source: java/main/src/main/java/com/framsticks/util/lang/Strings.java @ 193

package com.framsticks.util.lang;

import java.util.regex.Matcher;

import com.framsticks.util.FramsticksException;

/**
 * @author Piotr Sniegowski
 */
public abstract class Strings {

        public static String valueOf(Object o) {
                if (o == null) {
                        return null;
                }
                return o.toString();
        }

        public static boolean notEmpty(String str) {
                return str != null && !str.equals("");
        }

        public static void assureNotEmpty(String str) {
                if (!notEmpty(str)) {
                        throw new FramsticksException().msg("string is empty");
                }
        }

        public static String toStringNullProof(Object object) {
                return toStringNullProof(object, "");
        }

        public static String toStringNullProof(Object object, String def) {
                if (object == null) {
                        return def;
                }
                return object.toString();
        }

        public static String toStringEmptyProof(Object object, Object def) {
                if (object == null) {
                        return def.toString();
                }
                String v = object.toString();
                return notEmpty(v) ? v : def.toString();
        }

        public static String collapse(String s) {
                if (s == null) {
                        return null;
                }
                s = s.trim();
                return (s.equals("")) ? null : s;
        }

        public static Pair<String, String> splitIntoPair(String string, char separator, String second) {
                int pos = string.indexOf(separator);
                if (pos == -1) {
                        return new Pair<String, String>(string, second);
                } else {
                        return new Pair<String, String>(string.substring(0, pos), string.substring(pos + 1));
                }
        }

        public static String capitalize(String input) {
                return input.substring(0, 1).toUpperCase() + input.substring(1);
        }

        public static String uncapitalize(String input) {
                return input.substring(0, 1).toLowerCase() + input.substring(1);
        }

        public static String commonPrefix(String a, String b) {
                int length = Math.min(a.length(), b.length());
                int i = 0;
                while ((i < length) && (a.charAt(i) == b.charAt(i))) {
                        ++i;
                }
                return a.substring(0, i);
        }

        public static CharSequence takeGroup(CharSequence input, Matcher matcher, int group) {
                // return (matcher.start(group) == matcher.end(group)) ? null : input.subSequence(matcher.start(group), matcher.end(group));
                return input.subSequence(matcher.start(group), matcher.end(group));
        }

}