java：如何將文件轉換爲utf8

Question

我有一個非UTF8字符（如「ISO-8859-1」）的文件，所以我想將該文件（或讀取）轉換爲UTF8編碼，我怎麼能做到這一點？

是這樣的代碼：

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

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

... 

編輯：把編碼例如

Answer 1

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) { 
    .... 
    } 

有你有文本解碼。你可以用相似的Writer/OutputStream方法編寫你喜歡的編碼（例如UTF-8）。

Answer 2

你只想讀它作爲UTF-8？ 最近我做了一個類似的問題，就是使用-Dfile.encoding = UTF-8啓動JVM，並按正常方式讀/打印。我不知道這是否適用於你的情況。

與該選項：

System.out.println("á é í ó ú") 

打印正確的字符。否則，它打印一個？符號

Answer 3

您需要知道輸入文件的編碼。例如，如果該文件是拉美-1，你會做這樣的事情，

 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

下面的代碼轉換，從srcEncoding到tgtEncoding文件：

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(); 
     } 
    } 
} 

- 編輯 -

使用try-與資源（Java 7中）：

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); 
    } 
}