replace a String by Char - Java java.lang

Java examples for java.lang:String Replace

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Description

replace a String by Char

Demo Code


//package com.java2s;

public class Main {
    public static void main(String[] argv) {
        String str = "java2s.com";
        char searchChar = 'a';
        char replaceChar = 'a';
        System.out.println(replaceChars(str, searchChar, replaceChar));
    }/*  www .  j  ava 2  s.  com*/

    public static final String EMPTY_STRING = "";

    public static String replaceChars(String str, char searchChar,
            char replaceChar) {
        if (str == null) {
            return null;
        }

        return str.replace(searchChar, replaceChar);
    }

    public static String replaceChars(String str, String searchChars,
            String replaceChars) {
        if ((str == null) || (str.length() == 0) || (searchChars == null)
                || (searchChars.length() == 0)) {
            return str;
        }

        char[] chars = str.toCharArray();
        int len = chars.length;
        boolean modified = false;

        for (int i = 0, isize = searchChars.length(); i < isize; i++) {
            char searchChar = searchChars.charAt(i);

            if ((replaceChars == null) || (i >= replaceChars.length())) {
                // ??
                int pos = 0;

                for (int j = 0; j < len; j++) {
                    if (chars[j] != searchChar) {
                        chars[pos++] = chars[j];
                    } else {
                        modified = true;
                    }
                }

                len = pos;
            } else {
                // ????
                for (int j = 0; j < len; j++) {
                    if (chars[j] == searchChar) {
                        chars[j] = replaceChars.charAt(i);
                        modified = true;
                    }
                }
            }
        }

        if (!modified) {
            return str;
        }

        return new String(chars, 0, len);
    }

    public static String replace(String text, String repl, String with) {
        return replace(text, repl, with, -1);
    }

    public static String replace(String text, String repl, String with,
            int max) {
        if ((text == null) || (repl == null) || (with == null)
                || (repl.length() == 0) || (max == 0)) {
            return text;
        }

        StringBuffer buf = new StringBuffer(text.length());
        int start = 0;
        int end = 0;

        while ((end = text.indexOf(repl, start)) != -1) {
            buf.append(text.substring(start, end)).append(with);
            start = end + repl.length();

            if (--max == 0) {
                break;
            }
        }

        buf.append(text.substring(start));
        return buf.toString();
    }

    public static int indexOf(String str, char searchChar) {
        if ((str == null) || (str.length() == 0)) {
            return -1;
        }

        return str.indexOf(searchChar);
    }

    public static int indexOf(String str, char searchChar, int startPos) {
        if ((str == null) || (str.length() == 0)) {
            return -1;
        }

        return str.indexOf(searchChar, startPos);
    }

    public static int indexOf(String str, String searchStr) {
        if ((str == null) || (searchStr == null)) {
            return -1;
        }

        return str.indexOf(searchStr);
    }

    public static int indexOf(String str, String searchStr, int startPos) {
        if ((str == null) || (searchStr == null)) {
            return -1;
        }

        // JDK1.3????????bug?????????????????
        if ((searchStr.length() == 0) && (startPos >= str.length())) {
            return str.length();
        }

        return str.indexOf(searchStr, startPos);
    }

    public static String substring(String str, int start) {
        if (str == null) {
            return null;
        }

        if (start < 0) {
            start = str.length() + start;
        }

        if (start < 0) {
            start = 0;
        }

        if (start > str.length()) {
            return EMPTY_STRING;
        }

        return str.substring(start);
    }

    public static String substring(String str, int start, int end) {
        if (str == null) {
            return null;
        }

        if (end < 0) {
            end = str.length() + end;
        }

        if (start < 0) {
            start = str.length() + start;
        }

        if (end > str.length()) {
            end = str.length();
        }

        if (start > end) {
            return EMPTY_STRING;
        }

        if (start < 0) {
            start = 0;
        }

        if (end < 0) {
            end = 0;
        }

        return str.substring(start, end);
    }
}

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