1 public static String removeStr(String src, String str) { 2         if (src =http://www.mamicode.com/= null || str == null) return src; 3         int idx = src.indexOf(str); 4         if (idx == -1) return src; 5         int pst = 0; 6         char[] cs = src.toCharArray(); 7         char[] rs = new char[src.length() - str.length()]; 8         for (int i = 0; i < cs.length; i ++) { 9             if (i >= idx && i < idx + str.length()) continue;10             rs[pst] = cs[i];11             pst ++;12         }13         return new String(rs);14     }15     public static String replaceStr(String src, String target, String replacement) {16         if (src =http://www.mamicode.com/= null || target == null || replacement == null) return src;17         int idx = src.indexOf(target);18         if (idx == -1) return src;19         int pst = 0;20         char[] cs = src.toCharArray();21         char[] rs = new char[src.length() - target.length() + replacement.length()];22         for (int i = 0; i < cs.length; i ++) {23             if (i == idx) {24                 for (char c : replacement.toCharArray()) {25                     rs[pst] = c;26                     pst ++;27                 }28                 continue;29             }30             if (i > idx && i < idx + target.length()) continue;31             rs[pst] = cs[i];32             pst ++;33         }34         return new String(rs);35     }36     /**37      * 38      * @param src39      * @param target40      * @param replacement41      * @return42      */43     public static String replaceAllStr(String src, String target, String replacement) {44         if (src =http://www.mamicode.com/= null || target == null || replacement == null) return src;45         int idx = src.indexOf(target);46         if (idx == -1) return src;47         int pst = 0;48         char[] cs = src.toCharArray();49         char[] rs = new char[src.length() - target.length() + replacement.length()];50         for (int i = 0; i < cs.length; i ++) {51             if (i == idx) {52                 for (char c : replacement.toCharArray()) {53                     rs[pst] = c;54                     pst ++;55                 }56                 continue;57             }58             if (i > idx && i < idx + target.length()) continue;59             rs[pst] = cs[i];60             pst ++;61         }62         return replaceAllStr(new String(rs), target, replacement);63     }