java 中 16 进制 HEX 转换成字节码形式的 UTF-8

import java.io.UnsupportedEncodingException;
import java.math.BigInteger;

public class Test {

	public static String str2Hex(String str) throws UnsupportedEncodingException {
		String hexRaw = String.format("%x", new BigInteger(1, str.getBytes("UTF-8")));
		char[] hexRawArr = hexRaw.toCharArray();
		StringBuilder hexFmtStr = new StringBuilder();
		final String SEP = "\\x";
		for (int i = 0; i < hexRawArr.length; i++) {
			hexFmtStr.append(SEP).append(hexRawArr[i]).append(hexRawArr[++i]);
		}
		return hexFmtStr.toString();
	}

	public static String hex2Str(String str) throws UnsupportedEncodingException {
		String strArr[] = str.split("\\\\"); // 分割拿到形如 xE9 的16进制数据
		byte[] byteArr = new byte[strArr.length - 1];
		for (int i = 1; i < strArr.length; i++) {
			Integer hexInt = Integer.decode("0" + strArr[i]);
			byteArr[i - 1] = hexInt.byteValue();
		}

		return new String(byteArr, "UTF-8");
	}

	public static void main(String[] args) throws UnsupportedEncodingException {

		System.out.println(str2Hex("中国1a23"));
		System.out.println(hex2Str(str2Hex("中国1a23")));
		System.out.println(hex2Str("\\xE9\\xBB\\x84\\xE8\\x8A\\xB1\\xE6\\xA2\\xA8\\xE5\\xAE\\xB6\\xE5\\x85\\xB7\\xE8\\xBD\\xAC\\xE8\\xAE\\xA9"));
	}

}

\xe4\xb8\xad\xe5\x9b\xbd\x31\x61\x32\x33
中国1a23
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String string = "中国\u6211\u7231\u5317\u4EAC";
byte[] utf8 = string.getBytes("UTF-8");
string = new String(utf8, "UTF-8");
System.out.println(string);