使用FileReader采用的默認編碼

package day170903; 
import java.io.*; 
public class TestDecoder {
	public static void main(String[] args) {
		FileReader fr = null;
		try {
			fr = new FileReader("G:/io/hello.txt");
			int len = 0;
			while((len=fr.read())!=-1) {
				System.out.println((char)len);
			}
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			try {
				if(fr!=null) {
					fr.close();
				}
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
	}
}

/**
 * Convenience class for reading character files.  The constructors of this
 * class assume that the default character encoding and the default byte-buffer
 * size are appropriate.  To specify these values yourself, construct an
 * InputStreamReader on a FileInputStream.
 *
 *這是一個很方便的讀取字符文件（文本文件）的類。
 *這個類的構造方法假設默認的字符編碼和默認的緩存數組大小是合適的（滿足需要的）。
 *假如你想自己指定字符編碼和緩存數組的大小，
 *請使用基於FileInputStream的InputStreamReader類。
 * <p><code>FileReader</code> is meant for reading streams of characters.
 * For reading streams of raw bytes, consider using a
 * <code>FileInputStream</code>.
 *
 *FileReader是設計為用來讀取字符流的。
 *想要讀取原始的字節流的話，可以考慮使用FileInputStream
 * @see InputStreamReader
 * @see FileInputStream
 *
 * @author      Mark Reinhold
 * @since       JDK1.1
 */

    public FileReader(String fileName) throws FileNotFoundException {
        super(new FileInputStream(fileName));
    }

    public InputStreamReader(InputStream in) {
        super(in);
        try {
            sd = StreamDecoder.forInputStreamReader(in, this, (String)null); // ## check lock object
        } catch (UnsupportedEncodingException e) {
            // The default encoding should always be available
            throw new Error(e);
        }
    }

    protected Reader(Object lock) {
        if (lock == null) {
            throw new NullPointerException();
        }
        this.lock = lock;
    }

sd = StreamDecoder.forInputStreamReader(in, this, (String)null);

public static StreamDecoder forInputStreamReader(InputStream in,
                                                 Object lock,
                                                 String charsetName)
    throws UnsupportedEncodingException
{
    String csn = charsetName;
    if (csn == null)
        csn = Charset.defaultCharset().name();
    try {
        if (Charset.isSupported(csn))
            return new StreamDecoder(in, lock, Charset.forName(csn));
    } catch (IllegalCharsetNameException x) { }
    throw new UnsupportedEncodingException (csn);
}

public static Charset defaultCharset() {
    if (defaultCharset == null) {
        synchronized (Charset.class) {
            String csn = AccessController.doPrivileged(
                new GetPropertyAction("file.encoding"));
            Charset cs = lookup(csn);
            if (cs != null)
                defaultCharset = cs;
            else
                defaultCharset = forName("UTF-8");
        }
    }
    return defaultCharset;
}

package day170903; 
import java.io.*; 
public class TestDefaultCharEncoding {
	public static void main(String[] args) {
		InputStreamReader isr = null;
		OutputStreamWriter osw = null;
		try {
			osw = new OutputStreamWriter(new FileOutputStream("G:/io/ISO-8859-1.txt"),"ISO-8859-1");
			isr = new InputStreamReader(new FileInputStream("G:/io/ISO-8859-1.txt"));
			char[] chars = "Est-ce possible que tu sois en train de penser à moi lorsque tu me manques?".toCharArray();
			osw.write(chars);
			osw.flush();
			int len = 0;
			while((len=isr.read())!=-1) {
				System.out.print((char)len);
			}
		} catch (UnsupportedEncodingException | FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			try {
				if(isr!=null) {
					isr.close();
				}
				if(osw!=null) {
					osw.close();
				}
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
	}
}

public static List<String> getLines( String fileName )  
{  
    List<String> lines = new ArrayList<String>();  
    try  
    {  
        BufferedReader br = new BufferedReader(new FileReader(fileName));  
        String line = null;  
        while( ( line = br.readLine() ) != null )  
            lines.add(new String(line.getBytes("GBK"), "UTF-8"));  
        br.close();  
    }  
    catch( FileNotFoundException e )  
    {  
    }  
    catch( IOException e )  
    {  
    }  
    return lines;  
}  

public static List<String> getLines( String fileName )  
{  
    List<String> lines = new ArrayList<String>();  
    try  
    {  
        BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream(fileName), "UTF-8"));  
        String line = null;  
        while( ( line = br.readLine() ) != null )  
            lines.add(line);  
        br.close();  
    }  
    catch( FileNotFoundException e )  
    {  
    }  
    catch( IOException e )  
    {  
    }  
    return lines;  
}