FileReader默认编码

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.
 *
 *这是一个很方便的读取字符文件（文本文件）的类。
 *这个类的构造方法假设默认的字符编码和默认的缓存数组大小是合适的（满足需要的）。
 *假如你想自己指定字符编码和缓存数组的大小，
 *请使用基于FileInputStream的InputStreamReader类。
 * <p><code>FileReader</code> is meant for reading streams of characters.
 * For reading streams of raw bytes, consider using a
 * <code>FileInputStream</code>.
 *
 *FileReader是设计为用来读取字符流的。
 *想要读取原始的字节流的话，可以考虑使用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;  
}