In java how to get substring from a string till a character c?

I have a string (which is basically a file name following a naming convention) abc.def.ghi

I would like to extract the substring before the first . (ie a dot)

In java doc api, I can't seem to find a method in String which does that.
Am I missing something? How to do it?

The accepted answer is correct but it doesn't tell you how to use it. This is how you use indexOf and substring functions together.

String filename = "abc.def.ghi";     // full file name
int iend = filename.indexOf("."); //this finds the first occurrence of "." 
//in string thus giving you the index of where it is in the string

// Now iend can be -1, if lets say the string had no "." at all in it i.e. no "." is found. 
//So check and account for it.

String subString;
if (iend != -1) 
{
    subString= filename.substring(0 , iend); //this will give abc
}

You can just split the string..

public String[] split(String regex)

Note that java.lang.String.split uses delimiter's regular expression value. Basically like this...

String filename = "abc.def.ghi";     // full file name
String[] parts = filename.split("\\."); // String array, each element is text between dots

String beforeFirstDot = parts[0];    // Text before the first dot

Of course, this is split into multiple lines for clairity. It could be written as

String beforeFirstDot = filename.split("\\.")[0];

look at String.indexOf and String.substring.

Make sure you check for -1 for indexOf.

If your project already uses commons-lang, StringUtils provide a nice method for this purpose:

String filename = "abc.def.ghi";

String start = StringUtils.substringBefore(filename, "."); // returns "abc"

see javadoc [2.6] [3.1]

or you may try something like

"abc.def.ghi".substring(0,"abc.def.ghi".indexOf(c)-1);

How about using regex?

String firstWord = filename.replaceAll("\\..*","")

This replaces everything from the first dot to the end with "" (ie it clears it, leaving you with what you want)

Here's a test:

System.out.println("abc.def.hij".replaceAll("\\..*", "");

Output:

abc

public void getStrings() {
	String params = "abc.def.ghi";
	String s1, s2, s3;
	s1 = params.substring(0, params.indexOf("."));
	params = params.substring(params.indexOf(".") + 1);
	s2 = params.substring(0, params.indexOf("."));
	params = params.substring(params.indexOf(".") + 1, params.length());
	s3 = params;
}

the solution

> s1="abc" s2="def" s3="ghi"

IF you have more than 3 String , so then it will look exactly like s2

In java.lang.String you get some methods like indexOf(): which returns you first index of a char/string. and lstIndexOf: which returns you the last index of String/char

From Java Doc:

  public int indexOf(int ch)
  public int indexOf(String str)

Returns the index within this string of the first occurrence of the specified character.

Here is code which returns a substring from a String until any of a given list of characters:

/**
 * Return a substring of the given original string until the first appearance
 * of any of the given characters.
 * <p>
 * e.g. Original "ab&cd-ef&gh"
 * 1. Separators {'&', '-'}
 * Result: "ab"
 * 2. Separators {'~', '-'}
 * Result: "ab&cd"
 * 3. Separators {'~', '='}
 * Result: "ab&cd-ef&gh"
 *
 * @param original   the original string
 * @param characters the separators until the substring to be considered
 * @return the substring or the original string of no separator exists
 */
public static String substringFirstOf(String original, List<Character> characters) {
    return characters.stream()
            .map(original::indexOf)
            .filter(min -> min > 0)
            .reduce(Integer::min)
            .map(position -> original.substring(0, position))
            .orElse(original);
}

This could help:

public static String getCorporateID(String fileName) {

	String corporateId = null;

	try {
		corporateId = fileName.substring(0, fileName.indexOf("_"));
		// System.out.println(new Date() + ": " + "Corporate:
		// "+corporateId);
		return corporateId;
	} catch (Exception e) {
		corporateId = null;
		e.printStackTrace();
	}

	return corporateId;
}

  private String getTextBefore(final String wholeString, String before){
   final int indexOf = wholeString.indexOf(before); 
   if(indexOf != -1){
       return wholeString.substring(0, indexOf);
   }
   return wholeString;
}

I tried something like this,

String str = "abc.def.ghi";
String strBeforeFirstDot = str.substring(0, str.indexOf('.'));
// strBeforeFirstDot = "abc"

I tried for my example, to extract all char before @ sign in email to extract and provide a username.