java 字符串处理(全角转半角，半角转换全角)

第一种方法:

/**
 * 特殊字符串转换
 * @Class Name FullCharConverter
 * @Author v-jiangwei
 * @Create In 2012-8-24
 */
public class FullCharConverter {

/**
* 全角转半角的 转换函数
* @Methods Name full2HalfChange
* @Create In 2012-8-24 By v-jiangwei
* @param QJstr
* @return String
*/
public static final String full2HalfChange(String QJstr)
{
StringBuffer outStrBuf = new StringBuffer("");
String Tstr = "";
byte[] b = null;
for (int i = 0; i < QJstr.length(); i++) {
Tstr = QJstr.substring(i, i + 1);
// 全角空格转换成半角空格
if (Tstr.equals("　")) {
outStrBuf.append(" ");
continue;
}
try {
b = Tstr.getBytes("unicode");
// 得到 unicode 字节数据
if (b[2] == -1) {
// 表示全角
b[3] = (byte) (b[3] + 32);
b[2] = 0;
outStrBuf.append(new String(b, "unicode"));
} else {
outStrBuf.append(Tstr);
}
} catch (UnsupportedEncodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

} // end for.
return outStrBuf.toString();


}



/**
* 半角转全角
* @Methods Name half2Fullchange
* @Create In 2012-8-24 By v-jiangwei
* @param QJstr
* @return String
*/
public static final String half2Fullchange(String QJstr)
{
StringBuffer outStrBuf = new StringBuffer("");
String Tstr = "";
byte[] b = null;
for (int i = 0; i < QJstr.length(); i++) {
Tstr = QJstr.substring(i, i + 1);
if (Tstr.equals(" ")) {
// 半角空格
outStrBuf.append(Tstr);
continue;
}
try {
b = Tstr.getBytes("unicode");
if (b[2] == 0) {
// 半角
b[3] = (byte) (b[3] - 32);
b[2] = -1;
outStrBuf.append(new String(b, "unicode"));
} else {
outStrBuf.append(Tstr);
}
return outStrBuf.toString();
} catch (UnsupportedEncodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

}
return outStrBuf.toString();
}


/**
* @Methods Name main
* @Create In 2012-8-24 By v-jiangwei
* @param args
*            void
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
String QJstr = "８１４乡道";
String result = FullCharConverter.full2HalfChange(QJstr);
System.out.println(QJstr);
System.out.println(result);
System.out.println("------------------------------------");
// 半角转全角
String str = "G45大广高速";
System.out.println(str);
System.out.println(FullCharConverter.half2Fullchange(str));
}


}

第二种方法:

/**
     * 半角转全角
     * @param input String.
     * @return 全角字符串.
     */
public static String ToSBC(String input) {
         char c[] = input.toCharArray();
         for (int i = 0; i < c.length; i++) {
           if (c[i] == ' ') {
             c[i] = '\u3000';
           } else if (c[i] < '\177') {
             c[i] = (char) (c[i] + 65248);


           }
         }
         return new String(c);
}
 
     /**
     * 全角转半角
     * @param input String.
     * @return 半角字符串
     */
 public static String ToDBC(String input) {
     char c[] = input.toCharArray();
          for (int i = 0; i < c.length; i++) {
            if (c[i] == '\u3000') {
              c[i] = ' ';
            } else if (c[i] > '\uFF00' && c[i] < '\uFF5F') {
              c[i] = (char) (c[i] - 65248);


            }
          }
          String returnString = new String(c);
          return returnString;
 }
    public static void main(String[] args) {
    String QJstr = "Ｇ４５大广高速";
String result = StringUtil.ToDBC(QJstr);
System.out.println(result);

}