软件简介

Mozilla在很多年前就做了一个非常优秀的编码检测工具，叫chardet(java版jchardet
)，后来有发布了算法更加优秀的universalchardet，用于Firefox的自动编码识别。另外Apache内容抽取项目Tika的发布包tika-
app-1.*.jar(自1.2及以后版本)其中打包了juniversalchardet。

注意：如果试图识别几个字节的短文本编码，可能会出现了识别错误，这应该是算法实现本身的缺陷，但识别稍大一点文本编码，正确率则非常高，尤其较chardet要高的多。

Encodings that can be detected

• Chinese

  • ISO-2022-CN
  • BIG5
  • EUC-TW
  • GB18030
  • HZ-GB-23121

• Cyrillic

  • ISO-8859-5
  • KOI8-R
  • WINDOWS-1251
  • MACCYRILLIC
  • IBM866
  • IBM855

• Greek

  • ISO-8859-7
  • WINDOWS-1253

• Hebrew

  • ISO-8859-8
  • WINDOWS-1255

• Japanese

  • ISO-2022-JP
  • SHIFT_JIS
  • EUC-JP

• Korean

  • ISO-2022-KR
  • EUC-KR

• Unicode

  • UTF-8
  • UTF-16BE / UTF-16LE
  • UTF-32BE / UTF-32LE / X-ISO-10646-UCS-4-34121 / X-ISO-10646-UCS-4-21431

• Others

  • WINDOWS-1252

Related

Works

jchardet

jchardet is another Java port of the Mozilla’s encoding dectection

library. The main difference between jchardet and juniversalchardet is modules
they are based on. jchardet is based on the ‘chardet’ module that has long
existed. juniversalchardet is based on the ‘universalchardet’ module that is
new and generally provides better accuracy on detection results.

Sample Code

import org.mozilla.universalchardet.UniversalDetector;

public class TestDetector {
  public static void main(String[] args) throws java.io.IOException {
    byte[] buf = new byte[4096];
    String fileName = args[0];
    java.io.FileInputStream fis = new java.io.FileInputStream(fileName);

    // (1)
    UniversalDetector detector = new UniversalDetector(null);

    // (2)
    int nread;
    while ((nread = fis.read(buf)) > 0 && !detector.isDone()) {
      detector.handleData(buf, 0, nread);
    }
    // (3)
    detector.dataEnd();

    // (4)
    String encoding = detector.getDetectedCharset();
    if (encoding != null) {
      System.out.println("Detected encoding = " + encoding);
    } else {
      System.out.println("No encoding detected.");
    }

    // (5)
    detector.reset();
  }
}