Java中全角/半角字符的转换

在处理字符串时，经常需要进行全角/半角字符的转换，其实原理非常简单，只要得出字母的偏移值，重新计算其编码即可，下面给出转换方法

    public String toDBCS(String str) {

        if (str == null) {

            return "";

        }

 

        StringBuffer sb = new StringBuffer();

 

        for (int i = 0, n = str.length(); i< n; i++) {

            int c = str.charAt(i);

 

            if ((c >= 'a') && (c<= 'z')) {

                c = (c + 'ａ') - 'a';

            } else if ((c >= 'A') &&(c <= 'Z')) {

                c = (c + 'Ａ') - 'A';

            } else if ((c >= '0') &&(c <= '9')) {

                c = (c + '０') - '0';

            }

 

            sb.append((char) c);

        }

 

        return sb.toString();

    }

 

    public String toSBCS(String str) {

        if (str == null) {

            return "";

        }

 

        StringBuffer sb = new StringBuffer();

 

        for (int i = 0, n = str.length(); i< n; i++) {

            int c = str.charAt(i);

 

            if ((c >= 'Ａ') && (c <= 'Ｚ')) {

                c = (c + 'A') - 'Ａ';

            } else if ((c >= '０') && (c <= '９')) {

                c = (c + '0') - '０';

            } else if ((c >= 'ａ') && (c <= 'ｚ')) {

                c = (c + 'a') - 'ａ';<
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p>
            }

 

            sb.append((char) c);

        }

 

        return sb.toString();

    }