如何在 utf-8 中读写这个？

Question

我收到一个错误io.MalformedByteSequenceException: Invalid byte 2 of 2-byte UTF-8 sequence

解决办法是用UTF-8读写文件。

我的代码是：

InputStream input = null;
OutputStream output = null;
OutputStreamWriter bufferedWriter = new OutputStreamWriter( output, "UTF8");
input = new URL(url).openStream();
output = new FileOutputStream("DirectionResponse.xml");
byte[] buffer = new byte[1024];
for (int length = 0; (length = input.read(buffer)) > 0;) {
   output.write(buffer, 0, length);
}
BufferedReader br = new BufferedReader(new FileReader("DirectionResponse.xml" ));
FileWriter fstream = new FileWriter("ppre_DirectionResponse.xml");
BufferedWriter out = new BufferedWriter(fstream);

我正在读取一个 url 并将其写入文件 DirectionResponse.xml。然后读取 DirectionResponse.xml 并写入与 *ppre_DirecionResponse.xml* 相同的内容进行处理。

如何更改此设置，以便以 UTF-8 进行读写？

Answer 1

首先，您需要调用output.close()（或至少在重新打开文件进行输入之前调用output.flush()。这可能是您出现问题的主要原因。

那么，您不应该为此使用FileReader 或FileWriter，因为它始终使用平台默认编码（通常不是UTF-8）。来自the docs for FileReader：

这个类的构造函数假定默认的字符编码和默认的字节缓冲区大小是合适的。

您在使用FileWriter 时会遇到同样的问题。替换这个：

BufferedReader br = new BufferedReader(new FileReader("DirectionResponse.xml" ));

类似这样的：

BufferedReader br = new BufferedReader(new InputStreamReader(
    new FileInputStream("DirectionResponse.xml"), "UTF-8"));

fstream 也是如此。

Answer 2

Read and Write UTF-8 File in Java

我看到你正在用 utf-8 写作，但没有专门用 utf-8 阅读。按照我在链接中提供的示例进行操作。

try {
   Reader reader =
      new InputStreamReader(
         new FileInputStream(args[0]),"UTF-8");
   BufferedReader fin = new BufferedReader(reader);
   Writer writer =
      new OutputStreamWriter(
         new FileOutputStream(args[1]), "UTF-8");
   BufferedWriter fout = new BufferedWriter(writer);
   String s;
   while ((s=fin.readLine())!=null) {
      fout.write(s);
      fout.newLine();
   }

            //Remember to call close. 
            //calling close on a BufferedReader/BufferedWriter 
            // will automatically call close on its underlying stream 
   fin.close();
   fout.close();
} catch (IOException e) {
   e.printStackTrace();
}