Java 常用字串操作總結

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1. String轉ASCII碼

    public static String stringToAscii(String value) {        StringBuffer sbu = new StringBuffer();        char[] chars = value.toCharArray();        for (int i = 0; i < chars.length; i++) {            if (i <= chars.length - 1) {                int ii = chars[i];                sbu.append(Integer.toHexString(ii));            } else {                sbu.append((int) chars[i]);            }        }        return sbu.toString();    } 

2. ASCII碼轉String

    public static String asciiToString(String value) {        if("".equals(value) || value == null){            return "";        }        StringBuffer sBuffer = new StringBuffer();        char[] chars = value.toCharArray();        for (int i = 0; i < chars.length; i = i + 2) {            if (i < chars.length - 1) {                int ii = Integer.valueOf(                    Character.toString(chars[i]) + Character.toString(chars[i + 1]), 16);                sBuffer.append((char) (ii));            }        }        return sBuffer.toString();    }

 

3. 輸入資料流轉位元組數組

    public static String inputStream2Byte(InputStream inputStream) throws IOException {        ByteArrayOutputStream bos = new ByteArrayOutputStream();        byte[] buffer = new byte[1024];        int len = -1;        while ((len = inputStream.read(buffer)) != -1) {            bos.write(buffer, 0, len);        }        bos.close();        return new String(bos.toByteArray(), "UTF-8");    }

4. 輸入資料流轉字串

 

    public static String InputStreamTOString(InputStream in) throws Exception {                ByteArrayOutputStream outStream = new ByteArrayOutputStream();        byte[] data = new byte[1024];        int count = -1;        while ((count = in.read(data, 0, 2048)) != -1)            outStream.write(data, 0, count);                data = null;        return new String(outStream.toByteArray());    }

　

5. 判斷輸入是不是包含中文

    public static boolean isChinese(char c) {        Character.UnicodeBlock ub = Character.UnicodeBlock.of(c);        if (ub == Character.UnicodeBlock.CJK_UNIFIED_IDEOGRAPHS || ub == Character.UnicodeBlock.CJK_COMPATIBILITY_IDEOGRAPHS                || ub == Character.UnicodeBlock.CJK_UNIFIED_IDEOGRAPHS_EXTENSION_A || ub == Character.UnicodeBlock.CJK_UNIFIED_IDEOGRAPHS_EXTENSION_B                || ub == Character.UnicodeBlock.CJK_SYMBOLS_AND_PUNCTUATION || ub == Character.UnicodeBlock.HALFWIDTH_AND_FULLWIDTH_FORMS                || ub == Character.UnicodeBlock.GENERAL_PUNCTUATION) {            return true;        }        return false;    }     public static boolean isChinese(String strName) {        char[] ch = strName.toCharArray();        for (int i = 0; i < ch.length; i++) {            char c = ch[i];            if (isChinese(c)) {                return true;            }        }        return false;    }

　　

6. 檢驗子網路遮罩的合法性：子網路遮罩轉化為二進位之後不能全是1，也不能全是0，必須是連續的1或者連續的0，也就是說1和0不能交替出現。

　 實現方式，先將4個整數欄位按照每八位拼接起來，軟後轉化為二進位顯示方式，使用Regex進行匹配。

    public static boolean checkMask(String maskStr){        String[] ips = maskStr.split("\\.");          String binaryVal = "";          for (int i = 0; i < ips.length; i++)          {              String binaryStr = Integer.toBinaryString(Integer.parseInt(ips[i]));                Integer times = 8 - binaryStr.length();                            for(int j = 0; j < times; j++)              {                  binaryStr = "0" +  binaryStr;  //補齊八位，每次需要進行八位合并            }              binaryVal += binaryStr;          }          Pattern regxPattern = Pattern.compile("^[1]*[0]*$");        if(regxPattern.matcher(binaryVal).matches())          {              return true;          }else {            return false;        }    }

 

7. 檢查IP的合法性，並轉化為整數表示

    public static boolean validIP(String ip) {        if (ip == null) {            return false;        }　　　　 String IP_REGEX  = "\\b((?!\\d\\d\\d)\\d+|1\\d\\d|2[0-4]\\d|25[0-5])\\."                                                       + "((?!\\d\\d\\d)\\d+|1\\d\\d|2[0-4]\\d|25[0-5])\\."                                                       + "((?!\\d\\d\\d)\\d+|1\\d\\d|2[0-4]\\d|25[0-5])\\."                                                       + "((?!\\d\\d\\d)\\d+|1\\d\\d|2[0-4]\\d|25[0-5])\\b";        Pattern     ipPattern           = Pattern.compile(IP_REGEX);        Matcher matcher = ipPattern.matcher(ip);        return matcher.matches();    }    public static Integer ipString2Int(String strIp){        if(!validIP(strIp)) return null;        int[] ip = new int[4];        String[] ips = strIp.split("\\.");        ip[0] = Integer.parseInt(ips[0]);        ip[1] = Integer.parseInt(ips[1]);        ip[2] = Integer.parseInt(ips[2]);        ip[3] = Integer.parseInt(ips[3]);        return (ip[0] << 24) + (ip[1] << 16) + (ip[2] << 8) + ip[3];    }

　　

　　

 

　　

 

Java 常用字串操作總結