Gets len characters from the middle of a String - Android java.lang

Android examples for java.lang:String Substring

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Description

Gets len characters from the middle of a String

Demo Code

import java.io.UnsupportedEncodingException;
import java.nio.charset.Charset;
import java.text.Normalizer;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;
import java.util.Locale;
import java.util.regex.Pattern;

public class Main{

    /**// w ww  . ja v  a2 s .  co  m
     * <p>Gets {@code len} characters from the middle of a String.</p>
     *
     * <p>If {@code len} characters are not available, the remainder
     * of the String will be returned without an exception. If the
     * String is {@code null}, {@code null} will be returned.
     * An empty String is returned if len is negative or exceeds the
     * length of {@code str}.</p>
     *
     * <pre>
     * StringUtils.mid(null, *, *)    = null
     * StringUtils.mid(*, *, -ve)     = ""
     * StringUtils.mid("", 0, *)      = ""
     * StringUtils.mid("abc", 0, 2)   = "ab"
     * StringUtils.mid("abc", 0, 4)   = "abc"
     * StringUtils.mid("abc", 2, 4)   = "c"
     * StringUtils.mid("abc", 4, 2)   = ""
     * StringUtils.mid("abc", -2, 2)  = "ab"
     * </pre>
     *
     * @param str  the String to get the characters from, may be null
     * @param pos  the position to start from, negative treated as zero
     * @param len  the length of the required String
     * @return the middle characters, {@code null} if null String input
     */
    public static String mid(final String str, int pos, final int len) {
        if (str == null) {
            return null;
        }
        if (len < 0 || pos > str.length()) {
            return "";
        }
        if (pos < 0) {
            pos = 0;
        }
        if (str.length() <= pos + len) {
            return str.substring(pos);
        }
        return str.substring(pos, pos + len);
    }

}

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