Develop Reference

ReplaceAll not working

I'm using google volley to retrieve source code from website. Some looping was done to capture the value in the code. I've successfully captured the data I wanted, but error was shown: NumberFormatException: Invalid float: "2,459.00"
My intention was to store the value after the class=ListPrice>
Sample:
RM 2,899.00
The example value of the source code I wanted to save is "RM2,459.00 "
Below is the code I've written:
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_lazada_result);
lelongResult = (TextView) findViewById(R.id.lelong_result);
RequestQueue lelong = MyVolley.getRequestQueue(this);
StringRequest myLel = new StringRequest(
Method.GET,
"http://list.lelong.com.my/Auc/List/List.asp?DA=A&TheKeyword=iphone&x=0&y=0&CategoryID=&PriceLBound=&PriceUBound=",
RetrieveLelong(), createMyReqErrorListener());
lelong.add(myLel);
}
private Response.Listener<String> RetrieveLelong() {
return new Response.Listener<String>() {
#Override
public void onResponse(String response) {
ArrayList<Float> integers = new ArrayList<>();
String to = "class=ListPrice>";
String remainingText = response;
String showP = "";
while (remainingText.indexOf(to) >= 0) {
String tokenString = remainingText.substring(remainingText
.indexOf(to) + to.length());
String priceString = tokenString.substring(0,
tokenString.indexOf("<"));
float price = Float.parseFloat(priceString.replaceAll("[^\\d,]+", "").trim());
integers.add((price / 100));
remainingText = tokenString;
}
for (int i = 0; i < integers.size(); i++) {
String test1 = Float.toString(integers.get(i));
showP += test1 + "\n";
}
lelongResult.setText(showP);
}
};
}
The problem was as below:
I've tried all sort of replaceAll(),
1)replaceAll("[^\d,]+","") result:2,89900
replace all character except digits and comma works.
2)replaceAll("[^\d]+","") result:Invalid int""
replace all character include comma and dot ,not working
3)replaceAll("[^\d.]+,"") result:Invalid int""
replace all character exclude digits and dot, not working
From the experiment 2&3 coding above,I've noticed that if the comma were removed,i cant parseFloat as the value received by it is: "".NumberFormatException:Invalid Float:"" shown.
From the experiment 1,NumberFormatException:Invalid Float "2,45900" is showned.
The problem was replacing comma ,the code will not work but with the presence of comma ,the value cannot be stored into string

try this:
float price = Float.parseFloat(priceString.replaceAll("RM", "").trim());

use `replaceAll(Pattern.quote(","), "");
EDIT
if you want only numbers then use this
String s1= s.replaceAll("\D+","");

Try to parse the number by specifying the Locale.
NumberFormat format = NumberFormat.getInstance(Locale.KOREAN);
Number number = format.parse(priceString.replaceAll("RM", ""));
double d = number.doubleValue();
I'm just guessing the locale, don't know what you should use, depends on country

You need to do it one by one
priceString=priceString.replaceAll("\\D", "");
priceString=priceString.replaceAll("\\s", "");
now
priceString=priceString.trim();
float price = Float.parseFloat(priceString);

the problem is that in your code:
priceString.replaceAll(Pattern.quote(","), "");
float price = Float.parseFloat(priceString.replaceAll("\\D+\\s+", "").trim());
You are replacing coma but not storing the value!
you have to do:
priceString = priceString.replaceAll(",", "");
float price = Float.parseFloat(priceString.replaceAll("\\D+\\s+", "").trim());
I'm not sure of the pattern "\D+\s" because if you remove the coma you don't need to replace anything else (except "RM" that i assume you already removed)
Update: set locale and parse a number:
NumberFormat format = NumberFormat.getInstance(Locale.KOREAN);
Number number = format.parse(priceString.replaceAll("RM", ""));
double d = number.doubleValue();

Android get data using regexp

I have a html string in in which i am trying to get string between the tag using regexp and finally saving the value to array-list . But i am not able to get the string between the tag so my array-list is always empty.
<span><div style=\'float:left; width:350px;\'>Pharmacie DAR D\'BAGH</div>
my code to get the data using regexp is
private void findTextByRegExp()
{
ArrayList<ArrayList<String>>dataList1 = new ArrayList<ArrayList<String>>();
String pattern3 = "<span><div style=\'float:left; width:350px;\'>";
String pattern4 = "</div>";
String text = readFromFile();
Pattern p = Pattern.compile(Pattern.quote(pattern3) + "(.*?)" +
Pattern.quote(pattern4));
Matcher m = p.matcher(text);
while (m.find()) {
ArrayList<String>dataAdd = new ArrayList<String>();
dataAdd.add(m.group(1));
dataList1.add(dataAdd);
Log.d("Group data", "" + m.group(1));
}
Log.d("MY ARRAY LIST OD DATA", "" + dataList1);
}
please help me how to achieve this using regexp?

try
String pattern3 = "<span><div style=\\'float:left; width:350px;\\'>";

Send and receive string values via bluetooth android

I'm developing an app where I need to send 3 seekbar's values to a PCB via bluetooth. I've done all the bluetooth code based on the bluetoothchat example. I first modified it to send a string with these 3 values. But now, I need to do something more dificult and i don't know how to do it.
First of all, in the app i modify the seekbars and then i click on the send button. In the code, I need to set a string for each seekbar's value, because I need to access to the MCU variables and set each variable address, value, CRC etc...
So, I need to know the correct way to do this. Here is the code where i define the send function:
/**
* SEND THREAD
*/
/**[Start Thread + Send command + Nº bytes thread + Nº bytes variable + Address + Variable value + CRC]*/
public void sendValues() {
/**Set the seekbars values into a string*/
send_value1 = Integer.toString(savedProgress1);
send_value2 = Integer.toString(savedProgress2);
send_value3 = Integer.toString(savedProgress3);
String message1 = start_thread+" "+send_command+" "+num_byte_trama1+ " "+num_byte_variable+" "+pos_reg_1+" "+Value+" "+CRC;
String message2 = start_thread+" "+send_command+" "+num_byte_trama1+ " "+num_byte_variable+" "+pos_reg_2+" "+Value+" "+CRC;
String message3 = start_thread+" "+send_command+" "+num_byte_trama1+ " "+num_byte_variable+" "+pos_reg_3+" "+Value+" "+CRC;
String message4 = start_thread+" "+send_command+" "+num_byte_trama2+ " "+num_byte_variable+" "+pos_reg_save_request+" "+Value+" "+CRC;
String message5 = start_thread+" "+send_command+" "+num_byte_trama2+ " "+num_byte_variable+" "+pos_reg_save_status+" "+Value+" "+CRC;
/**Check that we're actually connected before trying anything*/
if (GlobalVar.mTransmission.getState() != GlobalVar.STATE_CONNECTED) {
Toast.makeText(this, R.string.not_connected, Toast.LENGTH_SHORT).show();
return;
}
/**Get the message bytes and tell the Transmission to write*/
byte[] send = message.getBytes();
GlobalVar.mTransmission.write(send);
/**Reset out string buffer to zero*/
GlobalVar.mOutStringBuffer.setLength(0);
}
There are these few things that I ask you to help me:
1- Need to know how to calculate the CRC
2- I need to send these 5 strings together when pressing the send button.
In the part where i get the bytes to send, I don't know If the right way to do this would be to add these 5 strings on 1 and send this one (maybe it would be to long if I do this), or to create a function to send these 5 separately but at the same time.
This is the edited code to send each message one by one:
/**Conversion to decimal of the seekbar's % value*/
send_int1 = ((savedProgress1 * 20480) / 100) * -1;
send_int2 = ((savedProgress2 * 20480) / 100) * -1;
send_int3 = ((savedProgress3 * 20480) / 100) * -1;
/**Conversion to string of the previous values to send in the string message*/
sendValue1 = Integer.toString(send_int1);
sendValue2 = Integer.toString(send_int1);
sendValue3 = Integer.toString(send_int1);
String message1 = start_thread+" "+send_command+" "+num_byte_trama1+" "+num_byte_variable+" "+pos_reg_1+" "+sendValue1+" " ;
String message2 = start_thread+" "+send_command+" "+num_byte_trama1+" "+num_byte_variable+" "+pos_reg_2+" "+sendValue2+" " ;
String message3 = start_thread+" "+send_command+" "+num_byte_trama1+" "+num_byte_variable+" "+pos_reg_3+" "+sendValue3+" " ;
String message4 = start_thread+" "+send_command+" "+num_byte_trama2+" "+num_byte_variable+" "+pos_reg_save_request+" " ;
String message5 = start_thread+" "+send_command+" "+num_byte_trama2+" "+num_byte_variable+" "+pos_reg_save_status+" " ;
/**Check that we're actually connected before trying anything*/
if (GlobalVar.mTransmission.getState() != GlobalVar.STATE_CONNECTED) {
Toast.makeText(this, R.string.not_connected, Toast.LENGTH_SHORT).show();
return;
}
/**Get the message bytes and tell the Transmission to write*/
byte[] send1 = message1.getBytes();
GlobalVar.mTransmission.write(send1);
//Wait untill I receive the confirmation from the MCU
byte[] send2 = message2.getBytes();
GlobalVar.mTransmission.write(send2);
byte[] send3 = message3.getBytes();
GlobalVar.mTransmission.write(send3);
byte[] send4 = message4.getBytes();
GlobalVar.mTransmission.write(send4);
byte[] send5 = message5.getBytes();
GlobalVar.mTransmission.write(send5);
/**Reset out string buffer to zero*/
GlobalVar.mOutStringBuffer.setLength(0);
}

For your frame, I recommand you to use this kind of frame :
final byte[] HEADER = AA11 // For example
// When you want to send a message :
Strign messageToSend = new String(HEADER) + yourStringMessage
It'll be easier for you to analyze the frame when you receive it.
Then, for the CRC, I can't answer if you don't tell the kind of CRC. In my app, I used
private static char createCRC(byte[] frame)
{
int crc = 0;
for(byte i : frame)
{
crc = crc^i;
}
return (char)crc;
}
to create the CRC by "XORing" each byte of my message , and then check a CRC is quite easy
UPDATE : Well, I finally get it.
In the BluetoothChat activity, you get a string version of message, and the byte[] one.
If you want to get the first byte of the message, just add byte myByte = readBuf[0] before String readMessage = new String(readBuf, 0, msg.arg1);
Then, String readMessage = new String(myByte, 0, msg.arg1);

How to split this String?

I want to split this string
String info = "0.542008835 meters height from ground";
from this i want to get only two decimals like this 0.54.
by using this i am getting that
String[] _new = rhs.split("(?<=\\G....)");
But i am facing problem here, if string does't contain any decimals like this string
String info = "1 meters height from ground";
for this string i am getting those characters upto first 4 in the split string like 1 me.
i want only numbers to split if it has decimals, How to solve this problem.

if(info.contains("."))
{
String[] _new = rhs.split("(?<=\\G....)");
}

I think you can check by white space after first value. see this
If you get the space then get first character only.
For checking if a string contains whitespace use a Matcher and call it's find method.
Pattern pattern = Pattern.compile("\\s");
Matcher matcher = pattern.matcher(s);
boolean found = matcher.find();
If you want to check if it only consists of whitespace then you can use String.matches:
boolean isWhitespace = s.matches("^\\s*$");

You could use a regex to do this as an alternative to Deepzz's method, this will handle the case where there is a '.' in the later part of the String, I've included an example below. It's not clear from your question is you actually want to remaining part of the String, but you could add a second group to the reg ex to capture this.
public static void main(String[] args) {
final String test1 = "1.23 foo";
final String test2 = "1 foo";
final String test3 = "1.234 foo";
final String test4 = "1.234 fo.o";
final String test5 = "1 fo.o";
getStartingDecimal(test1);
getStartingDecimal(test2);
getStartingDecimal(test3);
getStartingDecimal(test4);
getStartingDecimal(test5);
}
private static void getStartingDecimal(final String s) {
System.out.print(s + " : ");
Pattern pattern = Pattern.compile("^(\\d+\\.\\d\\d)");
Matcher matcher = pattern.matcher(s);
if(matcher.find()) {
System.out.println(matcher.group(1));
} else {
System.out.println("Doesn't start with decimal");
}
}

Assuming the number is always the first part of the string:
String numStr = rhs.split(" ")[0];
Double num = Double.parseDouble(numStr);
After that you can use the String Formatter to get the desired representation of the number.

This will work when you know the String near the numbers, with int and double numbers as well.
String a ="0.542008835 meters height from ground";
String b = a.replace(" meters height from ground", "");
int c = (int) ((Double.parseDouble(b))*100);
double d = ((double)c/100);

Extract substring from a string

what is the best way to extract a substring from a string in android?

If you know the Start and End index, you can use
String substr=mysourcestring.substring(startIndex,endIndex);
If you want to get substring from specific index till end you can use :
String substr=mysourcestring.substring(startIndex);
If you want to get substring from specific character till end you can use :
String substr=mysourcestring.substring(mysourcestring.indexOf("characterValue"));
If you want to get substring from after a specific character, add that number to .indexOf(char):
String substr=mysourcestring.substring(mysourcestring.indexOf("characterValue") + 1);

substring():
str.substring(startIndex, endIndex);

Here is a real world example:
String hallostring = "hallo";
String asubstring = hallostring.substring(0, 1);
In the example asubstring would return: h

There is another way , if you want to get sub string before and after a character
String s ="123dance456";
String[] split = s.split("dance");
String firstSubString = split[0];
String secondSubString = split[1];
check this post-
how to find before and after sub-string in a string

substring(int startIndex, int endIndex)
If you don't specify endIndex, the method will return all the
characters from startIndex.
startIndex : starting index is inclusive
endIndex : ending index is exclusive
Example:
String str = "abcdefgh"
str.substring(0, 4) => abcd
str.substring(4, 6) => ef
str.substring(6) => gh

you can use this code
public static String getSubString(String mainString, String lastString, String startString) {
String endString = "";
int endIndex = mainString.indexOf(lastString);
int startIndex = mainString.indexOf(startString);
Log.d("message", "" + mainString.substring(startIndex, endIndex));
endString = mainString.substring(startIndex, endIndex);
return endString;
}
in this mainString is a Super string.like
"I_AmANDROID.Devloper"
and lastString is a string like"." and startString is like"_".
so this function returns "AmANDROID".
enjoy your code time.:)

use text untold class from android: TextUtils.substring (charsequence source, int start, int end)

You can use subSequence , it's same as substr in C
Str.subSequence(int Start , int End)

When finding multiple occurrences of a substring matching a pattern
String input_string = "foo/adsfasdf/adf/bar/erqwer/";
String regex = "(foo/|bar/)"; // Matches 'foo/' and 'bar/'
Pattern pattern = Pattern.compile(regex);
Matcher matcher = pattern.matcher(input_string);
while(matcher.find()) {
String str_matched = input_string.substring(matcher.start(), matcher.end());
// Do something with a match found
}

The best way to get substring in Android is using (as #user2503849 said) TextUtlis.substring(CharSequence, int, int) method. I can explain why. If you will take a look at the String.substring(int, int) method from android.jar (newest API 22), you will see:
public String substring(int start) {
if (start == 0) {
return this;
}
if (start >= 0 && start <= count) {
return new String(offset + start, count - start, value);
}
throw indexAndLength(start);
}
Ok, than... How do you think the private constructor String(int, int, char[]) looks like?
String(int offset, int charCount, char[] chars) {
this.value = chars;
this.offset = offset;
this.count = charCount;
}
As we can see it keeps reference to the "old" value char[] array. So, the GC can not free it.
In the newest Java it was fixed:
String(int offset, int charCount, char[] chars) {
this.value = Arrays.copyOfRange(chars, offset, offset + charCount);
this.offset = offset;
this.count = charCount;
}
Arrays.copyOfRange(...) uses native array copying inside.
That's it :)
Best regards!

All of The responders gave good answers. However, I am giving you all relatable methods for this so that any one can get from one place, I'll edit my answer if I find something new.
substring(0)- use for cut string from given specific char.
Substring(0,2)- give you sub string from starting(0) and ending(2) characters.
Split("NAME")- return you string in two parts first is that you use in split "NAME" and another part is rest of string combine.
subSequence(0,3) - returns sequence of give start(0) and ending index(3).
This one is not specifically use for split string but though it may be use full for some one
startswith("A",3)- returns string for specific starting character.
For example:
String s = "StackOverflow";
String[] split = s.split("Stack");
System.out.println("STRING NAME:"+s.substring(2));
System.out.println("STRING NAME:"+s.substring(2,3));
System.out.println("STRING NAME:"+split[1]);
System.out.println("STRING NAME:"+split[0]);
System.out.println("STRING NAME:"+s.subSequence(2,5));
Output:
1)ackOverflow
2)a
3)Overflow
4)stack
5)ack
I hope this will give you enough information that you require.