如何检查字符是否来自 Java 中的特定字符集？

Question

我有一种方法可以将文件中的一行从给定字符集（utf-8 或 latin1）转换为另一个字符集。从 utf-8 转换为 latin1 时，我应该只显示无法转换的字符（因为这是尝试从 utf-8 转换为 latin1 时发生的情况）。我有兴趣检查单个字符是如何被翻译或未被翻译的。

 private String transcodeLineFromTo(String string, Charset fromCharset, Charset toCharset) {
        try {
            ByteBuffer inputBuffer = ByteBuffer.wrap(string.getBytes(fromCharset));
            CharBuffer data = fromCharset.decode(inputBuffer);
            ByteBuffer outputBuffer = toCharset.encode(data);

            byte[] outputData = outputBuffer.array();
            String originalLine  = new String(outputData);
            String convertedLine = new String(outputData, toCharset);
            StringBuilder notEncoded = new StringBuilder();
            char[] lineCharacters = convertedLine.toCharArray();
            for (char ch : lineCharacters) {
                if () {
                    notEncoded.append();
                }
            }
            if (!notEncoded.toString().equals("")) {
                return notEncoded.toString();
            } else {
                return convertedLine;
            }
        } catch (Exception e) {
            throw new IllegalStateException(e);
        }
    }

Answer 1

您可以通过调用 Charset canEncode 函数来检查编码是否可行。试试这个：

private String transcodeLineFromTo(String string, Charset fromCharset, Charset toCharset) {
        try {
            StringBuilder notEncoded = new StringBuilder();
            char[] lineCharacters = string.toCharArray();
            for (char ch : lineCharacters) {
                if (!toCharset.newEncoder().canEncode(ch)) {
                    notEncoded.append(ch);
                }
            }
            if (!notEncoded.toString().equals("")) {
                return notEncoded.toString();
            } else {
                return new String(toCharset.newEncoder().encode(fromCharset.decode(ByteBuffer.wrap(string.getBytes(fromCharset)))).array(),toCharset);
            }
        } catch (Exception e) {
            throw new IllegalStateException(e);
        }
    }

如何检查字符是否来自 Java 中的特定字符集？

How to check if a character is from a specific charset in Java?

java

string

utf-8

iso-8859-1