How to Extract float numeric data from a string - java

Hey Guys i am using Google Currency Api to request for currency conversions information.
For example i use Google Currency Api
to convert 1USD to my local Currency.
The string returned is {lhs: "1 U.S. dollar",rhs: "2 481.38958 Ugandan shillings",error: "",icc: true}
I need java code to extract the 2481.38958 float data type and save it in a float Variable.
Please Help.
Thanks alot.

For your input JSON string:
{lhs: "1 U.S. dollar",rhs: "2481.38958 Ugandan shillings",error: "",icc: true}
Using http://json-lib.sourceforge.net/ :
JSONObject json = (JSONObject) JSONSerializer.toJSON( jsonTxt );
String dollarString = json.getFloat( "rhs" );
float dollars = Float.parseFloat(dollarString.split(" ")[0]);

Considering the value always will be between rhs: and a word.
String str = "{lhs: \"1 U.S. dollar\",rhs: \"2 481.38958 Ugandan shillings\",error: \"\",icc: true}";
Matcher m = Pattern.compile("rhs:\\s.*?([\\d\\s\\.]+)\\s\\w+").matcher(str);
m.find();
float value = Float.parseFloat(m.group(1).replaceAll("[^\\d\\.]", ""));
System.out.println(value);

This string is at JSON format. There are libs for manipulate this as an object.
Examples : GSON (http://code.google.com/p/google-gson/) or http://www.json.org/java/
Something like :
new JSONObject("{lhs: "1 U.S. dollar",rhs: "2 481.38958 Ugandan shillings",error: "",icc: true}").get("rhs")
And after you have to suppress unit, maybe with a regexp.
And finally... Float.parseFloat("2 481.38958")

If the response always contains the same pattern (with Ugandan shillings text), one possible way of doing it is something like this:
package so;
import java.util.StringTokenizer;
public class DemoString {
public static void main(String[] args) {
String s = new String("{lhs: \"1 U.S. dollar\",rhs: \"2 481.38958 Ugandan shillings\",error: \"\",icc: true}") ;
StringTokenizer st = new StringTokenizer(s, "\"");
st.nextToken(); //{lhs:
st.nextToken(); //1 U.S. dollar
st.nextToken(); //,rhs:
String value = st.nextToken(); //2 481.38958 Ugandan shillings
String num = value.substring(0, value.indexOf("U")); // 2 481.38958
num = num.replaceAll(" ", "");
Float fnum = 0f;
try {
fnum = Float.parseFloat(num);
} catch (Exception e) {
e.printStackTrace(System.out);
}
System.out.println("The float number is: " + fnum.toString());
}
}

Related

Android String format not working

I have a problem with String.format In android I want replace { 0 } with my id.
My this code not working:
String str = "abc&id={0}";
String result = String.format(str, "myId");
I think you should use replace method instead of format.
String str = "abc&id={0}";
str.replace("{0}","myId");
you have 2 ways to do that and you are mixing them :)
1.String format:
String str = "abc&id=%s";//note the format string appender %s
String result = String.format(str, "myId");
or
2.Message Format:
String str = "abc&id={0}"; // note the index here, in this case 0
String result = MessageFormat.format(str, "myId");
You have to set your integer value as a seperate variable.
String str = "abc&id";
int myId = 001;
String result = str+myId;
try this,
String result = String.format("abc&id=%s", "myId");
edit if you want more than one id,
String.format("abc&id=%s.id2=%s", "myId1", "myId2");
The syntax you're looking for is:
String str = "abc&id=%1$d";
String result = String.format(str, id);
$d because it's a decimal.
Other use case:
String.format("More %2$s for %1$s", "Steven", "coffee");
// ==> "More coffee for Steven"
which allows you to repeat an argument any number of times, at any position.

Parsing String in Java, then storing in variables

I need help to parse a string in Java... I'm very new to Java and am not sure how to go about it.
Suppose the string I want to parse is...
String str = "NC43-EB2;49.21716;-122.667252;49.216757;-122.666235;"
What I would want to do is:
String name = C43
String direction = EB2;
Then what I'd like to do is store 2 coordinates as a pair...
Coordinate c1 = 49.21716;-122.667252;
Coordinate c2 = 49.216757;-122.666235;
And then make a List to store c1 and c2.
So far I have this:
parseOnePattern(String str) {
String toParse = str;
name = toParse.substring(1, toParse.indexOf("-"));
direction = toParse.substring(toParse.indexOf("-", toParse.indexOf(";")));
I'm not sure how to move forward. Any help will be appreciated.
A simple substring function may solve your problem.
String str = "NC43-EB2;49.21716;-122.667252;49.216757;-122.666235;";
String[]s = str.split(";");
String[]n = s[0].split("-");
String name = n[0].substring(1);
String direction = n[1];
String c1 = s[1] +";"+s[2];
String c2 = s[3] +";"+s[4];
System.out.println(name + " " + direction);
System.out.println(c1 + " " + c2);
I hope this helps you.
Welcome to Java and the whole set of operations it allows to perform on Strings. You have a whole set of operations to perform, I will give you the code to perform some of them and get you started :-
public void breakString() {
String str = "NC43-EB2;49.21716;-122.667252;49.216757;-122.666235";
// Will break str to "NC43-EB2" and "49.21716" "-122.667252" "49.216757" "-122.666235"
String [] allValues = str.split(";", -1);
String [] nameValuePair = allValues[0].split("-");
// substring selects only the specified portion of string
String name = nameValuePair[0].substring(1, 4);
// Since "49.21716" is of type String, we may need it to parse it to data type double if we want to do operations like numeric operations
double c1 = 0d;
try {
c1 = Double.parseDouble(allValues[1]);
} catch (NumberFormatException e) {
// TODO: Take corrective measures or simply log the error
}
What I would suggest you is to go through the documentation of String class, learn more about operations like String splitting and converting one data type to another and use an IDE like Eclipse which has very helpful features. Also I haven't tested the code above, so use it as a reference and not as a template.
Ok i made this:
public static void main(String[] args) {
String str = "NC43-EB2;49.21716;-122.667252;49.216757;-122.666235;";
String[] strSplit = str.split(";");
String[] nameSplit=strSplit[0].split("-");
String name=nameSplit[0].replace("N", "");
String direction= nameSplit[1];
String cordanateOne = strSplit[1]+";"+strSplit[2]+";";
String cordanateTwo = strSplit[3]+";"+strSplit[4]+";";
System.out.println("Name: "+name);
System.out.println("Direction: "+direction);
System.out.println("Cordenate One: "+cordanateOne);
System.out.println("Cordenate Two: "+cordanateTwo);
}
Name: C43
Direction: EB2
Cordenate One: 49.21716;-122.667252;
Cordenate Two: 49.216757;-122.666235;
String str3 = "NC43-EB2;49.21716;-122.667252;49.216757;-122.666235;";
String sub = str3.substring(0,4); // sub = NC43
String sub4 = str3.substring(5,9); // sub = EB2;
HashMap<String, String> hm = new HashMap<>();
hm.put(str3.substring(9 ,30), str3.substring(30));
hm.forEach((lat, lot) -> {
System.out.println(lat + " - " + lot); // 49.21716;-122.667252; - 49.216757;-122.666235;
});
//edit if using an array non pairs (I assumed it was lat + lon)
List<String> coordList = new ArrayList<>();
coordList.add(str3.substring(9 ,30));
coordList.add(str3.substring(30));
coordList.forEach( coord -> {
System.out.println(coord);
});
//output : 49.21716;-122.667252;
49.216757;-122.666235;

Cut ':' && " " from a String with a tokenizer

right now I am a little bit confused. I want to manipulate this string with a tokenizer:
Bob:23456:12345 Carl:09876:54321
However, I use a Tokenizer, but when I try:
String signature1 = tok.nextToken(":");
tok.nextToken(" ")
I get:
12345 Carl
However I want to have the first int and the second int into a var.
Any ideas?
You have two different patterns, maybe you should handle both separated.
Fist you should split the space separated values. Only use the string split(" "). That will return a String[].
Then for each String use tokenizer.
I believe will works.
Code:
String input = "Bob:23456:12345 Carl:09876:54321";
String[] words = input.split(" ")
for (String word : words) {
String[] token = each.split(":");
String name = token[0];
int value0 = Integer.parseInt(token[1]);
int value1 = Integer.parseInt(token[2]);
}
Following code should do:
String input = "Bob:23456:12345 Carl:09876:54321";
StringTokenizer st = new StringTokenizer(input, ": ");
while(st.hasMoreTokens())
{
String name = st.nextToken();
String val1 = st.nextToken();
String val2 = st.nextToken();
}
Seeing as you have multiple patterns, you cannot handle them with only one tokenizer.
You need to first split it based on whitespace, then split based on the colon.
Something like this should help:
String[] s = "Bob:23456:12345 Carl:09876:54321".split(" ");
System.out.println(Arrays.toString(s ));
String[] so = s[0].split(":", 2);
System.out.println(Arrays.toString(so));
And you'd get this:
[Bob:23456:12345, Carl:09876:54321]
[Bob, 23456:12345]
If you must use tokeniser then I tink you need to use it twice
String str = "Bob:23456:12345 Carl:09876:54321";
StringTokenizer spaceTokenizer = new StringTokenizer(str, " ");
while (spaceTokenizer.hasMoreTokens()) {
StringTokenizer colonTokenizer = new StringTokenizer(spaceTokenizer.nextToken(), ":");
colonTokenizer.nextToken();//to igore Bob and Carl
while (colonTokenizer.hasMoreTokens()) {
System.out.println(colonTokenizer.nextToken());
}
}
outputs
23456
12345
09876
54321
Personally though I would not use tokenizer here and use Claudio's answer which splits the strings.

Read multiple variables from a string using regex

I'm trying to split a string into different variables. Something like the opposite of String.format(). I want a particular regex to match and then that portion of the string should be assigned to a specific variable. Is that possible using StringReader or any other class?
Example my String is 5 13-DEC-2010 16:47 A Tach 220 380
now it should be assigned to variables like:
number = 5
date = 13-DEC-2010
time = 16:47
type = A Tach
num1 = 220
num2 = 380
where all variables can be strings
public static void main(String[] args) {
String s = "5 13-DEC-2010 16:47 A Tach 220 380";
String re = "(\\d+)\\s+(\\d{1,2}-[A-Z]{3}-\\d{4})\\s+(\\d{2}:\\d{2})\\s+([\\w\\s+]*)\\s+(\\d+)\\s+(\\d+)";
Pattern p = Pattern.compile(re);
String number=null,date=null,time=null,type=null,num1=null,num2=null;
Matcher m = p.matcher(s);
if (m.matches()) {
number = m.group(1);
date = m.group(2);
time = m.group(3);
type = m.group(4);
num1 = m.group(5);
num2 = m.group(6);
}
System.out.println(number);
System.out.println(date);
System.out.println(time);
System.out.println(type);
System.out.println(num1);
System.out.println(num2);
}
Try this:
var s = '5 13-DEC-2010 16:47 A Tach 220 380';
var re = /(\d+)\s+(\d{1,2}-[A-Z]{3}-\d{4})\s+(\d{2}:\d{2})\s+([\w\s+]*)\s+(\d+)\s+(\d+)/
var m = s.match(re);
Base from my past experience, there wasn't any builtin class that will do that. Just manually manipulate your data. Like split it (str.split("\s");), then stored in they respective variables. But the problem is the case "A Tach".
If you ask me I'll just replace the data seperator(in your case its a space) with a regex that will not occur in your string, something like ";=;" where your string will be transformed into
"5;=;13-DEC-2010;=;16:47;=;A Tach;=;220;=;380"
Then just split the data and parse it to their respective variable.

Tokenize a string with a space in java

I want to tokenize a string like this
String line = "a=b c='123 456' d=777 e='uij yyy'";
I cannot split based like this
String [] words = line.split(" ");
Any idea how can I split so that I get tokens like
a=b
c='123 456'
d=777
e='uij yyy';
The simplest way to do this is by hand implementing a simple finite state machine. In other words, process the string a character at a time:
When you hit a space, break off a token;
When you hit a quote keep getting characters until you hit another quote.
Depending on the formatting of your original string, you should be able to use a regular expression as a parameter to the java "split" method: Click here for an example.
The example doesn't use the regular expression that you would need for this task though.
You can also use this SO thread as a guideline (although it's in PHP) which does something very close to what you need. Manipulating that slightly might do the trick (although having quotes be part of the output or not may cause some issues). Keep in mind that regex is very similar in most languages.
Edit: going too much further into this type of task may be ahead of the capabilities of regex, so you may need to create a simple parser.
line.split(" (?=[a-z+]=)")
correctly gives:
a=b
c='123 456'
d=777
e='uij yyy'
Make sure you adapt the [a-z+] part in case your keys structure changes.
Edit: this solution can fail miserably if there is a "=" character in the value part of the pair.
StreamTokenizer can help, although it is easiest to set up to break on '=', as it will always break at the start of a quoted string:
String s = "Ta=b c='123 456' d=777 e='uij yyy'";
StreamTokenizer st = new StreamTokenizer(new StringReader(s));
st.ordinaryChars('0', '9');
st.wordChars('0', '9');
while (st.nextToken() != StreamTokenizer.TT_EOF) {
switch (st.ttype) {
case StreamTokenizer.TT_NUMBER:
System.out.println(st.nval);
break;
case StreamTokenizer.TT_WORD:
System.out.println(st.sval);
break;
case '=':
System.out.println("=");
break;
default:
System.out.println(st.sval);
}
}
outputs
Ta
=
b
c
=
123 456
d
=
777
e
=
uij yyy
If you leave out the two lines that convert numeric characters to alpha, then you get d=777.0, which might be useful to you.
Assumptions:
Your variable name ('a' in the assignment 'a=b') can be of length 1 or more
Your variable name ('a' in the assignment 'a=b') can not contain the space character, anything else is fine.
Validation of your input is not required (input assumed to be in valid a=b format)
This works fine for me.
Input:
a=b abc='123 456' &=777 #='uij yyy' ABC='slk slk' 123sdkljhSDFjflsakd#*#&=456sldSLKD)#(
Output:
a=b
abc='123 456'
&=777
#='uij yyy'
ABC='slk slk'
123sdkljhSDFjflsakd#*#&=456sldSLKD)#(
Code:
import java.util.ArrayList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class RegexTest {
// SPACE CHARACTER followed by
// sequence of non-space characters of 1 or more followed by
// first occuring EQUALS CHARACTER
final static String regex = " [^ ]+?=";
// static pattern defined outside so that you don't have to compile it
// for each method call
static final Pattern p = Pattern.compile(regex);
public static List<String> tokenize(String input, Pattern p){
input = input.trim(); // this is important for "last token case"
// see end of method
Matcher m = p.matcher(input);
ArrayList<String> tokens = new ArrayList<String>();
int beginIndex=0;
while(m.find()){
int endIndex = m.start();
tokens.add(input.substring(beginIndex, endIndex));
beginIndex = endIndex+1;
}
// LAST TOKEN CASE
//add last token
tokens.add(input.substring(beginIndex));
return tokens;
}
private static void println(List<String> tokens) {
for(String token:tokens){
System.out.println(token);
}
}
public static void main(String args[]){
String test = "a=b " +
"abc='123 456' " +
"&=777 " +
"#='uij yyy' " +
"ABC='slk slk' " +
"123sdkljhSDFjflsakd#*#&=456sldSLKD)#(";
List<String> tokens = RegexTest.tokenize(test, p);
println(tokens);
}
}
Or, with a regex for tokenizing, and a little state machine that just adds the key/val to a map:
String line = "a = b c='123 456' d=777 e = 'uij yyy'";
Map<String,String> keyval = new HashMap<String,String>();
String state = "key";
Matcher m = Pattern.compile("(=|'[^']*?'|[^\\s=]+)").matcher(line);
String key = null;
while (m.find()) {
String found = m.group();
if (state.equals("key")) {
if (found.equals("=") || found.startsWith("'"))
{ System.err.println ("ERROR"); }
else { key = found; state = "equals"; }
} else if (state.equals("equals")) {
if (! found.equals("=")) { System.err.println ("ERROR"); }
else { state = "value"; }
} else if (state.equals("value")) {
if (key == null) { System.err.println ("ERROR"); }
else {
if (found.startsWith("'"))
found = found.substring(1,found.length()-1);
keyval.put (key, found);
key = null;
state = "key";
}
}
}
if (! state.equals("key")) { System.err.println ("ERROR"); }
System.out.println ("map: " + keyval);
prints out
map: {d=777, e=uij yyy, c=123 456, a=b}
It does some basic error checking, and takes the quotes off the values.
This solution is both general and compact (it is effectively the regex version of cletus' answer):
String line = "a=b c='123 456' d=777 e='uij yyy'";
Matcher m = Pattern.compile("('[^']*?'|\\S)+").matcher(line);
while (m.find()) {
System.out.println(m.group()); // or whatever you want to do
}
In other words, find all runs of characters that are combinations of quoted strings or non-space characters; nested quotes are not supported (there is no escape character).
public static void main(String[] args) {
String token;
String value="";
HashMap<String, String> attributes = new HashMap<String, String>();
String line = "a=b c='123 456' d=777 e='uij yyy'";
StringTokenizer tokenizer = new StringTokenizer(line," ");
while(tokenizer.hasMoreTokens()){
token = tokenizer.nextToken();
value = token.contains("'") ? value + " " + token : token ;
if(!value.contains("'") || value.endsWith("'")) {
//Split the strings and get variables into hashmap
attributes.put(value.split("=")[0].trim(),value.split("=")[1]);
value ="";
}
}
System.out.println(attributes);
}
output:
{d=777, a=b, e='uij yyy', c='123 456'}
In this case continuous space will be truncated to single space in the value.
here attributed hashmap contains the values
import java.io.*;
import java.util.Scanner;
public class ScanXan {
public static void main(String[] args) throws IOException {
Scanner s = null;
try {
s = new Scanner(new BufferedReader(new FileReader("<file name>")));
while (s.hasNext()) {
System.out.println(s.next());
<write for output file>
}
} finally {
if (s != null) {
s.close();
}
}
}
}
java.util.StringTokenizer tokenizer = new java.util.StringTokenizer(line, " ");
while (tokenizer.hasMoreTokens()) {
String token = tokenizer.nextToken();
int index = token.indexOf('=');
String key = token.substring(0, index);
String value = token.substring(index + 1);
}
Have you tried splitting by '=' and creating a token out of each pair of the resulting array?

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