如何解码为UTF-8字符串从十六进制编码字符串

Question

我得到的HTML JavaScript字符串，如：

htmlString = "https\x3a\x2f\x2ftest.com" 

但我想下面将其解码：

str = "https://test.com" 

这意味着，我想要一个Util API：

public static String decodeHex(String htmlString){ 
    // do decode and converter here 
} 

public static void main(String ...args){ 
     String htmlString = "https\x3a\x2f\x2ftest.com"; 
     String str = decodeHex(htmlString); 
     // str should be "https://test.com" 
} 

有没有人知道如何实现这个API - decodeHex？

Answer 1

这应该足以让你开始。我离开实施hexDecode并将错误的输入作为练习来排序。

public String decode(String encoded) { 
    StringBuilder sb = new StringBuilder(); 
    for (int i = 0; i < encoded.length(); i++) { 
    if (encoded.charAt(i) == '\' && (i + 3) < encoded.length() && encoded.charAt(i + 1) == 'x') { 
     sb.append(hexDecode(encoded.substring(i + 2, i + 4))); 
     i += 3; 
    } else { 
     sb.append(encoded.charAt(i)); 
    } 
    } 
    return sb.toString; 
} 

Answer 2

public String decode(String encoded) throws DecoderException { 
     StringBuilder sb = new StringBuilder(); 
     for (int i = 0; i < encoded.length(); i++) { 
     if (encoded.charAt(i) == '\\' && (i + 3) < encoded.length() && encoded.charAt(i + 1) == 'x') { 
      sb.append(new String(Hex.decodeHex(encoded.substring(i + 2, i + 4).toCharArray()),StandardCharsets.UTF_8)); 
      i += 3; 
     } else { 
      sb.append(encoded.charAt(i)); 
     } 
     } 
     return sb.toString(); 
    }