Java remove all characters after a specific character

/**
 * @author lautturi.com 
 * Java example: Java remove all characters after a specific character 
 */

import java.util.*;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class Lautturi {
	public static void main(String[] args) {

		String config = "field=value";
		String str = config.substring(0,config.indexOf("="));
		str.trim();

		System.out.println(str);
	}
}