新增方法:
输入:
BufferedReader breader=new BufferedReader(Reader reader);
.readLine()读取一行内容，返回字符串
输出:
BufferedWriter bwriter=new BufferedWirter(Writer writer);
.newLine() 写入一个换行符

输入:
File f =new File("C:\Users\10853\eclipse-workspace\hell\src\hell\abc");
BufferedReader reader=null;
try {

reader=new BufferedReader(new FileReader(f)); String line=null; while((line=reader.readLine())!=null)//要添上!=null，不像c语言赋值表达式整个也有个真假结果 { System.out.println(line); } }catch(FileNotFoundException e) { e.printStackTrace(); }catch(IOException e) { e.printStackTrace(); }finally { try { if(null!=reader) { reader.close(); } }catch(IOException e) { e.printStackTrace(); } }

输出:

File f=new File("D:d/c.txt"); BufferedWriter bwriter=null; try { bwriter=new BufferedWriter(new FileWriter(f)); String s="addad"; bwriter.write(s); bwriter.newLine(); bwriter.append("aaaff"); bwriter.flush(); }catch(FileNotFoundException e) { e.printStackTrace(); }catch(IOException e) { e.printStackTrace(); }finally { try { if(null!=bwriter) { bwriter.close(); } }catch(IOException e) { e.printStackTrace(); } }