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How to read content from a text zip file?

This prints everything one one line. My original text file has different lines. How to still get the content line by line after the file is zipped? I am working on Mac.
public static void main(String[] args) throws IOException {
QuickTest mfe = new QuickTest();
ZipFile zip = new ZipFile("test.txt.zip");
for (Enumeration e = zip.entries(); e.hasMoreElements(); ) {
ZipEntry entry = (ZipEntry) e.nextElement();
System.out.println(entry.getName());
if (!entry.isDirectory()) {
if (FilenameUtils.getExtension(entry.getName()).equals("txt")) {
StringBuilder out = getTxtFiles(zip.getInputStream(entry));
System.out.println(out.toString());
}
}
}
System.out.println("Done");
}
private static StringBuilder getTxtFiles(InputStream in) {
StringBuilder out = new StringBuilder();
BufferedReader reader = new BufferedReader(new InputStreamReader(in));
String line;
try {
while ((line = reader.readLine()) != null) {
out.append(line);
}
} catch (IOException e) {
// do something, probably not a text file
e.printStackTrace();
}
return out;
}

Inside your method:
private static StringBuilder getTxtFiles(InputStream in) {
StringBuilder out = new StringBuilder();
BufferedReader reader = new BufferedReader(new InputStreamReader(in));
String line;
The following loop:
try {
while ((line = reader.readLine()) != null) {
out.append(line);
}
reads lines but the Java readLine() method does not append an end-of-line character. You'll need to add a newline (or carriage return for the Mac) to see lines.
try {
while ((line = reader.readLine()) != null) {
out.append(line);
out.append( '\n' );
}

How to display all lines of text from a file instead of stopping at the end of a line?

The code below only brings up the first line of code and stops. I would like to return each line of code until there are no more.
private String GetPhoneAddress() {
File directory = Environment.getExternalStorageDirectory();
File myFile = new File(directory, "mythoughtlog.txt");
//File file = new File(Environment.getExternalStorageDirectory() + "mythoughtlog.txt");
if (!myFile.exists()){
String line = "Need to add smth";
return line;
}
String line = null;
//Read text from file
//StringBuilder text = new StringBuilder();
try {
BufferedReader br = new BufferedReader(new FileReader(myFile));
line = br.readLine();
}
catch (IOException e) {
//You'll need to add proper error handling here
}
return line;
}

You could loop over the results of readLine() and accumulate them until you get a null, indicating the end of the file (BTW, note that your snippet neglected to close the reader. A try-with-resource structure could handle that):
try (BufferedReader br = new BufferedReader(new FileReader(myFile))) {
String line = br.readLine();
if (line == null) {
return null;
}
StringBuilder retVal = new StringBuilder(line);
line = br.readLine();
while (line != null) {
retVal.append(System.lineSeparator()).append(line);
line = br.readLine();
}
return retVal.toString();
}
if you're using Java 8, you can save a lot of this boiler-plated code with the newly introduced lines() method:
try (BufferedReader br = new BufferedReader(new FileReader(myFile))) {
return br.lines().collect(Collectors.joining(System.lineSeparator()));
}

A considerably less verbose solution:
try (BufferedReader br = new BufferedReader(new FileReader(myFile))) {
StringBuilder retVal = new StringBuilder();
while ((line = br.readLine()) != null) {
retVal.append(line).append(System.lineSeparator());
}
return retVal.toString();
}

How to create item objects from reading a text file?

I'm trying to read data from a text file and create Item Objects with it.
Item Objects have fields String title, String formatt, boolean onLoan, String loanedTo and String dateLoaned. In my save()method, I print every object to a text file in a new line and the fields are seperated by "$" (dollar sign). How can I read the text file line by line and create a new object from each line and add it to an array.
TextFile Example:
StarWars$DVD$false$null$null
Aliens$Bluray$true$John$Monday
public void save() {
String[] array2 = listForSave();
PrintWriter printer = null;
try {
printer = new PrintWriter(file);
for (String o : array2) {
printer.println(o);
}
printer.close();
} catch ( IOException e ) {
e.printStackTrace();
}
}
public void open(){
try{
FileReader fileReader = new FileReader(file);
BufferedReader bufferedReader = new BufferedReader(fileReader);
StringBuffer stringBuffer = new StringBuffer();
String line;
while ((line = bufferedReader.readLine()) != null) {
stringBuffer.append(line);
stringBuffer.append("\n");
}
fileReader.close();
System.out.println("Contents of file:");
System.out.println(stringBuffer.toString());
}catch ( IOException e ) {
e.printStackTrace();
}
}
Thanks everyone. Here's my final code:
public void open(){
try{
FileReader fileReader = new FileReader(file);
BufferedReader bufferedReader = new BufferedReader(fileReader);
String line;
String[] strings;
while ((line = bufferedReader.readLine()) != null) {
strings = line.split("\\$");
String title = strings[0];
String format = strings[1];
boolean onLoan = Boolean.parseBoolean(strings[2]);
String loanedTo = strings[3];
String dateLoaned = strings[4];
MediaItem superItem = new MediaItem(title,format, onLoan,loanedTo,dateLoaned);
items.add(superItem);
}
fileReader.close();
}catch ( IOException e ) {
e.printStackTrace();
}
}

String line = // input line e.g. "Aliens$Bluray$true$John$Monday"
String[] strings = line.split("\\$"); // use regex matching "$" to split
String title = strings[0];
String formatt = strings[1];
boolean onLoan = Boolean.parseBoolean(strings[2]);
String loanedTo = strings[3];
String dateLoaned = strings[4];
// TODO: create object from those values
Maybe you need to handle null differently (in case you want the String "null" to be converted to null); note that you can't distinguish if null or "null" was saved.
This function converts "null" to null and returns the same string otherwise:
String convert(String s) {
return s.equals("null") ? null : s;
}
Reading the objects to an array
Since you don't know the number of elements before reading all lines, you have to work around that:
Write the number of objects in the file as first line, which would allow you to create the array before reading the first object. (Use Integer.parseInt(String) to convert the first line to int):
public void save() {
String[] array2 = listForSave();
PrintWriter printer = null;
try {
printer = new PrintWriter(file);
printer.println(array2.length);
for (String o : array2) {
printer.println(o);
}
printer.close();
} catch ( IOException e ) {
e.printStackTrace();
}
}
public void open(){
try{
FileReader fileReader = new FileReader(file);
BufferedReader bufferedReader = new BufferedReader(fileReader);
StringBuffer stringBuffer = new StringBuffer();
int arraySize = Integer.parseInt(stringBuffer.readLine());
Object[] array = new Object[arraySize];
int index = 0;
String line;
while ((line = bufferedReader.readLine()) != null) {
// split line and create Object (see above)
Object o = // ...
array[index++] = o;
}
//...
}catch ( IOException e ) {
e.printStackTrace();
}
//...
}
or
Use a Collection, e.g. ArrayList to store the objects and use List.toArray(T[]) to get an array.

quick and dirty solution might be...
public void open(){
try{
ArrayList<Item> list = new ArrayList<Item>(); //Array of your ItemObject
FileReader fileReader = new FileReader(file);
BufferedReader bufferedReader = new BufferedReader(fileReader);
StringBuffer stringBuffer = new StringBuffer();
String line;
while ((line = bufferedReader.readLine()) != null) {
Item itm = new Item(); //New Item Object
String [] splitLine = line.split("\\$");
item.title = splitLine[0];
item.format = splitLine[1];
item.onLoan = Boolean.parseBoolean(splitLine[2]);
item.loanedTo = splitLine[3];
item.dateLoaned = splitLine[4];
list.add(itm);
stringBuffer.append(line);
stringBuffer.append("\n");
}
fileReader.close();
System.out.println("Contents of file:");
System.out.println(stringBuffer.toString());
}catch ( IOException e ) {
e.printStackTrace();
}
}
But this is won't scale if you need to re-arrange or add new fields.

You could try this to "parse" every line of your file
String[] result = "StarWars$DVD$false$null$null".split("\\$");
for (int i=0; i<result.length; i++) {
String field = result[i]
... put the strings in your object ...
}

Save content of File as String in Java?

I was working a little bit with config files and file reader classes in java.
I always read/wrote in the files with arrays because I was working with objects.
This looked a little bit like this:
public void loadUserData(ArrayList<User> arraylist) {
try {
List<String> lines = Files.readAllLines(path, Charset.defaultCharset());
for(String line : lines) {
String[] userParams = line.split(";");
String name = userParams[0];
String number= userParams[1];
String mail = userParams[2];
arraylist.add(new User(name, number, mail));
}
} catch (IOException e) {
e.printStackTrace();
}
}
This works fine, but how can I save the content of a file as only one single string?
When I read a file, the string I use should be the exact same as the content of the file (without the use of arrays or line splits).
how can I do that?
Edit:
I try to read a SQL-Statement out of a file to use it with JDBC later on. That's why I need the content of the File as a single String

This method will work
public static void readFromFile() throws Exception{
FileReader fIn = new FileReader("D:\\Test.txt");
BufferedReader br = new BufferedReader(fIn);
String line = null;
StringBuilder sb = new StringBuilder();
while ((line = br.readLine()) != null) {
sb.append(line);
sb.append("\n");
}
String text = sb.toString();
System.out.println(text);
}

I hope this is what you need:
public void loadUserData(ArrayList<User> arraylist) {
StringBuilder sb = new StringBuilder();
try {
List<String> lines = Files.readAllLines(path, Charset.defaultCharset());
for(String line : lines) {
// String[] userParams = line.split(";");
//String name = userParams[0];
//String number= userParams[1];
//String mail = userParams[2];
sb.append(line);
}
String jdbcString = sb.toString();
System.out.println("JDBC statements read from file: " + jdbcString );
} catch (IOException e) {
e.printStackTrace();
}
}
or maybe this:
String content = new Scanner(new File("filename")).useDelimiter("\\Z").next();
System.out.println(content);

Just do that:
final FileChannel fc;
final String theFullStuff;
try (
fc = FileChannel.open(path, StandardOpenOptions.READ);
) {
final ByteBuffer buf = ByteBuffer.allocate(fc.size());
fc.read(buf);
theFullStuff = new String(buf.array(), theCharset);
}
nio for the win! :p

You could always create a Buffered reader e.g.
File anInputFile = new File(/*input path*/);
FileReader aFileReader = new FileReader(anInputFile);
BufferedReader reader = new BufferedReader(aFileReader)
String yourSingleString = "";
String aLine = reader.readLine();
while(aLine != null)
{
singleString += aLine + " ";
aLine = reader.readLine();
}

Java Text Input: How to ignore lines starting with certain characters in them?

I basically want to ignore certain lines with characters in them, like if there's a line
// hello, i'm bill
I want to ignore that line while reading it because it contains the character "//". How can I do that? I tried method skip(), but it gives me errors.
public String[] OpenFile() throws IOException {
FileReader reader = new FileReader(path);
BufferedReader textReader = new BufferedReader(reader);
int numberOfLines = readLines();
String[] textData = new String[numberOfLines];
int i;
for (i=0; i<numberOfLines; i++) {
textData[i] = textReader.readLine();
}
// close the line-by-line reader and return the data
textReader.close();
return textData;
}
int readLines() throws IOException {
FileReader reader = new FileReader(path);
BufferedReader textReader = new BufferedReader(reader);
String line;
int numberOfLines = 0;
while ((line = textReader.readLine()) != null) {
// I tried this:
if (line.contains("//")) {
line.skip();
}
numberOfLines++;
}
reader.close();
return numberOfLines;
}
Update: HERE's MY MAIN METHOD:
try{
ReadFile files = new ReadFile(file.getPath());
String[] anyLines = files.OpenFile();
}

while ((line = textReader.readLine()) != null) {
// I tried this:
if (line.contains("//")) {
continue;
}
numberOfLines++;
}
note that continue might seem a bit goto like and be prone to critique
edit here's what you are after (note this doesn't need the countLines method)
public String[] OpenFile() throws IOException {
FileReader reader = new FileReader(path);
BufferedReader textReader = new BufferedReader(reader);
List<String> textData = new LinkedList<String>();//linked list to avoid realloc
String line;
while ((line = textReader.readLine()) != null) {
if (!line.contains("//")) textData.add(line);
}
// close the line-by-line reader and return the data
textReader.close();
return textData.toArray(new String[textData.size()]);
}

As Andrew Thompson points out, it would be best to read the file line by line into an ArrayList. Pseudo-Code:
For Each Line In File
If LineIsValid()
AddLineToArrayList()
Next
UPDATE to fix your actual code:
public String[] OpenFile() throws IOException {
FileReader reader = new FileReader(path);
BufferedReader textReader = new BufferedReader(reader);
int numberOfLines = readLines();
String[] textData = new String[numberOfLines];
int BufferIndex = 0;
String line;
while ((line = textReader.readLine()) != null) {
if (line.trim().startsWith("//")) {
// Don't inject current line into buffer
}else{
textData[BufferIndex] = textReader.readLine();
BufferIndex = BufferIndex + 1;
}
}
// close the line-by-line reader and return the data
textReader.close();
return textData;
}
In your ReadLines() Function:
while ((line = textReader.readLine()) != null) {
if (line.trim().startsWith("//")) {
// do nothing
}else{
numberOfLines++;
}
}
Basically, you're on the right track.
Note: You may be interested in the startsWith() string function