Develop Reference

Append zeros to input edit text to get minLength

I have edit text with minLength=13. If user enters below 13 characters I want to append the zeros in front of the input to make this length to 13. Ex: user enter 123 -> 0000000000123.
Any approach?

This can be done with String.format, provided the input is an integer:
int input = 123;
int pad_width = 13;
String padded = String.format("%0"+pad_width+"d", input);
// padded is now "0000000000123"
Answers related to this on other questions:
https://stackoverflow.com/a/4051905/940217
https://stackoverflow.com/a/391978/940217

The easiest way would be to check the length of the user's input.
String input = 123;
StringBuilder finalString= new StringBuilder();
for (int i=0; i<13-input.length(); i++){
finalString.append("0")
}
finalString.append(input)

Yea this is pretty easy. Keep in mind this code is not tested:
// Declaration
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Declare edittext here
mEditText = // init code...
}
// Detect when user has pressed done
public void setKeyListener() {
mEditText.setOnKeyListener(new View.OnKeyListener() {
#Override
public boolean onKey(View v, int keyCode, KeyEvent event) {
if (event.getAction() == KeyEvent.ACTION_DOWN) {
if (keyCode == KeyEvent.KEYCODE_ENTER) {
String s = mEditText.getText().toString();
s = appendZerosIfNecessary();
return true;
}
}
return false;
}
});
// Append if necessary
private String appendZerosIfNecessary(String s) {
int length = s.length;
if (s.length < 13) {
StringBuilder sb = new StringBuilder(s);
for (int i = length; i < 13; i++) {
sb.append('0');
}
return sb.toString();
}
return s;
}
Note this code is not tested, but you get the idea.
EDIT: just reread question you want 0's appended in the beginning.
In this case I would merge the other answer with this one and change appendZerosIfNecessary() to the following:
private String appendZerosIfNecessary(String s) {
StringBuilder finalString = new StringBuilder();
for (int i = 0; i < (13 - input.length()); i++){
finalString.append('0')
}
finalString.append(input)
}

Convert Hex String to String

HI I have to tried multiple ways to convert Hex String to ASCII String but not getting success. While before I have done the same but now I am not able to achieve it.
My Code is
private static String hexToASCII(String hexValue)
{
StringBuilder output = new StringBuilder("");
for (int i = 0; i < hexValue.length(); i += 2)
{
String str = hexValue.substring(i, i + 2);
output.append((char) Integer.parseInt(str, 16));
}
return output.toString();
}
but it is returning garbage value like b��¡
and my Hex String is
621c8002008a820101a10a8c0341c2009c0341c2008302010288008a0105
Please help me if someone has also suffered from the same issue and fixed it.
Thanks ....

Try this out
public class HextoAsscii {
public static void main(String args[])
{
String hex="621c8002008a820101a10a8c0341c2009c0341c2008302010288008a0105";
String str="";
str= hexToASCII(hex);
}
private static String hexToASCII(String hexValue)
{
StringBuilder output = new StringBuilder("");
for (int i = 0; i < hexValue.length(); i += 2)
{
if(i+2<=hexValue.length())
{
String str = hexValue.substring(i, i + 2);
output.append(Integer.parseInt(str, 16));
}
}
System.out.println(output.toString());
return output.toString();
}
}

Compare contents of two files line by line

public class MainActivity extends Activity {
FileOutputStream fos;
FileInputStream fOne, fTwo;
ArrayList<String> arr1 = new ArrayList<String>();
ArrayList<String> arr2 = new ArrayList<String>();
ArrayList<String> words = new ArrayList<String>();
ArrayList<String> wordsTwo = new ArrayList<String>();
int count = 0;
int countTwo = 0;
int countThree = 0;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button fileOne = (Button)findViewById(R.id.file1);
Button fileTwo = (Button)findViewById(R.id.file2);
Button compare = (Button)findViewById(R.id.compare);
arr1.add("1");
arr1.add("2");
arr1.add("3");
arr1.add("4");
//arr1.add("3");
arr2.add("1");
arr2.add("2");
fileOne.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
try
{
fos = openFileOutput("File1", Context.MODE_PRIVATE);
for(int temp = 0; temp< arr1.size(); temp++)
{
fos.write((arr1.get(temp).getBytes()) );
fos.write(System.getProperty("line.separator").getBytes());
}
fos.close();
fos.flush();
}
catch(Exception e)
{
}
}
});
fileTwo.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
try
{
fos = openFileOutput("File2", Context.MODE_PRIVATE);
for(int temp = 0; temp< arr2.size(); temp++)
{
fos.write((arr2.get(temp).getBytes()) );
fos.write(System.getProperty("line.separator").getBytes());
}
fos.close();
fos.flush();
}
catch(Exception e)
{
}
}
});
compare.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
try
{
fOne = openFileInput("File1");
fTwo = openFileInput("File2");
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Scanner scanFile = new Scanner(new DataInputStream(fOne));
Scanner scanFileT = new Scanner(new DataInputStream(fTwo));
words = new ArrayList<String>();
wordsTwo = new ArrayList<String>();
while (scanFile.hasNextLine())
{
if(scanFile.nextLine()!=null)
{
count++;
}
while(scanFileT.hasNextLine())
{
if(scanFileT.nextLine()!=null)
{
countTwo++;
}
}
}
try
{
fOne.close();
fTwo.close();
scanFile.close();
scanFileT.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Toast.makeText(getBaseContext(), "One : " + count, 1000).show();
Toast.makeText(getBaseContext(), "Two : " + countTwo, 1000).show();
Toast.makeText(getBaseContext(), "Three : " + countThree, 1000).show();
count = 0 ;
countTwo = 0;
countThree = 0;
}
});
}
}
Above is the code to write and read the file. What I did here, write two files and read the contents..Now I have to compare contents of files line by line. What needs to be done?

Try following code. This will give you desired output. I took files from asset directory. So you need to replace that line of code if you are taking files from other directory.
private void compareFiles() throws Exception {
String s1 = "";
String s2 = "", s3 = "", s4 = "";
String y = "", z = "";
// Reading the contents of the files
BufferedReader br = new BufferedReader(new InputStreamReader(
getAssets().open("first.txt")));
BufferedReader br1 = new BufferedReader(new InputStreamReader(
getAssets().open("second.txt")));
while ((z = br1.readLine()) != null) {
s3 += z;
s3 += System.getProperty("line.separator");
}
while ((y = br.readLine()) != null) {
s1 += y;
s1 += System.getProperty("line.separator");
}
// String tokenizing
StringTokenizer st = new StringTokenizer(s1);
String[] a = new String[10000];
for (int l = 0; l < 10000; l++) {
a[l] = "";
}
int i = 0;
while (st.hasMoreTokens()) {
s2 = st.nextToken();
a[i] = s2;
i++;
}
StringTokenizer st1 = new StringTokenizer(s3);
String[] b = new String[10000];
for (int k = 0; k < 10000; k++) {
b[k] = "";
}
int j = 0;
while (st1.hasMoreTokens()) {
s4 = st1.nextToken();
b[j] = s4;
j++;
}
// comparing the contents of the files and printing the differences, if
// any.
int x = 0;
for (int m = 0; m < a.length; m++) {
if (a[m].equals(b[m])) {
} else {
x++;
Log.d("Home", a[m] + " -- " + b[m]);
}
}
Log.d("Home", "No. of differences : " + x);
if (x > 0) {
Log.d("Home", "Files are not equal");
} else {
Log.d("Home", "Files are equal. No difference found");
}
}
Input File 1
Hi
Hello
Chintan
Rathod
Input File 2
Hi
HellO
Chintan
RathoD
Output
08-26 12:07:58.219: DEBUG/Home(2350): Hello3. -- HellO3.
08-26 12:07:58.219: DEBUG/Home(2350): Rathod -- RathoD
08-26 12:07:58.229: DEBUG/Home(2350): No. of differences : 2
08-26 12:07:58.229: DEBUG/Home(2350): Files are not equal
Edit
To get Difference between two files
Use StringUtils library which is provide by Apache and check this Documentation for more about that library.
And modify following lines of code.
int x = 0;
for (int m = 0; m < a.length; m++) {
if (a[m].equals(b[m])) {
} else {
x++;
Log.d("Home", a[m] + " -- " + b[m]);
//to print difference
if (a[m].length() < b[m].length())
Log.d("Home", "" + StringUtils.difference(a[m], b[m]));
else
Log.d("Home", "" + StringUtils.difference(b[m], a[m]));
}
}
Output
08-26 17:51:26.949: DEBUG/Home(17900): 12 -- 123
08-26 17:51:26.949: DEBUG/Home(17900): Difference String : 3
08-26 17:51:26.949: DEBUG/Home(17900): No. of differences : 1
08-26 17:51:26.949: DEBUG/Home(17900): Files are not equal

Try using java.util.Scanner
while (sc1.hasNext() && sc2.hasNext()) {
String str1 = sc1.next();
String str2 = sc2.next();
if (!str1.equals(str2))
System.out.println(str1 + " != " + str2);
}

Change your while loop to the following:
while (scanFile.hasNextLine() && scanFileT.hasNextLine())
{
if(scanFileT.nextLine().equals(scanFile.nextLine()))
{
// The lines are equal.
} else {
// The lines are not equal.
}
}
if(scanFile.hasNextLine() || scanFileT.hasNextLine())
{
// If more lines remain in one of the files, they are not equal.
} else {
// If no content remains in both files, they are equal.
}
Depending on the size of your file, I would recommend some optimisation like checking the file sizes before you go through them line by line.
The overall logic reads as follows; if both have another line, compare it to see if it is equal. If they don't have another line, check if one of them has lines remaining, if so, they are not equal.
Update
After clarifying the objective of the comparison in chat, see the comments to this question, I have come to the conclusion that another comparison would be more effective and, as a matter of fact, correct. The comparison algorithm above works great if comparing the structure of text but not if comparing a data vector which may or may not be sorted. After some discussion, we came to the conclusion that data needs to be sorted or the comparison will blow the complexity to at least O(n^2)which could be done in O(2n) if the data is sorted. Here the algorithm's skeleton:
if(! scanGroupFriends.hasNextLine())
{
//simple sanity check to see if we need to compare at all. In this case, add all friends.
} else {
String nextFriend = scanGroupFriends.nextLine();
while(scanAllFriends.hasNextLine())
{
if(scanAllFriends.nextLine().equals(nextFriend))
{
// Friend already figures, do not add him and advance the list of group friends.
if(scanGroupFriends.hasNextLine())
{
nextFriend = scanGroupFriends.nextLine();
} else {
// There are no more friends in the group, add all remaining friends to list to show.
break; // Terminate the `while` loop.
}
}
}
}
However, I personally think it is bad to make to many assumptions. What I would suggest is that the friends be saved in a Set, a TreeSet for example. Then, serialize the object rather than manually writing it to file. Sets are neat because they hold several interesting objects. For example, you could easily use the following code to remove all friends in a group from the set of all friends:
allFriends.removeAll(groupFriends);
However, be aware that this removes it from the set completely so you should make a copy beforehand.

Android CSV parser problem

I am having an issue while parsing a CSV file. It is only 2 rows of data with a comma separating them. Row one is a date and row 2 is a value. The date field will always have dates in it but sometimes the value is blank (or null?). When it gets to the null value I get a StringIndexOutOfBoundsException and the app crashes. I am logging each loop and can see the data but as soon as I get to a null value it stops looping and gives the error. If there are no null values then it works perfect. Here is my code:
BufferedReader buf = new BufferedReader(new StringReader(file));
String line = null;
while ((line = buf.readLine()) != null) {
try {
String date = null, value = null;
String[] RowData = line.split(",");
date = RowData[0];
value = RowData[1]; (this is the row it crashes on)
This is what the CSV looks like:
2011-08-28 09:16,8.23
2011-08-28 09:15,8.24
2011-08-28 09:14,8.26
2011-08-28 09:13,8.34
2011-08-28 09:12,
2011-08-28 09:11,10.72
2011-08-28 09:10,
2011-08-28 09:09,
the value at 09:13 is the last thing in logcat before I get the error.
This fixed it:
if(RowData.length == 2) {
date = RowData[0];
value = RowData[1];
} else {
date = RowData[0];
value = "0";
}
I wrote a 0 in the value field so later processes will not choke on the null value. Thanks for all your help guys!

You want to do this or something like it:
String date = null, value = null;
String[] RowData = line.split(",");
date = RowData[0];
if(RowData.length ==2)value = RowData[1]; (this is the row it crashes on)
Or some variation of it e.g. if(RowData.length < 2) dont attempt to read the value. Its a pretty standard thing - if you ask an array for an index of a value it doesn't have Java will crash.

Why write your own CSV parsing when you could use a library that has already been written which will do it for you? Perhaps OpenCSV would help you achieve your CSV parsing goal.

Check the length of RowData before you try to access it. It looks like split() is returning an array with a single object but you're trying to access the second object, which is indeed out of bounds.

public class CityParser {
DocumentBuilderFactory factory;
DocumentBuilder builder;
Document doc;
Element ele;
int mediaThumbnailCount;`enter code here`
boolean urlflag;
CityListBean objBean = null;
Vector<CityListBean> vecCityList;
public CityParser() {
}
public Vector<CityListBean> getCityData() {
vecCityList = new Vector<CityListBean>();
try {
HttpClient httpClient = new DefaultHttpClient();
HttpContext localContext = new BasicHttpContext();
HttpGet httpGet = new HttpGet(
"http://heresmyparty.com/cms/index.php?option=com_chronocontact&chronoformname=add_event_form_download");
HttpResponse response = httpClient.execute(httpGet, localContext);
// String result = "";
BufferedReader reader = new BufferedReader(new InputStreamReader(
response.getEntity().getContent()));
CSVReader csvreader = new CSVReader(reader);
String[] nextLine;
while ((nextLine = csvreader.readNext()) != null) {
CityListBean objcitylist = new CityListBean();
// nextLine[] is an array of values from the line
objcitylist.setText_title(nextLine[5]);
objcitylist.setText_host(nextLine[6]);
objcitylist.setText_price(nextLine[7]);
objcitylist.setDate(nextLine[8]);
objcitylist.setText_venue(nextLine[11]);
objcitylist.setAddress(nextLine[12]);
objcitylist.setLatitude(nextLine[13]);
objcitylist.setLongitude(nextLine[14]);
objcitylist.setFile(nextLine[15]);
objcitylist.setText_description(nextLine[16]);
objcitylist.setCity(nextLine[17]);
vecCityList.addElement(objcitylist);
}
/*for (int i = 0; i < vecCityList.size(); i++) { CityListBean
objcity = (CityListBean) vecCityList.get(i);
System.out.println("Cf_id : " + objcity.getCityName());
System.out.println("-----------------------------------"); }*/
} catch (Exception ex) {
ex.printStackTrace();
}
return vecCityList;
}
}
==========================================================================================
public class CSVReader {
private BufferedReader br;
private boolean hasNext = true;
private char separator;
private char quotechar;
private int skipLines;
private boolean linesSkiped;
public static final char DEFAULT_SEPARATOR = ',';
public static final char DEFAULT_QUOTE_CHARACTER = '"';
public static final int DEFAULT_SKIP_LINES = 0;
public CSVReader(Reader reader) {
this(reader, DEFAULT_SEPARATOR, DEFAULT_QUOTE_CHARACTER,
DEFAULT_SKIP_LINES);
}
public CSVReader(Reader reader, char separator, char quotechar, int line) {
this.br = new BufferedReader(reader);
this.separator = separator;
this.quotechar = quotechar;
this.skipLines = line;
}
public String[] readNext() throws IOException {
String nextLine = getNextLine();
return hasNext ? parseLine(nextLine) : null;
}
private String getNextLine() throws IOException {
if (!this.linesSkiped) {
for (int i = 0; i < skipLines; i++) {
br.readLine();
}
this.linesSkiped = true;
}
String nextLine = br.readLine();
if (nextLine == null) {
hasNext = false;
}
return hasNext ? nextLine : null;
}
private String[] parseLine(String nextLine) throws IOException {
if (nextLine == null) {
return null;
}
List<String> tokensOnThisLine = new ArrayList<String>();
StringBuffer sb = new StringBuffer();
boolean inQuotes = false;
do {
if (inQuotes) {
// continuing a quoted section, reappend newline
sb.append("\n");
nextLine = getNextLine();
if (nextLine == null)
break;
}
for (int i = 0; i < nextLine.length(); i++) {
char c = nextLine.charAt(i);
if (c == quotechar) {
// this gets complex... the quote may end a quoted block, or escape another quote.
// do a 1-char lookahead:
if( inQuotes // we are in quotes, therefore there can be escaped quotes in here.
&& nextLine.length() > (i+1) // there is indeed another character to check.
&& nextLine.charAt(i+1) == quotechar ){ // ..and that char. is a quote also.
// we have two quote chars in a row == one quote char, so consume them both and
// put one on the token. we do *not* exit the quoted text.
sb.append(nextLine.charAt(i+1));
i++;
}else{
inQuotes = !inQuotes;
// the tricky case of an embedded quote in the middle: a,bc"d"ef,g
if(i>2 //not on the begining of the line
&& nextLine.charAt(i-1) != this.separator //not at the begining of an escape sequence
&& nextLine.length()>(i+1) &&
nextLine.charAt(i+1) != this.separator //not at the end of an escape sequence
){
sb.append(c);
}
}
} else if (c == separator && !inQuotes) {
tokensOnThisLine.add(sb.toString());
sb = new StringBuffer(); // start work on next token
} else {
sb.append(c);
}
}
} while (inQuotes);
tokensOnThisLine.add(sb.toString());
return (String[]) tokensOnThisLine.toArray(new String[0]);
}
public void close() throws IOException{
br.close();
}
}

Have you tried to check first
if (RowData[1]!=null) or possibly if (RowData[1]!="")
I don't see why that would cause your app to crash though,
it should just set value to null or ""

I'm not understanding the following code

I have to understand this code to create my own app(almost based on this function):
public static String[][] ReadFilePerLine(Context context, String nom) {
int i = 0;
try {
FileInputStream fIn = context.openFileInput(nom);
InputStreamReader ipsr = new InputStreamReader(fIn);
BufferedReader b = new BufferedReader(ipsr);
i = getLineNumber(context, nom);
String[][] s = new String[2][i/2];
i = 0;
String ligne;
int j = 0;
while ((ligne = b.readLine()) != null) {
if (i % 2 == 0)
s[0][j] = ligne;
else {
s[1][j] = ligne;
j++;
}
i++;
}
fIn.close();
ipsr.close();
return s;
}
catch (Exception e)
{}
I'm not understanding why the using of a 2D array? and with two rows ?(String[][] s = new String[2][i/2];)
here is the data that it will be stored in the file:
data = date + " : " + y + "L/100KM"+ " " + value1 + "L "+ value2 + "KM\n";
Necessary functions:
public void updatelv(Activity activity) {
SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(context);
String fileName = getResources().getString(R.string.fileName);
fileDir = "" + preferences.getString("login", "") + "."+ preferences.getString("marque", "") + ".";
s = myIO.ReadFilePerLine(getApplicationContext(), fileDir+fileName);
ListView L = (ListView) findViewById(R.id.lv);
L.setAdapter(new ArrayAdapter<String>(this, R.layout.list_item, s[0]));
for (int i = 0; i< s[0].length; i++) {
Log.d("Saves",s[0][i]);
}
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.histo);
context = getApplicationContext();
activity = this;
final SharedPreferences preferences = PreferenceManager
.getDefaultSharedPreferences(context);
String fileName = getResources().getString(R.string.fileName);
fileDir = "" + preferences.getString("login", "") + "."+ preferences.getString("marque", "") + ".";
s = myIO.ReadFilePerLine(getApplicationContext(), fileDir + fileName);
updatelv(this);
ListView L = (ListView) findViewById(R.id.lv);
L.setTextFilterEnabled(true);
L.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// When clicked, show a toast with the TextView text
String tmp = s[1][position];
if (tmp == null)
tmp = "Aucun fichier trouvé!";
Toast.makeText(getApplicationContext(), tmp, Toast.LENGTH_SHORT)
.show();
}
});
ReadFilePerLine function:
public static String[][] ReadFilePerLine(Context context, String nom) {
int i = 0;
try {
FileInputStream fIn = context.openFileInput(nom);
InputStreamReader ipsr = new InputStreamReader(fIn);
BufferedReader b = new BufferedReader(ipsr);
i = getLineNumber(context, nom);
String[][] s = new String[2][i/2];
i = 0;
String ligne;
int j = 0;
while ((ligne = b.readLine()) != null) {
if (i % 2 == 0)
s[0][j] = ligne;
else {
s[1][j] = ligne;
j++;
}
i++;
}
fIn.close();
ipsr.close();
return s;
}
catch (Exception e)
{
}
Thank you for you help.

The code is clearly reading from a file whose format consists of pairs of lines; it puts the first line of each pair in s[0][...] and the second line of each pair in s[1][...]. If your format doesn't have that peculiarity -- which it doesn't sound as if it does -- then you don't need to do that. Just make an ordinary 1-dimensional array of Strings.

It appears that what they are doing is breaking the file down into two lists (or String arrays, in this case), one which contains all the even-numbered lines, and one which contains all the odd-numbered lines. I'll comment up the code for you:
public static String[][] ReadFilePerLine(Context context, String nom) {
int i = 0;
try {
//open the specified input file and create a reader
FileInputStream fIn = context.openFileInput(nom);
InputStreamReader ipsr = new InputStreamReader(fIn);
BufferedReader b = new BufferedReader(ipsr);
//get the total number of lines in the file, and allocate
//a buffer large enough to hold them all
i = getLineNumber(context, nom);
String[][] s = new String[2][i/2];
i = 0; //set the current line to 0
String ligne;
int j = 0; //set the section index to 0
//now read through the lines in the file, and place every
//even-numbered line in the first section ('s[0]'), and every
//odd-numbered line in the second section ('s[1]')
while ((ligne = b.readLine()) != null) {
if (i % 2 == 0)
//even-numbered line, it goes into the first section
s[0][j] = ligne;
else {
//odd-numbered line, it goes into the second section
s[1][j] = ligne;
j++; //increment the section index
}
i++; //increment the line count
}
//done, cleanup and return
fIn.close();
ipsr.close();
return s;
}
catch (Exception e) {
//should at least log an error here...
}
}
As to why they chose to use a String[][], I cannot say. Probably for convenience, since they want a single object that they can return from this function that contains both lists. Personally I would use a Map that has two List instances in it, but the String[][] works just as well and is probably marginally more efficient.
Judging from your example data it does not appear that you need to use this format. But if you want to use it, you need to structure your data so that the key is on one line, and its associated value is on the next, like:
date
2011-03-19
userName
someGuy

it seems to read from a file, split it into the two dimensional array (based on row count).
Why it does it? I have no idea why you'd want that. Check out the function that it returns s to and find out!