Tokenizer java (string) - java

For example, Ive got Some stringa.b.c.d`, I have separated it by tokens. but now I want to do a specific thing with a, then something else with b, and something else with c. How can I do that?
String value="a.b.c.d";
StringTokenizer tokenize = new StringTokenizer(value, ".");
while(tokenize.hasMoreTokens()){
String separated1= tokenize.?????;
String separated2= tokenize.?????;
String Val1 = someMethod1(separated1);
String Val2 = someMethod2(separated2);
}
//tokenize next line is not solution

Just to spell out what #RealSkeptic already said, avoid the loop:
String value = "a.b.c.d";
String[] separated = value.split("\\.");
if (separated.length >= 2) {
String val1 = someMethod1(separated[0]);
String val2 = someMethod2(separated[1]);
} else {
// other processing here
}
You could do something similar with a StringTokenizer if you liked, only you would need at least two if statements to check whether there were enough tokens. But as #user3437460 said, StringTokenizer is now legacy; String.split() is recommended in new code.

Using String.split you can split about the . into an array.
How about something like this which will print each token:
String value = "a.b.c.d";
String[] tokens = value.split("\\.");
for (String token : tokens) {
System.out.println(token);
}
The . needs to be escaped as the split function takes a regexp and . is a wildcard

Why don't use split ? Easier to use and makes more sense here

Related

How to split a string in JAVA with two different seperators? [duplicate]

I want to split the string "004-034556" into two strings by the delimiter "-":
part1 = "004";
part2 = "034556";
That means the first string will contain the characters before '-', and the second string will contain the characters after '-'.
I also want to check if the string has '-' in it.
Use the appropriately named method String#split().
String string = "004-034556";
String[] parts = string.split("-");
String part1 = parts[0]; // 004
String part2 = parts[1]; // 034556
Note that split's argument is assumed to be a regular expression, so remember to escape special characters if necessary.
there are 12 characters with special meanings: the backslash \, the caret ^, the dollar sign $, the period or dot ., the vertical bar or pipe symbol |, the question mark ?, the asterisk or star *, the plus sign +, the opening parenthesis (, the closing parenthesis ), and the opening square bracket [, the opening curly brace {, These special characters are often called "metacharacters".
For instance, to split on a period/dot . (which means "any character" in regex), use either backslash \ to escape the individual special character like so split("\\."), or use character class [] to represent literal character(s) like so split("[.]"), or use Pattern#quote() to escape the entire string like so split(Pattern.quote(".")).
String[] parts = string.split(Pattern.quote(".")); // Split on the exact string.
To test beforehand if the string contains certain character(s), just use String#contains().
if (string.contains("-")) {
// Split it.
} else {
throw new IllegalArgumentException("String " + string + " does not contain -");
}
Note, this does not take a regular expression. For that, use String#matches() instead.
If you'd like to retain the split character in the resulting parts, then make use of positive lookaround. In case you want to have the split character to end up in left hand side, use positive lookbehind by prefixing ?<= group on the pattern.
String string = "004-034556";
String[] parts = string.split("(?<=-)");
String part1 = parts[0]; // 004-
String part2 = parts[1]; // 034556
In case you want to have the split character to end up in right hand side, use positive lookahead by prefixing ?= group on the pattern.
String string = "004-034556";
String[] parts = string.split("(?=-)");
String part1 = parts[0]; // 004
String part2 = parts[1]; // -034556
If you'd like to limit the number of resulting parts, then you can supply the desired number as 2nd argument of split() method.
String string = "004-034556-42";
String[] parts = string.split("-", 2);
String part1 = parts[0]; // 004
String part2 = parts[1]; // 034556-42
An alternative to processing the string directly would be to use a regular expression with capturing groups. This has the advantage that it makes it straightforward to imply more sophisticated constraints on the input. For example, the following splits the string into two parts, and ensures that both consist only of digits:
import java.util.regex.Pattern;
import java.util.regex.Matcher;
class SplitExample
{
private static Pattern twopart = Pattern.compile("(\\d+)-(\\d+)");
public static void checkString(String s)
{
Matcher m = twopart.matcher(s);
if (m.matches()) {
System.out.println(s + " matches; first part is " + m.group(1) +
", second part is " + m.group(2) + ".");
} else {
System.out.println(s + " does not match.");
}
}
public static void main(String[] args) {
checkString("123-4567");
checkString("foo-bar");
checkString("123-");
checkString("-4567");
checkString("123-4567-890");
}
}
As the pattern is fixed in this instance, it can be compiled in advance and stored as a static member (initialised at class load time in the example). The regular expression is:
(\d+)-(\d+)
The parentheses denote the capturing groups; the string that matched that part of the regexp can be accessed by the Match.group() method, as shown. The \d matches and single decimal digit, and the + means "match one or more of the previous expression). The - has no special meaning, so just matches that character in the input. Note that you need to double-escape the backslashes when writing this as a Java string. Some other examples:
([A-Z]+)-([A-Z]+) // Each part consists of only capital letters
([^-]+)-([^-]+) // Each part consists of characters other than -
([A-Z]{2})-(\d+) // The first part is exactly two capital letters,
// the second consists of digits
Use:
String[] result = yourString.split("-");
if (result.length != 2)
throw new IllegalArgumentException("String not in correct format");
This will split your string into two parts. The first element in the array will be the part containing the stuff before the -, and the second element in the array will contain the part of your string after the -.
If the array length is not 2, then the string was not in the format: string-string.
Check out the split() method in the String class.
This:
String[] out = string.split("-");
should do the thing you want. The string class has many method to operate with a string.
// This leaves the regexes issue out of question
// But we must remember that each character in the Delimiter String is treated
// like a single delimiter
public static String[] SplitUsingTokenizer(String subject, String delimiters) {
StringTokenizer strTkn = new StringTokenizer(subject, delimiters);
ArrayList<String> arrLis = new ArrayList<String>(subject.length());
while(strTkn.hasMoreTokens())
arrLis.add(strTkn.nextToken());
return arrLis.toArray(new String[0]);
}
With Java 8:
List<String> stringList = Pattern.compile("-")
.splitAsStream("004-034556")
.collect(Collectors.toList());
stringList.forEach(s -> System.out.println(s));
Use org.apache.commons.lang.StringUtils' split method which can split strings based on the character or string you want to split.
Method signature:
public static String[] split(String str, char separatorChar);
In your case, you want to split a string when there is a "-".
You can simply do as follows:
String str = "004-034556";
String split[] = StringUtils.split(str,"-");
Output:
004
034556
Assume that if - does not exists in your string, it returns the given string, and you will not get any exception.
The requirements left room for interpretation. I recommend writing a method,
public final static String[] mySplit(final String s)
which encapsulate this function. Of course you can use String.split(..) as mentioned in the other answers for the implementation.
You should write some unit-tests for input strings and the desired results and behaviour.
Good test candidates should include:
- "0022-3333"
- "-"
- "5555-"
- "-333"
- "3344-"
- "--"
- ""
- "553535"
- "333-333-33"
- "222--222"
- "222--"
- "--4555"
With defining the according test results, you can specify the behaviour.
For example, if "-333" should return in [,333] or if it is an error.
Can "333-333-33" be separated in [333,333-33] or [333-333,33] or is it an error? And so on.
To summarize: there are at least five ways to split a string in Java:
String.split():
String[] parts ="10,20".split(",");
Pattern.compile(regexp).splitAsStream(input):
List<String> strings = Pattern.compile("\\|")
.splitAsStream("010|020202")
.collect(Collectors.toList());
StringTokenizer (legacy class):
StringTokenizer strings = new StringTokenizer("Welcome to EXPLAINJAVA.COM!", ".");
while(strings.hasMoreTokens()){
String substring = strings.nextToken();
System.out.println(substring);
}
Google Guava Splitter:
Iterable<String> result = Splitter.on(",").split("1,2,3,4");
Apache Commons StringUtils:
String[] strings = StringUtils.split("1,2,3,4", ",");
So you can choose the best option for you depending on what you need, e.g. return type (array, list, or iterable).
Here is a big overview of these methods and the most common examples (how to split by dot, slash, question mark, etc.)
You can try like this also
String concatenated_String="hi^Hello";
String split_string_array[]=concatenated_String.split("\\^");
Assuming, that
you don't really need regular expressions for your split
you happen to already use apache commons lang in your app
The easiest way is to use StringUtils#split(java.lang.String, char). That's more convenient than the one provided by Java out of the box if you don't need regular expressions. Like its manual says, it works like this:
A null input String returns null.
StringUtils.split(null, *) = null
StringUtils.split("", *) = []
StringUtils.split("a.b.c", '.') = ["a", "b", "c"]
StringUtils.split("a..b.c", '.') = ["a", "b", "c"]
StringUtils.split("a:b:c", '.') = ["a:b:c"]
StringUtils.split("a b c", ' ') = ["a", "b", "c"]
I would recommend using commong-lang, since usually it contains a lot of stuff that's usable. However, if you don't need it for anything else than doing a split, then implementing yourself or escaping the regex is a better option.
For simple use cases String.split() should do the job. If you use guava, there is also a Splitter class which allows chaining of different string operations and supports CharMatcher:
Splitter.on('-')
.trimResults()
.omitEmptyStrings()
.split(string);
The fastest way, which also consumes the least resource could be:
String s = "abc-def";
int p = s.indexOf('-');
if (p >= 0) {
String left = s.substring(0, p);
String right = s.substring(p + 1);
} else {
// s does not contain '-'
}
String Split with multiple characters using Regex
public class StringSplitTest {
public static void main(String args[]) {
String s = " ;String; String; String; String, String; String;;String;String; String; String; ;String;String;String;String";
//String[] strs = s.split("[,\\s\\;]");
String[] strs = s.split("[,\\;]");
System.out.println("Substrings length:"+strs.length);
for (int i=0; i < strs.length; i++) {
System.out.println("Str["+i+"]:"+strs[i]);
}
}
}
Output:
Substrings length:17
Str[0]:
Str[1]:String
Str[2]: String
Str[3]: String
Str[4]: String
Str[5]: String
Str[6]: String
Str[7]:
Str[8]:String
Str[9]:String
Str[10]: String
Str[11]: String
Str[12]:
Str[13]:String
Str[14]:String
Str[15]:String
Str[16]:String
But do not expect the same output across all JDK versions. I have seen one bug which exists in some JDK versions where the first null string has been ignored. This bug is not present in the latest JDK version, but it exists in some versions between JDK 1.7 late versions and 1.8 early versions.
There are only two methods you really need to consider.
Use String.split for a one-character delimiter or you don't care about performance
If performance is not an issue, or if the delimiter is a single character that is not a regular expression special character (i.e., not one of .$|()[{^?*+\) then you can use String.split.
String[] results = input.split(",");
The split method has an optimization to avoid using a regular expression if the delimeter is a single character and not in the above list. Otherwise, it has to compile a regular expression, and this is not ideal.
Use Pattern.split and precompile the pattern if using a complex delimiter and you care about performance.
If performance is an issue, and your delimiter is not one of the above, you should pre-compile a regular expression pattern which you can then reuse.
// Save this somewhere
Pattern pattern = Pattern.compile("[,;:]");
/// ... later
String[] results = pattern.split(input);
This last option still creates a new Matcher object. You can also cache this object and reset it for each input for maximum performance, but that is somewhat more complicated and not thread-safe.
You can split a string by a line break by using the following statement:
String textStr[] = yourString.split("\\r?\\n");
You can split a string by a hyphen/character by using the following statement:
String textStr[] = yourString.split("-");
public class SplitTest {
public static String[] split(String text, String delimiter) {
java.util.List<String> parts = new java.util.ArrayList<String>();
text += delimiter;
for (int i = text.indexOf(delimiter), j=0; i != -1;) {
String temp = text.substring(j,i);
if(temp.trim().length() != 0) {
parts.add(temp);
}
j = i + delimiter.length();
i = text.indexOf(delimiter,j);
}
return parts.toArray(new String[0]);
}
public static void main(String[] args) {
String str = "004-034556";
String delimiter = "-";
String result[] = split(str, delimiter);
for(String s:result)
System.out.println(s);
}
}
Please don't use StringTokenizer class as it is a legacy class that is retained for compatibility reasons, and its use is discouraged in new code. And we can make use of the split method as suggested by others as well.
String[] sampleTokens = "004-034556".split("-");
System.out.println(Arrays.toString(sampleTokens));
And as expected it will print:
[004, 034556]
In this answer I also want to point out one change that has taken place for split method in Java 8. The String#split() method makes use of Pattern.split, and now it will remove empty strings at the start of the result array. Notice this change in documentation for Java 8:
When there is a positive-width match at the beginning of the input
sequence then an empty leading substring is included at the beginning
of the resulting array. A zero-width match at the beginning however
never produces such empty leading substring.
It means for the following example:
String[] sampleTokensAgain = "004".split("");
System.out.println(Arrays.toString(sampleTokensAgain));
we will get three strings: [0, 0, 4] and not four as was the case in Java 7 and before. Also check this similar question.
One way to do this is to run through the String in a for-each loop and use the required split character.
public class StringSplitTest {
public static void main(String[] arg){
String str = "004-034556";
String split[] = str.split("-");
System.out.println("The split parts of the String are");
for(String s:split)
System.out.println(s);
}
}
Output:
The split parts of the String are:
004
034556
import java.io.*;
public class BreakString {
public static void main(String args[]) {
String string = "004-034556-1234-2341";
String[] parts = string.split("-");
for(int i=0;i<parts.length;i++) {
System.out.println(parts[i]);
}
}
}
You can use Split():
import java.io.*;
public class Splitting
{
public static void main(String args[])
{
String Str = new String("004-034556");
String[] SplittoArray = Str.split("-");
String string1 = SplittoArray[0];
String string2 = SplittoArray[1];
}
}
Else, you can use StringTokenizer:
import java.util.*;
public class Splitting
{
public static void main(String[] args)
{
StringTokenizer Str = new StringTokenizer("004-034556");
String string1 = Str.nextToken("-");
String string2 = Str.nextToken("-");
}
}
Here are two ways two achieve it.
WAY 1: As you have to split two numbers by a special character you can use regex
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class TrialClass
{
public static void main(String[] args)
{
Pattern p = Pattern.compile("[0-9]+");
Matcher m = p.matcher("004-034556");
while(m.find())
{
System.out.println(m.group());
}
}
}
WAY 2: Using the string split method
public class TrialClass
{
public static void main(String[] args)
{
String temp = "004-034556";
String [] arrString = temp.split("-");
for(String splitString:arrString)
{
System.out.println(splitString);
}
}
}
You can simply use StringTokenizer to split a string in two or more parts whether there are any type of delimiters:
StringTokenizer st = new StringTokenizer("004-034556", "-");
while(st.hasMoreTokens())
{
System.out.println(st.nextToken());
}
Check out the split() method in the String class on javadoc.
https://docs.oracle.com/javase/7/docs/api/java/lang/String.html#split(java.lang.String)
String data = "004-034556-1212-232-232";
int cnt = 1;
for (String item : data.split("-")) {
System.out.println("string "+cnt+" = "+item);
cnt++;
}
Here many examples for split string but I little code optimized.
String str="004-034556"
String[] sTemp=str.split("-");// '-' is a delimiter
string1=004 // sTemp[0];
string2=034556//sTemp[1];
I just wanted to write an algorithm instead of using Java built-in functions:
public static List<String> split(String str, char c){
List<String> list = new ArrayList<>();
StringBuilder sb = new StringBuilder();
for (int i = 0; i < str.length(); i++){
if(str.charAt(i) != c){
sb.append(str.charAt(i));
}
else{
if(sb.length() > 0){
list.add(sb.toString());
sb = new StringBuilder();
}
}
}
if(sb.length() >0){
list.add(sb.toString());
}
return list;
}
You can use the method split:
public class Demo {
public static void main(String args[]) {
String str = "004-034556";
if ((str.contains("-"))) {
String[] temp = str.split("-");
for (String part:temp) {
System.out.println(part);
}
}
else {
System.out.println(str + " does not contain \"-\".");
}
}
}
To split a string, uses String.split(regex). Review the following examples:
String data = "004-034556";
String[] output = data.split("-");
System.out.println(output[0]);
System.out.println(output[1]);
Output
004
034556
Note:
This split (regex) takes a regex as an argument. Remember to escape the regex special characters, like period/dot.
String s = "TnGeneral|DOMESTIC";
String a[]=s.split("\\|");
System.out.println(a.toString());
System.out.println(a[0]);
System.out.println(a[1]);
Output:
TnGeneral
DOMESTIC
String s="004-034556";
for(int i=0;i<s.length();i++)
{
if(s.charAt(i)=='-')
{
System.out.println(s.substring(0,i));
System.out.println(s.substring(i+1));
}
}
As mentioned by everyone, split() is the best option which may be used in your case. An alternative method can be using substring().

Extract only characters from a string and store it in another string

I have a String, say
String str = "1.) Java is fun. play with 12"
I want everything after ) to be stored as separate String. What is the best way to do it? I tried spliting the string on ")":
String det[] = str.split(")");
But it is giving:
java.util.regex.PatternSyntaxException: Unmatched closing ')'`
Sample input:
String str = "1.) JAVA is fun.Play with 12"
Sample output:
String result = "JAVA is fun.Play with 12"
String.split takes a regex as parameter. ) is a special character for regural expressions so you need to escape it with \. Since in Java \ also needs to be escaped, you need to split with \\).
String str = "1.) Java is fun. play with 12";
String[] tokens = str.split("\\)", 2); // split only in 2 parts
System.out.println(tokens[1]);
Note that in this code, I specified a limit of 2 to the split call. This means that it will split the String in 2 parts only. This is to tackle the case where the String you want to extract might also contain a ), like an input of "1.) Java is fun :). Play with 12".
As a side note, in this case, it would be easier (and perhaps faster) to use substring instead of split, like this:
String str = "1.) Java is fun. play with 12";
String result = str.substring(str.indexOf(')') + 1);
System.out.println(result);
Try to split in this way.
public static void main(String args[]) {
String s = "1.) Java is fun. play with 12";
String[] r = s.split("\\)");
for (int i = 0; i<r.length; i++){
System.out.println(""+r[i]);
}
}
I will do something like this:
String str= "1.) JAVA is fun.Play with 12";
String separateString;
int index = str.indexOf(')');
if (index >= 0) {
separateString = str.substring(index);
}

java StringTokenizer skips the charaters if its part of delimiter

I have issues in using java string tokenizer:
String myString = "1||2||3|||4";
StringTokenizer stp = new StringTokenizer(myString, "||");
while (stp.hasMoreTokens()) {
System.out.println(stp.nextToken());
}
actual output : [1,2,3,4]
expected output : [1,2,3,'|4']
Could any one help me on the same
Try this..
String myString = "1||2||3|||4";
String[] s=myString.split("\\|\\|");
for (String string : s) {
System.err.println(string);
}
I think you cannot do anything because it's how StringTokenizer works (you can put returnDelims true and remove it manually but it's more hard than look sometimes)
String myString = "1||2||3|||4";
String[] tokens = myString.split("\\|\\|");
for(String token : tokens)
{
System.out.println(token);
}
You can use split which does what you want.
Output:
1
2
3
|4
It is recommended to use the split method of the String class for doing this since StringTokenizer matches the given string and split takes a regular expression. I would use this:
String[] splitStr = myString.split("[|]{2}");
This matches every time the regular expression [|] (a single pipe) is matched twice in a row.
You are maybe thinking of String.split, as this splits on a delimiter string.
A StringTokenizer takes the delimiter string and recognizes all characters in it as a delimiter. So in fact you redundantly specified the "|" character a second time.
Using the split function is what you maybe wanted:
System.out.println(Arrays.toString("1||2||3|||4".split("\\|\\|")));
This produces
[1, 2, 3, |4]
take a look this is an easy solution:
StringTokenizer stp = new StringTokenizer(myString, "|");
while (stp.hasMoreTokens()) {
System.out.println(stp.nextToken());
}

explode function in java as in PHP

I have a variable in java, which is like this I+am+good+boy I want to get seperate them on the basis of + , in PHP I can use explode which is very handy, is there any function in java?I saw the split() function definition but that was not helpful.as it take regular expression.
Any help
Thanks
Use String.split() in regards to explode.
An example of use:
Explode :
String[] explode = "I+am+a+good+boy".split("+");
And you can reverse this like so (or "implode" it):
String implode = StringUtils.join(explode[], " ");
You have two options as I know :
String text = "I+am+good+boy";
System.out.println("Using Tokenizer : ");
StringTokenizer tokenizer = new StringTokenizer(text, "+");
while (tokenizer.hasMoreTokens()) {
String token = tokenizer.nextToken();
System.out.println(" Token = " + token);
}
System.out.println("\n Using Split :");
String [] array = text.split("\\+");
for (int i = 0; i < array.length; i++) {
System.out.println(array[i]);
}
You can try like this
String str = "I+am+a+good+boy";
String[] array = str.split("\\+");
you will get "I", "am", "a", "good", "boy" strings in the array. And you can access them as
String firstElem = array[0];
In the firstElem string you will get "I" as result.
The \\ before + because split() takes regular expressions (regex) as argument and regex has special meaning for a +. It means one or more copies of the string trailing the +.
So, if you want to get literal + sign, then you have to use escape char \\.
Just use split and escape the regex - either by hand or using the Pattern.quote() method.
String str = "I+am+a+good+boy";
String[] pieces = str.split("+")
Now you can use pieces[0], pieces[1] and so on.
More Info: http://docs.oracle.com/javase/7/docs/api/java/lang/String.html#split%28java.lang.String%29

regular expression to split the string in java

I want to split the string say [AO_12345678, Real Estate] into AO_12345678 and Real Estate
how can I do this in Java using regex?
main issue m facing is in avoiding "[" and "]"
please help
Does it really have to be regex?
if not:
String s = "[AO_12345678, Real Estate]";
String[] split = s.substring(1, s.length()-1).split(", ");
I'd go the pragmatic way:
String org = "[AO_12345678, Real Estate]";
String plain = null;
if(org.startsWith("[") {
if(org.endsWith("]") {
plain = org.subString(1, org.length());
} else {
plain = org.subString(1, org.length() + 1);
}
}
String[] result = org.split(",");
If the string is always surrounded with '[]' you can just substring it without checking.
One easy way, assuming the format of all your inputs is consistent, is to ignore regex altogether and just split it. Something like the following would work:
String[] parts = input.split(","); // parts is ["[AO_12345678", "Real Estate]"]
String firstWithoutBrace = parts[0].substring(1);
String secondWithoutBrace = parts[1].substring(0, parts[1].length() - 1);
String first = firstWithoutBrace.trim();
String second = secondWithoutBrace.trim();
Of course you can tailor this as you wish - you might want to check whether the braces are present before removing them, for example. Or you might want to keep any spaces before the comma as part of the first string. This should give you a basis to modify to your specific requirements however.
And in a simple case like this I'd much prefer code like the above to a regex that extracted the two strings - I consider the former much clearer!
you can also use StringTokenizer. Here is the code:
String str="[AO_12345678, Real Estate]"
StringTokenizer st=new StringTokenizer(str,"[],",false);
String s1 = st.nextToken();
String s2 = st.nextToken();
s1=AO_12345678
s1=Real Estate
Refer to javadocs for reading about StringTokenizer
http://download.oracle.com/javase/1.4.2/docs/api/java/util/StringTokenizer.html
Another option using regular expressions (RE) capturing groups:
private static void extract(String text) {
Pattern pattern = Pattern.compile("\\[(.*),\\s*(.*)\\]");
Matcher matcher = pattern.matcher(text);
if (matcher.find()) { // or .matches for matching the whole text
String id = matcher.group(1);
String name = matcher.group(2);
// do something with id and name
System.out.printf("ID: %s%nName: %s%n", id, name);
}
}
If speed/memory is a concern, the RE can be optimized to (using Possessive quantifiers instead of Greedy ones)
"\\[([^,]*+),\\s*+([^\\]]*+)\\]"

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