Jakarta Commons Codec 使用指南：Base64、Hex、Metaphone/Soundex 編碼實戰

功能概覽

• Base64 / Hex：二進制↔文本編碼，傳輸存儲通用
• Metaphone / Soundex：發音編碼，模糊匹配、去重、語音搜索核心

Maven 依賴

<dependency>
  <groupId>commons-codec</groupId>
  <artifactId>commons-codec</artifactId>
  <version>1.11</version>
</dependency>

Base64 編解碼

Base64 codec = new Base64();
String original = "中文";

byte[] encoded = codec.encode(original.getBytes("UTF-8"));
String encodedStr = new String(encoded); // 5bCP5piO

byte[] decoded = codec.decode(encoded);
String decodedStr = new String(decoded, "UTF-8"); // 中文

System.out.println("編碼前: " + original);
System.out.println("編碼後: " + encodedStr);
System.out.println("解碼後: " + decodedStr);

Hex 編解碼

Hex codec = new Hex();
String original = "中文";

char[] encoded = codec.encodeHex(original.getBytes("UTF-8"));
String encodedStr = new String(encoded); // e4b8ade69687

byte[] decoded = codec.decodeHex(encoded);
String decodedStr = new String(decoded, "UTF-8"); // 中文

System.out.println("編碼前: " + original);
System.out.println("編碼後: " + encodedStr);
System.out.println("解碼後: " + decodedStr);

發音編碼：Metaphone、RefinedSoundex、Soundex

Metaphone metaphone = new Metaphone();
RefinedSoundex refined = new RefinedSoundex();
Soundex soundex = new Soundex();

String[] words = {"resume", "resin"};
for (String w : words) {
    System.out.println("Original: " + w);
    System.out.println("Metaphone: " + metaphone.encode(w));       // RS / RSN
    System.out.println("RefinedSoundex: " + refined.encode(w)); // R250 / R250
    System.out.println("Soundex: " + soundex.encode(w));         // R250 / R250
    System.out.println();
}

算法特性對比

Metaphone 為同音詞生成相同鍵值，比 Soundex 準確，但無固定長度。選型視業務容錯率而定。