Java文件编码从ANSI到UTF8的转换

Question

我需要将文件的编码从 ANSI(windows-1252) 更改为 UTF8。我写了下面的程序来通过 java 来完成它。该程序将字符转换为 UTF8，但是当我在 Notepad++ 中打开文件时，编码类型显示为 ANSI 作为 UTF8。当我在访问数据库中导入此文件时，这给了我错误。需要仅使用 UTF8 编码的文件。此外，要求是在不在任何编辑器中打开文件的情况下转换文件。

public class ConvertFromAnsiToUtf8 {

    private static final char BYTE_ORDER_MARK = '\uFEFF';
    private static final String ANSI_CODE = "windows-1252";
    private static final String UTF_CODE = "UTF8";
    private static final Charset ANSI_CHARSET = Charset.forName(ANSI_CODE);

    public static void main(String[] args) {

        List<File> fileList;
        File inputFolder = new File(args[0]);
        if (!inputFolder.isDirectory()) {
            return;
        }
        File parentDir = new File(inputFolder.getParent() + "\\"
                    + inputFolder.getName() + "_converted");

        if (parentDir.exists()) {
            return;
        }
        if (parentDir.mkdir()) {

        } else {
            return;
        }

        fileList = new ArrayList<File>();
        for (final File fileEntry : inputFolder.listFiles()) {
            fileList.add(fileEntry);
        }

        InputStream in;

        Reader reader = null;
        Writer writer = null;
        try {
            for (File file : fileList) {
                in = new FileInputStream(file.getAbsoluteFile());
                reader = new InputStreamReader(in, ANSI_CHARSET);

                OutputStream out = new FileOutputStream(
                            parentDir.getAbsoluteFile() + "\\"
                                            + file.getName());
                writer = new OutputStreamWriter(out, UTF_CODE);
                writer.write(BYTE_ORDER_MARK);
                char[] buffer = new char[10];
                int read;
                while ((read = reader.read(buffer)) != -1) {
                    System.out.println(read);
                    writer.write(buffer, 0, read);
                }
            }
            reader.close();
            writer.close();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

任何指针都会有所帮助。

谢谢，阿希什

Answer 1

发布的代码正确地从 windows-1252 转码为 UTF-8。

Notepad++ 消息令人困惑，因为“ANSI as UTF-8”没有明显的含义；它似乎是一个 open defect在 Notepad++ 中。我相信 Notepad++ 意味着 没有 BOM 的 UTF-8(请参阅编码菜单。)

作为 Windows 程序的 Microsoft Access 可能希望 UTF-8 文件以字节顺序标记 ( BOM ) 开头。

您可以通过在文件开头写入代码点 U+FEFF 将 BOM 注入(inject)到文档中:

import java.io.*;
import java.nio.charset.*;

public class Ansi1252ToUtf8 {
  private static final char BYTE_ORDER_MARK = '\uFEFF';

  public static void main(String[] args) throws IOException {
    Charset windows1252 = Charset.forName("windows-1252");
    try (InputStream in = new FileInputStream(args[0]);
        Reader reader = new InputStreamReader(in, windows1252);
        OutputStream out = new FileOutputStream(args[1]);
        Writer writer = new OutputStreamWriter(out, StandardCharsets.UTF_8)) {
      writer.write(BYTE_ORDER_MARK);
      char[] buffer = new char[1024];
      int read;
      while ((read = reader.read(buffer)) != -1) {
        writer.write(buffer, 0, read);
      }
    }
  }
}