（转载）JAVA全角半角转换

转自：http://blog.youkuaiyun.com/wanghangzhou1984/article/details/5950440

import java.io.UnsupportedEncodingException;

public class FullCharConverter {
	public static void main(String[] args) throws UnsupportedEncodingException {
		// 全角转半角
		String QJstr = "hello!！ 全角转换，ＤＡＯ ５３２３２　";
		String result = full2HalfChange(QJstr);
		System.out.println(QJstr);
		System.out.println(result);
		System.out.println("------------------------------------");
		// 半角转全角
		String str = "java 汽车 召回 2345";
		System.out.println(str);
		System.out.println(half2Fullchange(str));
	}

	// 全角转半角的 转换函数
	public static final String full2HalfChange(String QJstr)
			throws UnsupportedEncodingException {
		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;
			}
			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);
			}
		} // end for.
		return outStrBuf.toString();
	}

	// 半角转全角
	public static final String half2Fullchange(String QJstr)
			throws UnsupportedEncodingException {
		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;
			}
			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();
	}
}