java：如何将文件转换为utf8

Question

我有一个文件有一些非utf8 caracters（如“ISO-8859-1”），所以我想将该文件（或读取）转换为UTF8编码，我该怎么做？

它是这样的代码：

File file = new File("some_file_with_non_utf8_characters.txt");

/* some code to convert the file to an utf8 file */

...

编辑：放一个编码示例

Answer 1

以下代码将文件从srcEncoding转换为tgtEncoding：

public static void transform(File source, String srcEncoding, File target, String tgtEncoding) throws IOException {
    BufferedReader br = null;
    BufferedWriter bw = null;
    try{
        br = new BufferedReader(new InputStreamReader(new FileInputStream(source),srcEncoding));
        bw = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(target), tgtEncoding));
        char[] buffer = new char[16384];
        int read;
        while ((read = br.read(buffer)) != -1)
            bw.write(buffer, 0, read);
    } finally {
        try {
            if (br != null)
                br.close();
        } finally {
            if (bw != null)
                bw.close();
        }
    }
}

- 编辑 -

使用Try-with-resources（Java 7）：

public static void transform(File source, String srcEncoding, File target, String tgtEncoding) throws IOException {
    try (
      BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream(source), srcEncoding));
      BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(target), tgtEncoding)); ) {
          char[] buffer = new char[16384];
          int read;
          while ((read = br.read(buffer)) != -1)
              bw.write(buffer, 0, read);
    } 
}

Answer 2

  String charset = "ISO-8859-1"; // or what corresponds
  BufferedReader in = new BufferedReader( 
      new InputStreamReader (new FileInputStream(file), charset));
  String line;
  while( (line = in.readLine()) != null) { 
    ....
  }

你有文字解码。 您可以通过simmetric Writer / OutputStream方法使用您喜欢的编码（例如UTF-8）来编写它。

Answer 3

您需要知道输入文件的编码。 例如，如果文件是Latin-1，你会做这样的事情，

        FileInputStream fis = new FileInputStream("test.in");
        InputStreamReader isr = new InputStreamReader(fis, "ISO-8859-1");
        Reader in = new BufferedReader(isr);
        FileOutputStream fos = new FileOutputStream("test.out");
        OutputStreamWriter osw = new OutputStreamWriter(fos, "UTF-8");
        Writer out = new BufferedWriter(osw);

        int ch;
        while ((ch = in.read()) > -1) {
            out.write(ch);
        }

        out.close();
        in.close();

Answer 4

你只想把它读作UTF-8？ 我最近给出类似问题的是用-Dfile.encoding = UTF-8启动JVM，并正常读取/打印。 我不知道这是否适用于您的情况。

有了这个选项：

System.out.println("á é í ó ú")

正确打印字符。 否则打印出来？ 符号