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Extract specific string by regular expression in Android [duplicate]

This question already has an answer here:
Select part of line in regular expression
(1 answer)
Closed 4 years ago.
I have this strings: https://regex101.com/r/7Er0Ch/6
I want put all my http://esupb.tabriz.ir:808x/srvSC.svc into array list.So in order to i used matcher like blow:
String regx= "#\\d+#";
Pattern pattern = Pattern.compile(regx);
Matcher matcher = pattern.matcher(url);
String[] metadata = new String[4];
while (matcher.find()) {
metadata[0] = matcher.group(1);
metadata[1] = matcher.group(2);
metadata[2] = matcher.group(3);
metadata[3] = matcher.group(4);
}
but I got not appropriate result. What is my mistake?

From requirement your regex will be
"(#\d+#)(http[^#]*svc)(#\d+#)"
group(0): (#\\d+#)(http[^#]*svc)(#\\d+#)
group(1): (#\\d+#)
group(2): (http[^#]*svc)
group(3): (#\\d+#)
Change your code to
List<String> urls = new ArrayList<>();
String url =
"#1#http://test.com:8080/srv.svc#1# " +
"#2#http://test.com:8081/srv.svc#2# " +
"#3#http://test.com:8082/srv.svc#3# " +
"#4#http://test.com:8083/srv.svc#4# " +
"#5#http://test.com:8084/srv.svc#5# ";
String regx = "(#\\d+#)(http[^#]*svc)(#\\d+#)";
Pattern pattern = Pattern.compile(regx);
Matcher matcher = pattern.matcher(url);
int from = 0;
while (matcher.find(from)) {
urls.add(matcher.group(2));
from = matcher.start() + 1;
}

You regex #\\d+#matches # followed by matching one or more times a digit and then another # .It does not use capturing groups.
For your example data you could remove that match from the string giving you the desired result leaving out matching any pattern for the string that is left. It could also match inside the string instead of only at the start and the end.
To match your example string(s) like http://esupb.tabriz.ir:808x/srvSC.svc you might use your regex to match the start and the end, and capture in a group what is in between.
^#\d+#(https?://test.ir:808\d/srvSC\.svc)#\d+#$
In Java
^#\\d+#(https?://test.ir:808\\d/srvSC\\.svc)#\\d+#$
Regex demo
Demo Java
Explanation
^ Assert the start of the string
#\d+# Match #, one or more times a digit and another #
( Start capturing group
https?://test.ir:808\d Match the start of the url with an optional s s? and a digit after 808. Use \d+ to match one or more digits.
/srvSC\.svc Match /srvSC.svc
#\d+# Match #, one or more times a digit and another #
) Close caputring group
$ Assert the end of the string

Converting string with time to minutes

I am working on an Android app that gets a time (duration) value as string.
For example, the app can get a value like: 6 hours 43 mins
or a value like: 15 mins
I am looking for a way to convert this strings to an integer value in minutes.
I have tried using this function, but I can´t extract the needed values:
str = str.replaceAll("[^\\d.]", "");
Edit:
it could be possible a result like 6 hours, the only known condition is that minutes are always rounded to an integer, the minimum value is 1 min

Using a Regex to get each couple numeric/time_unit. You can easily parse that with :
(\\d+) (\\w+)
Group 1 : numeric value
Group 2 : time unit
(note that I used a space between the two (could be optional if you want)
Using Java Pattern class to use that regex
Pattern p = Pattern.compile("(\\d+) (\\w+)");
Then you just have to iterate on each match to get the couple type/value
Matcher m = p.matcher(s);
while(m.find()){
String type = m.group(2);
int value = Integer.parseInt(m.group(1))
...
}
From that, just use a switch to convert the number into minute and add it to the variable, omitting the break to have a nice (but not efficient) converter :
switch(type){
//Add more time unit in the correct order if needed
case "days":
value *= 24;
case "hours":
value *= 60;
case "mins":
mins += value;
break;
}
Each type will convert the value into a correct number of minute, at the end, you will have the result in minutes.

Problem: There are few concerns as you never know without putting extra conditions like:
15 hours and 15 mins both will be stored in same integer value , you eventually need to differentiate them on some conditions to cater all the issues.
Coming to the question, you may achieve all this by using String split cases but you need to manually cater all the cases keeping in mind a user can use any spell words like hours can be hrs and so on

You could split the String at the whitespace and use the values in the array.
String value1 = "6 hours 43 mins";
String value2 = "15 mins";
String[] resultList1 = value1.split(" ");
String[] resultList2 = value2.split(" ");
int minutes1 = 0;
int minutes2 = 0;
if(resultList1.length == 4) {
minutes1 = Integer.parseInt(resultList1[0]) * 60 + Integer.parseInt(resultList1[2]);
} else {
minutes1 = Integer.parseInt(resultList1[0]);
}
if(resultList2.length == 4) {
minutes2 = Integer.parseInt(resultList2[0]) * 60 + Integer.parseInt(resultList2[2]);
} else {
minutes2 = Integer.parseInt(resultList2[0]);
}
System.out.println(minutes1);
System.out.println(minutes2);
The result is:
403
15

Either String split() or Pattern Matcher, as earlier answers suggest, will work. I'm not sure which will be more efficient though, but it's probably irrelevant in this case. My version:
String timeStr = "2 hours 15 mins";
String[] parts = timeStr.split(" ");
int totalMins = 0;
for(int i=1; i< parts.length; i+=2) {
// Add checking for "days", etc., if necessary.
if(parts[i].equals("hours")) {
int h = Integer.parseInt(parts[i-1]);
totalMins += 60 * h;
} else if(parts[i].equals("mins")) {
int m = Integer.parseInt(parts[i-1]);
totalMins += m;
}
}
System.out.println("totalMins = " + totalMins);
>> totalMins = 135

If you can get each minute and hours separately you can use string.replace("mins", "") then use Integer.parseInt().
If you get overral like 6 hours 43 mins you must split the string.

I am not sure whether this can be done in a single regex, but if I were you I would use a different regex to find the number of hours, the number of minutes, the number of seconds, etc.
Given a string in the format you mentioned, you can first extract the number of hours by using this regex:
\d+(?= hours?)
Then extract the number of minutes:
\d+(?= mins?)
If seconds can appear in the input string, you can use this to extract seconds as well:
\d+(?= secs?)
If any of the regexes don't match, that means there isn't that information in the string.

String time = "6 hours 43 mins";//or (43 mins) or (6 hours)
int h, m;
String[] parts = time.split(" ");
if (parts.length == 4) {
h = parts[1];
m = parts[3];
} else if (parts.length == 2) {
if (parts[1].isEqualTo("hours") {
h = parts[0];
} else if (parts[1].isEqualTo("mins") {
m = parts[0];
}
}
return h*60+m;

I need to separate the text from a string based on column names

I am working on OCR based Android app, getting this text as string from the attached image dynamically (getting the text in Horizontal Direction from the image)
Text from Image:
"Part Name Part Cost Engine Oil and Oil Filter Replacement Rs 10K Alf Filter Rs 4500 Cabin AC Micro Filter Rs 4000 Pollen Filter Rs 1200 - 1500 AC Disinfectant Rs 3000 Fuel Filter Rs 6000 - 8000 Spark Plug Set Replacement (Applicable in TFSI / Petrol Car Range) Rs 10K Body Wash, Basic Clean 8. Engine Degrease Rs 3000 Body Wax Polish Detailed Rs 7000 - 8000 Car interior Dry Clean with Genn Clean Rs 8000 - 10000 Wheel Alignment \u0026 Balancing Rs 6000 - 7000 Brake Pads Replacernent (Pair) Rs 30K - 32K Brake Disc Replacernent (Pair) Rs 30K - 35K ..........".
I need to separate the Part Name and Part Cost(just 2 columns i.e Part Name, Part Cost) (ignore all extra text from the column heading). Separate the values from String and should store it in SQLIte Database Android. I am stuck how to get the values and separate them.

The text returned from the OCR isn't ideal. The first thing you should do is check if whatever OCR solution can be configured to provide a better output. Ideally, you want the lines to be separated by newline characters and the space between the columns to be interpreted as something more useful, such as a tab character.
If you have no way of changing the text you get, you'll have to find some way of parsing it. You may want to look into using a parser, such as ANTLR to make this easier.
The following observations may help you to come up with a parsing strategy:
Column 2 items all start with "Rs" or "Upto Rs".
Column 2 items end with:
A number (where a number is allowed to be a string of digits [0-9.], optionally followed by a "K"
"Lakh"
Column 1 items don't begin with a number or "Lakh"
So a basic algorithm could be:
List<String> column1 = new ArrayList<String>();
List<String> column2 = new ArrayList<String>();
String[] tokens = ocrString.split(" ");
List<String> column = column1;
String item = "";
for (int i = 0; i < tokens.length; i++) {
String token = tokens[i];
String nextToken = i == tokens.length - 1 ? "" : tokens[i+1];
if (column == column1) {
if (token == "Rs" || (token == "Upto" && nextToken == "Rs")) {
column = column2;
column.add(item); item = "";
i--; continue;
}
item += " " + token;
} else {
item += " " + token;
if (/*token is number or "Lakh" and nextToken is not*/) {
column.add(item); item = "";
column = column1;
}
}
}

How to get last 4 digit of number in android?

I have an app which contain mobile number edit text in which user can edit mobile number and I have to send two request to server like:- mobile number and mssdn,mobile number(which is full lenghth ) and mssdn(which contain mobile number last 4 digit).How can I do that

Try this. Check for length greater than 4 before calling subString to avoid IndexOutOfBounds Exception.
EditText mEdtPhoneNumber = (EditText) findViewById(R.id.edtPhoneNumber);
String phoneNumber = mEdtPhoneNumber.getText().toString().trim();
String strLastFourDi = phoneNumber.length() >= 4 ? phoneNumber.substring(phoneNumber.length() - 4): "";
Also what is mssdn?? Is it msisdn??

Use the modulus (%) operator:
To get the last digit: use number % 10
To get the last 2 digits: use number % 100
and so on
For example:
42455%10000 = 2455

You could do something like this:
EditText phoneNumberEditText = (EditText) findViewById(R.id.phoneNumberEditText);
String phoneNumber = phoneNumberEditText.getText().toString();
String lastFourDigits = phoneNumber.substring(phoneNumber.length() - 4);

you should use regex because this will only give you result if the last four letters are actually numbers on the other hand the substring function simply give you last four letters no matter they are numbers or characters. e.g 4344sdsdss4 will give you dss4 which is clearly not a part of phone number
String str="4444ntrjntkr555566";
Pattern p = Pattern.compile("(\\d{4})$");
Matcher m = p.matcher(str);
if (m.find()) {
System.out.println(m.group(m.groupCount()));
}
this will produce 5566
Working
//d mean digits
{4} for fix length as 4
$ mean at the end

List<Integer> f(String str){
ArrayList<Integer> digits = new ArrayList<>();
if (null == str || str.length() < 4){
Log.i(LOG_TAG, "there are less than 4 digits");
return digits;
}
String digitsStr = str.substring(str.length() - 4);
for (char c : digitsStr.toCharArray()){
try {
Integer digit = Integer.parseInt(String.valueOf(c));
digits.add(digit);
} catch (Exception e){
continue;
}
}
return digits;
}

We can also use a new method introduced in kotlin: takeLast(n)
fun getLastDigit(data: String, n:Int): String {
return if(data.length > n){
data.takeLast(n)
}else {
""
}
}

How to get byte by byte from byte array

I am getting response from server in string format like
V1YYZZ0x0000010x0D0x00112050x0C152031962061900x0D410240x0E152031962061900x0F410240x1021TATADOCOMOINTERNET101
Then I am converting it in to byte array because i need to get value from this byte by byte.
I tried to use
Arrays.copyOfRange(original,
from , to);
but it work on index basis not on byte basis.
I also tried following solution but it also truncating String(if I use string instead of byte[]) on length basis.
public static String truncateWhenUTF8(String s, int maxBytes) {
int b = 0;
for (int i = 0; i < s.length(); i++) {
char c = s.charAt(i);
// ranges from http://en.wikipedia.org/wiki/UTF-8
int skip = 0;
int more;
if (c <= 0x007f) {
more = 1;
} else if (c <= 0x07FF) {
more = 2;
} else if (c <= 0xd7ff) {
more = 3;
} else if (c <= 0xDFFF) {
// surrogate area, consume next char as well
more = 4;
skip = 1;
} else {
more = 3;
}
if (b + more > maxBytes) {
return s.substring(0, i);
}
b += more;
i += skip;
}
return s;
}
I know how to calculate string in byte length but it giving only full string length in byte like
Here is how I need to extract packet on byte basis.
Above codes and parameters is only example. I need to get byte by byte from string/byte array.
I searched lot but didn't get any solution or link which I can refer. I am not getting how to split string using byte length because I know byte length for each parameter and for value also.
Please give me any reference or hint.

To determine what is equal to one byte in a String is not trivial. Your String contains bytes in hexadecimal text form: 0x0D (one byte, equal to 13), but also contains values as substrings. For example 1024 can be interpreted as an integer which in this case fits into 2 bytes, but could also be interpreted as a text made up by 4 chars, totaling to 8 bytes.
Anyways, I would split the string using a regular expression, and then further split the parts to length and value:
String message = "V1YYZZ0x0000010x0D0x00112050x0C152031962061900x0D41024"+
"0x0E152031962061900x0F410240x1021TATADOCOMOINTERNET101";
String regex = "(0)(x)(\\w\\w)";
String[] parts = message.split(regex);
Log.d(TAG,"HEADER = "+parts[0]);
for (int i=1; i<parts.length; i++) {
String s = parts[i];
// Only process if it has length > 0
if (s.length()>0) {
String len = "", val = "";
// String s is now in format LVVVV where L is the length, V is the value
if (s.length() < 11) {
// 1 character indicates length, up to 9 contains value
len = s.substring(0, 1);
val = s.substring(1);
} else if (s.length() > 10) {
// 2 characters indicate length, up to 99 contains value
len = s.substring(0, 2);
val = s.substring(2);
} else if (s.length() > 101) {
// 3 characters indicate length, up to 999 contains value
len = s.substring(0, 3);
val = s.substring(3);
}
Log.d(TAG, "Length: " + len + " Value: " + val);
}
}
This produces the following output:
D/Activity: HEADER = V1YYZZ
D/Activity: Length: 0 Value: 001
D/Activity: Length: 1 Value: 1205
D/Activity: Length: 15 Value: 203196206190
D/Activity: Length: 4 Value: 1024
D/Activity: Length: 15 Value: 203196206190
D/Activity: Length: 4 Value: 1024
D/Activity: Length: 21 Value: TATADOCOMOINTERNET101
Then you can check the packages (the first two package in the header is not needed), convert Strings to whatever you would like (e.g. Integer.parseInt(val))
If you explain the structure of the header (V1YYZZ0x0000010x0D0x0011205), I can improve my answer to find the message count.

I think it is doable with Scanner
import java.util.Scanner;
public class Library {
public static void main(String[] args) {
String s = "V1YYZZ0x0000010x0D0x001120"
+ "50x0C152031962061900x0D410240x0E152031962061900x0F410240x1"
+ "021TATADOCOMOINTERNET101";
// Skip first 9? bytes. I'm not sure how you define them
// so I just assumed it is 26 chars long.
s = s.substring(26, s.length());
System.out.println(s);
Scanner scanner = new Scanner(s);
// Use byte as delimiter i.e. 0xDC, 0x00
// Maybe you should use smth like 0x[\\da-fA-F]{2}
// And if you want to know that byte, you should use
// just 0x and get first 2 chars later
scanner.useDelimiter("0x\\w{2}");
// Easily extracted
int numberOfParams = scanner.nextInt();
for (int i = 0; i < numberOfParams; i++) {
String extracted = scanner.next();
// Length of message
int l = extracted.length();
boolean c = getLength(l) == getLength(l - getLength(l));
l -= getLength(l);
l = c ? l : l-1;
System.out.println("length="
+ extracted.substring(0, extracted.length()-l));
System.out.println("message="
+ extracted.substring(extracted.length()-l, extracted.length()));
}
// close the scanner
scanner.close();
}
// Counting digits assuming number is decimal
private static int getLength(int l) {
int length = (int) (Math.log10(l) + 1);
System.out.println("counted length = " + length);
return length;
}
}
We definitely need more information about rules, how string is formed. And what exactly you need to do. This code might be good enough you. And without comments it is really short and simple.

This is not a answer to accessing a byte array byte by byte, but is an answer for the situation in which you find yourself.
Your explanation and description have the appearance of being confused as to what it is that you are really getting from the server (e.g. it is quite hard to represent "V1YYZZ0x0000010x0D0x001120" as a 9 byte field (note it probably ends on the 2, not the 0)). Alternately, that you are using the wrong method to get it from the server, or not getting it as the intended data type.
Your code indicates that you believe that what you are getting is a UTF8 string. The data shown in your question does not appear to indicate that it is intended to be in that format.
Keep in mind when doing something like this that some other programmer had to create structure for the data that you are seeing. They had to define it somewhere with the intent that it be able to be decoded by their intended recipients. Unless there are other considerations (security, minimal bandwidth, etc.), such formats are usually defined in a way that is both easy to encode and decode.
The existence of the multiple "0x"-ASCII-encoded hexadecimal numbers --particularly the single byte representing the parameter (called "varam" in your graphic)-- strongly implies that this data was intended to be interpreted as a ASCII encoded string. While that might not be the case, it should be kept in mind when looking at the problem from a larger perspective.
You are having to put too much effort into decoding the information you are getting from the server. It, probably, should be relatively easy unless there are considerations why it would have intentionally been made difficult.
All of this indicates that the real problem exists in an area for which you have provided us with no information.
Step back:
Think about things like:
How are you receiving this from the server (what function/interface)?
In the call requesting the information from the server is there a way to specify the encoding type be bytes, an ASCII string, or some other format that is easier to deal with than UTF8? At a minimum, it appears to be clear that the data was not intended to be handled as a UTF8 string. There should be a way for you to get it without it having been converted to UTF8.
Also, you should try to find an actual specification for the format of the data. You have not explained much about the source, so it may be you are reverse-engineering something and have no access to specifications.
Basically, it looks like this is a problem where it might be a good idea to step back and ask if you are starting from the point that makes it easiest to solve and if you are headed in the right direction for doing so.

I'm sure I'm missing something obvious...
String.getBytes();
And if you want to process it in order taking defined objects from the array, just wrap using
ByteBuffer.wrap();
The result being something along the lines of:
String s = "OUTPUT FROM SERVER";
byte[] bytes = s.getBytes();
ByteBuffer bb = ByteBuffer.wrap(bytes);
What did I miss from the initial question? :/