader r = new BufferedReader(new InputStreamReader(is));
String line;
while ((line = r.readLine()) != null) {
line = Html.fromHtml(line).toString();
Log.i("Read it ", line);
mEntireBook.append(line);
}
} catch (IOException e) {
}

I don't know if you're still looking for an answer, but...
I'm working on it too right now. This is the code I have to retrieve the content of all the epub file:
public ArrayList<String> getBookContent(Book bi) {
// GET THE CONTENTS OF ALL PAGES
StringBuilder string = new StringBuilder();
ArrayList<String> listOfPages = new ArrayList<>();
Resource res;
InputStream is;
BufferedReader reader;
String line;
Spine spine = bi.getSpine();
for (int i = 0; spine.size() > i; i++) {
res = spine.getResource(i);
try {
is = res.getInputStream();
reader = new BufferedReader(new InputStreamReader(is));
while ((line = reader.readLine()) != null) {
// FIRST PAGE LINE -> <?xml version="1.0" encoding="utf-8" standalone="no"?>
if (line.contains("<?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>")) {
string.delete(0, string.length());
}
// ADD THAT LINE TO THE FINAL STRING REMOVING ALL THE HTML
string.append(Html.fromHtml(formatLine(line)));
// LAST PAGE LINE -> </html>
if (line.contains("</html>")) {
listOfPages.add(string.toString());
}
}
} catch (IOException e) {
e.printStackTrace();
}
}
return listOfPages;
}
private String formatLine(String line) {
if (line.contains("http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd")) {
line = line.substring(line.indexOf(">") + 1, line.length());
}
// REMOVE STYLES AND COMMENTS IN HTML
if ((line.contains("{") && line.contains("}"))
|| ((line.contains("/*")) && line.contains("*/"))
|| (line.contains("<!--") && line.contains("-->"))) {
line = line.substring(line.length());
}
return line;
}
As you may have notice I need to improve the filter, but I have every chapter of that book in my ArrayList. Now I just need to call that ArrayList like myList.get(0); and is done.
To show the text in a proper way, I'm using the bluejamesbond:textjustify library (https://github.com/bluejamesbond/TextJustify-Android).
It is easy to use and powerful.
I hope it helps you, and if anybody finds a better way to filter that html, notice me, please.

Replace String in file using marker in Java

i have problem when try to replacing String in File.
in my file i have :
<!-- Header -->
<header fontName="Arial" size="24"/>
<!-- Content -->
<content>
<fontName="Arial" size="11"/>
</content>
How to replace fontName and size just for <!-- Header --> ?
This is my code for replace
public class StringReplacement {
public static void main(String args[])
{
try
{
File file = new File("file.xml");
BufferedReader reader = new BufferedReader(new FileReader(file));
String line = "", oldtext = "";
while((line = reader.readLine()) != null)
{
oldtext += line + "\r\n";
}
reader.close();
// replace a word in a file
//String newtext = oldtext.replaceAll("drink", "Love");
//To replace a line in a file
String newtext = oldtext.replaceAll("Arial", "Times New Roman");
FileWriter writer = new FileWriter("file.xml");
writer.write(newtext);
writer.close();
}
catch (IOException ioe)
{
ioe.printStackTrace();
}
}
}
But it just replace all the text to be replaced.

If you are sure that this is the format of the file you can simply do the following:
String newtext = oldtext.replaceAll("header fontName=\"Arial\"", "header fontName=\"Times New Roman\"");
By the way use a StringBuilder to append Strings.

In your read loop while((line = reader.readLine()) != null) you could test if you found the <!-- Header --> line (and not yet the <!-- Content --> line), and do your replace only in the header block.
boolean inHeader == false;
while((line = reader.readLine()) != null) {
if (line.equals("<!-- Header -->")) {
inHeader = true;
} else if (line.equals("<!-- Content -->")) {
inHeader = false;
}
if (inHeader) {
line = line.replaceAll("Arial", "Times New Roman");
}
oldtext += line + "\r\n";
}
And remove the line
String newtext = oldtext.replaceAll("Arial", "Times New Roman");
EDIT: It would probably be cleaner to detect arbitrary tags rather than hardcoding Header and Content. That would require a regular expression to match <!-- (tag) --> and test if tag is equal to "Header", but this approach is easier, of course.

Java String Replacement

I have a string like this in a file
<script>
Evening</script>
I have written a code to replace this string but it's not identifying the newline character
i,e. I want to replace above string with:
<h1>Done</h1>
code goes like this:
package stringreplace;
import java.io.*;
import org.omg.CORBA.Request;
public class stringreplace {
/**
* #param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
FileReader fr = null;
BufferedReader br = null;
try
{
fr = new FileReader("G://abc.html");
br = new BufferedReader(fr);
String newtext="";
String line="";
String matchExist1 = "<script>\r\nEvening</script>";
String newpattern = "<h1>Done</h1>";
String matchExist2 = "</body>";
String newpattern2 = "<script>alpha</script></body>";
StringBuffer sb = new StringBuffer();
while((line=br.readLine())!=null)
{
int ind2 = line.indexOf(matchExist1);
System.out.println(ind2);
int ind3 = line.indexOf(matchExist2);
if((ind2==-1) || (ind3==-1))
{
line = line.replaceFirst(matchExist1,newpattern);
line = line.replaceFirst(matchExist2,newpattern2);
sb.append(line+"\n");
}
//sb.append(line+"\n");
else if((ind2!=-1) || (ind3!=-1))
{
String tag = "</body>";
line = line.replaceFirst("</body>",tag);
sb.append(line+"\n");
}
}
br.close();
FileWriter fw = new FileWriter("G://abc.html");
fw.write(sb.toString());
fw.close();
System.out.println("done");
System.out.println(sb);
}
catch (Exception e)
{
System.out.println(e);
}
}
}
But it is not identifying newline character.

Since you are reading only one input line at a time you can hardly expect to match a pattern that spans two lines.You must first fix your read to have a least two lines in it. Once you've done that, #sterna's answer will do the trick

I think you can't be sure about how your newline looks like. So I would not match for a specific sequence instead use \s+ this is at least one whitespace character and all newline characters are included.
String matchExist1 = "<script>\\s+Evening</script>";
Edit:
Of course, you have to fix at first the problem mgc described (+1). And then you can make use of my answer!