import java.io.BufferedReader; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileReader; import java.io.IOException; import java.io.InputStream; import java.io.Reader; public class IORead {  /**   * @param args   * 文件的读写   */  public static void main(String[] args) {   // TODO Auto-generated method stub   try {    // 方法一    BufferedReader br = new BufferedReader(new FileReader(new File(    "D:/project/transfar/doc/1.txt")));    // StringBuilder bd = new StringBuilder();    StringBuffer bd = new StringBuffer();    while (true) {     String str = br.readLine();     if (str == null) {      break;     }     System.out.println(str);     bd.append(str);    }    br.close();    // System.out.println(bd.toString());    // 方法二    InputStream is = new FileInputStream(new File("D:/project/transfar/doc/1.txt"));    byte b[] = new byte[Integer.parseInt(new File("D:/project/transfar/doc/1.txt").length()    + "")];    is.read(b);    System.out.write(b);    System.out.println();    is.close();    // 方法三    Reader r = new FileReader(new File("D:/project/transfar/doc/1.txt"));    char c[] = new char[(int) new File("D:/project/transfar/doc/1.txt").length()];    r.read(c);    String str = new String(c);    System.out.print(str);    r.close();   } catch (RuntimeException e) {    // TODO Auto-generated catch block    e.printStackTrace();   } catch (FileNotFoundException e) {    // TODO Auto-generated catch block    e.printStackTrace();   } catch (IOException e) {    // TODO Auto-generated catch block    e.printStackTrace();   }  } }