Develop Reference

split method to output values under each other when reading from a file

My code works fine however it prints the values side by side instead of under each other line by line. Like this:
iatadult,DDD,
iatfirst,AAA,BBB,CCC
I have done a diligent search on stackoverflow and none of my solution's seem to work. I know that I have to make the change while the looping is going on. However none of the examples I have seen have worked. Any further understanding or techniques to achieve my goal would be helpful. Whatever I am missing is probably very small. Please help.
String folderPath1 = "C:\\PayrollSync\\client\\client_orginal.txt";
File file = new File (folderPath1);
ArrayList<String> fileContents = new ArrayList<>(); // holds all matching client names in array
try {
BufferedReader reader = new BufferedReader(new FileReader(file));// reads entire file
String line;
while (( line = reader.readLine()) != null) {
if(line.contains("fooa")||line.contains("foob")){
fileContents.add(line);
}
//---------------------------------------
}
reader.close();// close reader
} catch (Exception e) {
System.out.println(e.getMessage());
}
System.out.println(fileContents);

Add a Line Feed before you add to fileContents.
fileContents.add(line+"\n");

By printing the list directly as you are doing you are invoking the method toString() overridden for the list which prints the contents like this:
obj1.toString(),obj2.toString() .. , objN.toString()
in your case the obj* are of type String and the toString() override for it returns the string itself. That's why you are seeing all the strings separated by comma.
To do something different, i.e: printing each object in a separate line you should implement it yourself, and you can simply append the new line character('\n') after each string.
Possible solution in java 8:
String result = fileContents.stream().collect(Collectors.joining('\n'));
System.out.println(result);

A platform-independent way to add a new line:
fileContents.add(line + System.lineSeparator);

Below is my full answer. Thanks for your help stackoverflow. It took me all day but I have a full solution.
File file = new File (folderPath1);
ArrayList<String> fileContents = new ArrayList<>(); // holds all matching client names in array
try {
BufferedReader reader = new BufferedReader(new FileReader(file));// reads entire file
String line;
while (( line = reader.readLine()) != null) {
String [] names ={"iatdaily","iatrapala","iatfirst","wpolkrate","iatjohnson","iatvaleant"};
if (Stream.of(names).anyMatch(line.trim()::contains)) {
System.out.println(line);
fileContents.add(line + "\n");
}
}
System.out.println("---------------");
reader.close();// close reader
} catch (Exception e) {
System.out.println(e.getMessage());
}

Parsed strings from .csv-file are invalid tokens in an kml-file. How can i solve this?

I have a code which parses strings from an CSV.-file (with twitter data) and gives them to a new KML file. When i parse the comments from the twitter data there are of course unknown tokens like: 🚨. When i open up the new KML-File in Google Earth i get an error because of this unknown tokens.
Question:
When i parse the strings, can i tell java it should throw out all unknown tokens from the string so that i don't have any unknown tokens in my KML?
Thank you
Code below:
String csvFile = "twitter.csv";
BufferedReader br = null;
String line = "";
String cvsSplitBy = ";";
String[] twitter = null;
int row_desired = 0;
int row_counter = 0;
String[] placemarks = new String[1165];
// ab hier einlesen der CSV
try {
br = new BufferedReader(new FileReader(csvFile));
while ((line = br.readLine()) != null) {
if (row_counter++ == row_desired) {
twitter = line.split(cvsSplitBy);
placemarks[row_counter] =
"<Placemark>\n"+
"<name>User ID: "+twitter[7]+"</name>\n"+
"<description>This User wrote: "+twitter[5]+" at the: "+twitter[6]+"</description>\n"+
"<Point>\n"+
"<coordinates>"+twitter[1]+","+twitter[2]+"</coordinates>\n"+
"</Point>\n"+
"</Placemark>\n";
row_desired++;
}
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
if (br != null) {
try {
br.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
for(int i = 2; i <= 1164;i++){
String kml2 = kml.concat(""+placemarks[i]+"");
kml=kml2;
}
kml = kml.concat("</Document></kml>");
FileWriter fileWriter = new FileWriter(filepath);
fileWriter.write(kml);
fileWriter.close();
Runtime.getRuntime().exec(googlefilepath + filepath);
}

Text files are not all built equal: you must always consider what character encoding is in use. I'm not sure about Twitter's data specifically, but I would guess they're doing like the rest of the world and using UTF-8.
Basically, avoid FileReader and instead use the constructor of InputStreamReader which lets you specify the Charset.
Tip: if you're using Java 7+, try this:
for (String line : Files.readAllLines(file.toPath(), Charset.forName("UTF-8"))) { ...
More Info
The javadoc of FileReader states "The constructors of this class assume that the default character encoding"
You should avoid this class, always. Or at least for any data that might ever be transferred between computers. Even a program running on Windows "using the default charset" will assume UTF-8 when run from inside Eclipse, or ISO_8859_1 when running outside Eclipse! Such non-determinism from a class is not good.

JAVA: Getting the content of specific strings from text files

I have a text file like this:
text
text
text
.
.
#data
instances1
instances2
.
.
instancesN
I want to get the contents of this file from #data until the end of the file, how can I do?
I found this method of FileUtils (from apache commons-lang) class but it's usable only if I already know the line number.
String ln = FileUtils.readLines(new File("arff_file/"+results.get(0)))
.get(lineNumber);

Since you are using Apache Commons, you can do it in one line:
String contents = FileUtils.readFileToString(new File("arff_file/"+results.get(0)), "UTF-16").replaceAll("^.*?(?=#data)", "");
This works by
reading the whole file into a single String
using regex-based replaceAll() to remove (by replacing with a blank) everything up to, but not including, #data
The regex breakdown of ^.*?(?=#data) is:
^ start of input
.*? a reluctantly quantified wildcard
(?=#data) a positive (non-consuming) look ahead that asserts that the next input is #data
A reluctant quantifier could be important to use so it won't skip past the first #data, in case it appears more than once in the input.

try {
String file = "fileName";
BufferedReader br = new BufferedReader(new FileReader(file));
String line;
while ((line = br.readLine()) != null) {
if (line.equals("#data"))
nowRead(br);//I just do this for more efficiency, you can set a boolean flag instead
}
br.close();
}catch (IOException e) {
//OMG Exception again!
}
}
static ArrayList<String> nowRead(BufferedReader br) throws IOException {
ArrayList<String> s = new ArrayList<String>();// do it as you wish
String line;
while ((line = br.readLine()) != null) {
s.add(line);
}
return s;
}

Path start = Paths.get("test.txt");
try
{
List<String> lines = Files.readAllLines(start);
for (Iterator<String> it = lines.iterator(); it.hasNext();)
{
String line = it.next();
if (!"#data".equals(line.trim()))
{
it.remove();
}
else
{
break;
}
}
System.out.println(lines);
}
catch (IOException e)
{
e.printStackTrace();
}
I was reading about Path online so why not something like this as alternative to Bohemian code?
Maybe something could be done using stream() of Java 8 but not still nothing...

Reading from InflaterInputStream and parsing the result

I am quite new to java, just started yesterday. Since I am a big fan of learning by doing, I am making a small project with it. But I am stucked in this part. I have written a file using this function:
public static boolean writeZippedFile(File destFile, byte[] input) {
try {
// create file if doesn't exist part was here
try (OutputStream out = new DeflaterOutputStream(new FileOutputStream(destFile))) {
out.write(input);
}
return true;
} catch (IOException e) {
// error handlind was here
}
}
Now that I have successully wrote a compressed file using above method, I want to read it back to console. First I need to be able to read the decompressed content and write string representaion of that content to console. However, I have a second problem that I don't want to write characters up to first \0 null character. Here is how I attempt to read the compressed file:
try (InputStream is = new InflaterInputStream(new FileInputStream(destFile))) {
}
and I am completely stuck here. Question is, how to discard first few character until '\0' and then write the rest of the decompressed file to console.

I understand that your data contain text since you want to print a string respresentation. I further assume that the text contains unicode characters. If this is true, then your console should also support unicode for the characters to be displayed correctly.
So you should first read the data byte by byte until you encounter the \0 character and then you can use a BufferedReader to print the rest of the data as lines of text.
try (InputStream is = new InflaterInputStream(new FileInputStream(destFile))) {
// read the stream a single byte each time until we encounter '\0'
int aByte = 0;
while ((aByte = is.read()) != -1) {
if (aByte == '\0') {
break;
}
}
// from now on we want to print the data
BufferedReader b = new BufferedReader(new InputStreamReader(is, "UTF8"));
String line = null;
while ((line = b.readLine()) != null) {
System.out.println(line);
}
b.close();
} catch(IOException e) { // handle }

Skip the first few characters using InputStream#read()
while (is.read() != '\0');

BufferedReader method ReadLine() is converting en-dash ("\u2013") to hyphen ("\u002D")

I have folders in a repository in SVN which have an en-dash ("\u2013") in their names.
I am first calling the "svn list" (in my Windows 7 + UTF-8 encoding) to get the list of the directory.
After that calling BufferedReader readLine(), it reads the text of the list.
The name of the folders being displayed contain a hyphen ("\u002D") instead of the en-dash ("\u2013").
Are there any limitations regarding that ?
class Test {
public static void main(String args[]) {
BufferedReader br = null;
try {
String sCurrentLine;
br = new BufferedReader(new FileReader("C:\\test–ing.xml"));
System.out.println(br.readLine());
while ((sCurrentLine = br.readLine()) != null) {
System.out.println(sCurrentLine);
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (br != null)
br.close();
} catch (IOException ex) {
ex.printStackTrace();
}
}
} // end main

This is probably the problem:
br = new BufferedReader(new FileReader("C:\\test–ing.xml"));
That will use the platform default encoding. You've said that the file is UTF-8-encoded - so you need to specify that you want UTF-8, which means avoiding FileReader's broken API:
br = new BufferedReader(new InputStreamReader(
new FileInputStream("C:\\test–ing.xml"), "UTF-8"));
That's assuming the file really is valid UTF-8 containing the expected character. You should check that before doing anything else.
Alternatively, given that this is XML, I assume in your real code you're going to use it as XML? If so, I would just load it straight from an input stream, and let the XML parser handle the encoding.