Develop Reference

Append a string in front of line in java?

I am creating a pattern lock based project in android.
I have a file called category.txt
The content of the file is as below
Sports:Race:Arcade:
No what i want is that whenever the user draw a pattern for a specific games category the pattern should get append in front of that category.
eg :
Sports:Race:"string/pattern string to be appended here for race"Arcade:
i have used following code but it is not working.
private void writefile(String getpattern,String category)
{
String str1;
try {
file = new RandomAccessFile(filewrite, "rw");
while((str1 = file.readLine()) != null)
{
String line[] = str1.split(":");
if(line[0].toLowerCase().equals(category.toLowerCase()))
{
String colon=":";
file.write(category.getBytes());
file.write(colon.getBytes());
file.write(getpattern.getBytes());
file.close();
Toast.makeText(getActivity(),"In Writefile",Toast.LENGTH_LONG).show();
}
}
}
catch (FileNotFoundException e)
{
e.printStackTrace();
}
catch(IOException io)
{
io.printStackTrace();
}
}
please help !

Using RandomAccessFile you have to calculate the position. I think it's much easier to just replace the file content with a little help from apache-commons-io FileUtils. This might be not the best idea if you have a very large file but it's quite simple.
String givenCategory = "Sports";
String pattern = "stringToAppend";
final String colon = ":";
try {
List<String> lines = FileUtils.readLines(new File("someFile.txt"));
String modifiedLine = null;
int index = 0;
for (String line : lines) {
String[] categoryFromLine = line.split(colon);
if (givenCategory.equalsIgnoreCase(categoryFromLine[0])) {
modifiedLine = new StringBuilder().append(pattern).append(colon).append(givenCategory).append(colon).toString();
break;
}
index++;
}
if (modifiedLine != null) {
lines.set(index, modifiedLine);
FileUtils.writeLines(new File("someFile.txt"), lines);
}
} catch (IOException e1) {
// do something
}

Gdx.files.internal(...) wrapper not working correctly

I made a wrapper ConfigurationFile class to help handle Gdx.files stuff, and it worked fine for a long time, but now it's not working, and I don't know why.
I have two of the following two methods: internal(...) and local(...). The only difference between the two is handling the load from arguments from (File folder, String name) and (String path).
-Snip Now Unnecessary Information-
UPDATE
After more configuring, I came to find out that they're not behaving the same. I have an assets/files/ folder that Gdx.files.internal(...) will access fine, but ConfigurationFile.internal(...) will access files/, and they're set up the same way. I'll give you the two pieces of code that I used for testing.
Using Gdx.files.internal(...) directly (works as expected):
FileHandle handle = Gdx.files.internal("files/virus_data");
BufferedReader reader = null;
try {
reader = new BufferedReader(handle.reader());
String c = "";
while ((c = reader.readLine()) != null) {
System.out.println(c); // prints out all 5 lines on the file.
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (reader != null) reader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
Using ConfigurationFile.internal(...):
// First part, calls ConfigurationFile#internal(String path)
ConfigurationFile config = ConfigurationFile.internal("files/virus_data");
// ConfigurationFile#internal(String path)
public static ConfigurationFile internal(String path) {
ConfigurationFile config = new ConfigurationFile();
// This is literally calling Gdx.files.internal("files/virus_data");
config.handle = Gdx.files.internal(path);
config.file = config.handle.file();
config.folder = config.file.getParentFile();
config.init();
return config;
}
// ConfigurationFile#init()
protected void init() {
// File not found.
// Creates a new folder as a sibling of "assets"
// Creates a new file called "virus_data"
if (!folder.exists()) folder.mkdirs();
if (!file.exists()) {
try {
file.createNewFile();
} catch (IOException e) {
e.printStackTrace();
}
} else loadFile();
}
// ConfigurationFile#loadFile()
protected void loadFile() {
BufferedReader reader = null;
try {
reader = new BufferedReader(handle.reader());
String c = "";
while ((c = reader.readLine()) != null) {
System.out.println(c);
if (!c.contains(":")) continue;
String[] values = c.split(":");
String key = values[0];
String value = values[1];
if (values.length > 2) {
for (int i = 2; i < values.length; i++) {
value += ":" + values[i];
}
}
key = key.trim();
value = value.trim();
mapValues.put(key, value);
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (reader != null) reader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
What I'm having trouble understanding is what's the difference between these two ways that it is causing my ConfigurationFile to create a new File in a folder that is a sibling of assets. Could someone tell me why this is happening?

My suggestion is not to use
Gdx.files.internal(folder + "/" + name);
If you have to use the File api, do it this way:
Gdx.files.internal(new File(folder, name).toString());
This way you avoid weird things that could be happening with path separators.
If Gdx maybe needs relative paths for some reason (perhaps relative to some Gdx internal home directory), you could use NIO to do something like
final Path gdxHome = Paths.get("path/to/gdx/home");
//...
File combined = new File(folder, name);
String relativePath = gdxHome.relativize(combined.toPath()).toString();

Okay, so after intense testing, I found out the problem, which I found to be ridiculous.
Since the file is Internal, that means a new File(...) reference can't be properly made to it, but instead it's an InputStream (if I'm correct), but anyways, using the method FileHandle#file() on an Internal file causes some kind of conversion for the path, so after removing anything that dealed with FileHandle#file() for an Internal file fixed it.

How to use java program to run command prompt commands?

this is my first time posting here, so I'm not really sure what to say/ask.
Anyways, I am trying to make a simple java program that runs command prompt commands from the java program, mainly used for ping flood (ping flooding myself).
Here is my current code
public class Core extends JFrame {
JTextField ipTextField;
int packets = 0;
boolean running = false;
public Core() {
super("Fatique");
Container container = getContentPane();
JButton bAttack = new JButton("Start Attack");
JButton bStop = new JButton("Stop Attack");
JPanel jPanel = new JPanel();
container.setLayout(new FlowLayout());
ipTextField = new JTextField("IP Address", 30);
container.add(ipTextField);
bAttack.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
String input = ipTextField.getText();
String[] value = input.split(":");
int amountOfPackets = Integer.parseInt(value[1]);
exec("cmd /c" + input + " -t -n " + amountOfPackets);
running = true;
}
});
bStop.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
stop();
}
});
if(!running) {
jPanel.add(bAttack);
} else {
jPanel.add(bStop);
}
add(jPanel);
}
public void exec(String cmd) {
try {
Process p = Runtime.getRuntime().exec(cmd);
System.out.println(getOutput(p) + " - " + getPacketsSent());
} catch (IOException e) {
e.printStackTrace();
}
}
public String getOutput(Process p) {
String output = null;
try {
BufferedReader in = new BufferedReader(new InputStreamReader(p.getInputStream()));
String line = null;
while ((line = in.readLine()) != null) {
output = line;
packets++;
}
return output;
} catch (IOException e) {
System.err.println(e.getStackTrace());
}
return null;
}
public int getPacketsSent() {
return packets;
}
public void stop() {
exec("cmd /c break");
running = false;
}
public static void main(String[] args) {
Core c = new Core();
c.setSize(500, 300);
c.setVisible(true);
c.setResizable(false);
c.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
c.setLocationRelativeTo(null);
}
I'm quite new at java, so that might not do what I want it to do.
What I want it to do is I enter an ip address in the textfield, and split it with ":", and after that the amount of packets, for instance
127.0.0.1:100
Though now when I try to use that ip and packet amount, it returns "null - 0" (from exec method), and I'm not even sure if it did anything related to ping.
What I am trying to accomplish is as I already said, ping flood myself, and then output whatever I get as response, though I have no idea if this code does anything even related to that, I mostly use logic when coding java.
public String getOutput(Process p) {
String output = null;
try {
BufferedReader in = new BufferedReader(new InputStreamReader(p.getInputStream()));
String line = null;
while ((line = in.readLine()) != null) {
output = line;
packets++;
}
return output;
} catch (IOException e) {
System.err.println(e.getStackTrace());
}
return null;
}
Could someone explain me why my code code is not working how I want it to work? Please don't judge, as I already said, I'm quite new to java programming.
EDIT: Here is a quick "informative" explanation of what I am trying to accomplish.
I type in an ip address and how many packets I want to send. In this explanation, I am using localhost ip, and 5 packets.
I start the attack. At this part, I want the program to run cmd prompt command
ping 127.0.0.1 -t -n 5
127.0.0.1 being the ip that I put in the textfield in my program, and 5 is the amount of packets I put in the textfield.
I started the attack, so this is what should happen in the command prompt:
The language is Finnish, but still the same thing.
This is the basic explanation of what I am trying to accomplish, hopefully someone understood and can help/tell why my code is not working, or is working but not printing the proper lines in eclipse console.

There is a problem with your getOutput method. It looks like you intend to collect every line of output. But in fact, since you are assigning line to output, you will only return the last line before the end of stream.
To fix this, change
output = line;
to
output += line + "\n";
Or to be more correct:
output += line + LINE_SEPARATOR;
where you previously declared the latter as:
final String LINE_SEPARATOR = System.getProperty("line.separator");
That doesn't directly explain why you are getting null, but that might be because the command you are running is writing output to the 'error' stream rather than the 'output' stream.

Try something like this:
try {
Runtime rt = Runtime.getRuntime();
Process p = rt.exec("ping 192.168.16.67");
InputStream in = p.getInputStream();
OutputStream out = p.getOutputStream ();
InputStream err = p.getErrorStream();
p.destroy();
} catch(Exception exc) {}
Then, you'll have to read the out variable to parse the ping command output continuously.

bAttack.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
String input = ipTextField.getText();
String[] value = input.split(":");
int amountOfPackets = Integer.parseInt(value[1]);
try {
p=Runtime.getRuntime().exec("ping -n "+amountOfPackets+" "+value[0]);
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
running = true;
}
Just a small modification of your code. get output is as:
public String getOutput(Process p) {
String output = null;
try {
BufferedReader in = new BufferedReader(new InputStreamReader(p.getInputStream()));
String line = null;
while ((line = in.readLine()) != null) {
output =output+ line+"\n";
packets++;
}
return output;
} catch (IOException e) {
System.err.println(e.getStackTrace());
}
return null;
}
Here output is JTextArea I have taken to display the output of PING process. I cannot show you the output because I lack reputation.
I don't know why first line is null. Anyway, it works.
Hope this help you. Have good time coding.

I need to contain all matches of a Regex into a text file; I'm new to java programming

I'm trying to contain all matches found into a text document, I have been banging my head on my desk for the past 3 hours and figured it would be time I asked for help.
My current issue is with the List<String> and I'm not sure if it because the information entered is wrong or if it's my file print methods. It does not print to file and with other means of printing such as writer.println(returnvalue) and even then, it still only displays one of the matches and not all, I do have the matches appearing in console just to make sure they are showing and they are.
Edit2: Sorry this would be my first question on stackoverflow, I guess my question is How would you print all the data from a list array to a text file?
Edit3: My newest problem is printing out all matches i am currently stuck printing out the last match, any advice?
public static void RegexChecker(String TheRegex, String line){
String Result= "";
List<String> returnvalue = new ArrayList<String>();
Pattern checkRegex = Pattern.compile(TheRegex);
Matcher regexMatcher = checkRegex.matcher(line);
int count = 0 ;
FileWriter writer = null;
try {
writer = new FileWriter("output.txt");
} catch (IOException e1) {
e1.printStackTrace();
}
while ( regexMatcher.find() ){
if (regexMatcher.group().length() != 0){
returnvalue.add(regexMatcher.group());
System.out.println( regexMatcher.group().trim() );
}
for(String str: returnvalue) {
try {
out.write(String.valueOf(returnvalue.get(i)));
writer.write(str);
} catch (IOException e) {
e.printStackTrace();
}
}
}
}

Get the for out of while. You want to write to the file only after all matches have been added to the list. The for-each block needs some modifications as well.
The for-each construct gives you values from iteration over the collection. You need not obtain the values again using an index.
Try this:
while (regexMatcher.find()) {
if (regexMatcher.group().length() != 0) {
returnvalue.add(regexMatcher.group());
System.out.println(regexMatcher.group().trim());
}
}
try {
for (String str : returnvalue) {
writer.write(str + "\n");
}
writer.flush();
writer.close();
} catch (IOException e) {
e.printStackTrace();
}

String comparison issue

I'm trying to do something reallllly simple that apparently is extremely difficult in android.
I just want to compare two strings to see if they are equal.
I have a temp variable with the value "Location"
I have debugged this and it does indeed contain Location...
So I tried this at first
if(temp == "Location") { //do something }
But I already know that doesn't work. I then tried all the possible functions for a string such as:
.equals
.contains
.ignoreCaseEquals
etc...
If anyone has any idea what to do please help. This is really getting annoying.
EDIT:
Here is the function where I'm comparing the strings for those of you who want to see.
public String[] getData(){
try {
int tempGroupCount = 0;
URL food_url = new URL (Constants.SERVER_DINING);
BufferedReader my_buffer = new BufferedReader(new InputStreamReader(food_url.openStream()));
temp = my_buffer.readLine();
// prime read
while (temp != null ){
// check to see if readline equals Location
Log.w("HERasdfsafdsafdsafE", temp);
// start a new location
if (temp.equals("Location")
{
groups[tempGroupCount] = temp;
tempGroupCount++;
}
Log.w("HERasdfsafdsafdsafE", temp);
//start for-loop to test to get child info
//for(temp = my_buffer.readLine(); temp != "Location" && temp != null; groupCount++, childrenCount++){
//children[groupCount][childrenCount] = temp;
//}
temp = my_buffer.readLine();
}
my_buffer.close();
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
Log.e("IO EXCEPTION", "Exception occured in MyExpandableListAdapter:" + e.toString());
}
return groups;
}

equals does work. If temp.equals("Location") returns false, then your temp variable does not refer to a string with the value "Location".
There may be unprintable characters or other oddities about the string - I suggest you look at the length of the string to check. Alternatively, there can be other characters which look like the ASCII characters, but aren't. In the debugger, try examining the array and get at the underlying char array - check the Unicode value of each character.

if(temp.equals("Location"))
{
//your code here
}
does not work
try this
if(temp.contains("Location"))
{
//your code here
}

try like
if(temp.equals("Location")) { //do something }
and
while (!temp.equals("")){

if your variable temp is a String, you can also used the method compareTo(String).
if (temp.compareTo("Location") == 0)
{
//do something
}

I am doing same scenario , its working fine.
String result = responsePrimitiveData.toString();
if(!result.equals("0")){
}

Try doing this:
if (temp.toLowerCase().compareTo("location") == 0)

public String[] getData(){
try {
int tempGroupCount = 0;
URL food_url = new URL (Constants.SERVER_DINING);
BufferedReader my_buffer = new BufferedReader(new InputStreamReader(food_url.openStream()));
temp = my_buffer.readLine();
// prime read
while (temp != null ){
// check to see if readline equals Location
Log.w("HERasdfsafdsafdsafE", temp);
// start a new location
if (temp.toString().equalsIgnoreCase("Location")
{
groups[tempGroupCount] = temp;
tempGroupCount++;
}
Log.w("HERasdfsafdsafdsafE", temp);
//start for-loop to test to get child info
//for(temp = my_buffer.readLine(); temp != "Location" && temp != null; groupCount++, childrenCount++){
//children[groupCount][childrenCount] = temp;
//}
temp = my_buffer.readLine();
}
my_buffer.close();
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
Log.e("IO EXCEPTION", "Exception occured in MyExpandableListAdapter:" + e.toString());
}
return groups;
}
first try to convert "temp" into string then compare it, apply this may helps you

you may try the following to find out where your problem is.
final String LOCATION = "Location"; // just to make sure we use the very same character sequence
if (temp.equals(LOCATION)
{
/* your code here */
}
else
{
System.out.println("Location : " + Arrays.toString(LOCATION.getBytes(Charset.forName("UTF-8"))));
System.out.println("temp : " + Arrays.toString(temp.getBytes(Charset.forName("UTF-8"))));
}
This should print the byte representation of both Strings to standard out. If equals() returns false, the strings differ. Because of unprintable characters or similar looking characters it's sometimes difficult to find the difference. But the byte representation should show you.
(I'm not an android programmer, so I hope the functions exist on android JVM. And sorry for any typos and missing brackets - if any ;-)