文件的输入(或是键盘输入)追加至文件中 笔记

1.文件的输入追加至文件中：
	使用buffer： 键盘输入 / 文件输入
	InputStreamReader ： 字节 -> 字符 ，
	如果不使用buffer,那InputStreamReader使用read 用的是 char[](原本的InputStream子类 使用的是 byte[])
	InputStreamReader ： 是字节流与字符流之间的桥梁，能将字节流输出为字符流，并且能为字节流指定字符集，可输出一个个的字符
	使用buffer,就加一层外装，拥有readline方法
	写入也是使用buffer来写入进去
	
	1.键盘输入
	使用buffer的转化成字符流：
		BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
		BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter(this.file,true));
		String eof = bufferedReader.readLine();
		while(! eof.equals("EOF")) {  
		//设置EOF行 作为结束的标志
			bufferedWriter.write(eof);
			bufferedWriter.newLine();
			eof = bufferedReader.readLine();
		}
		bufferedReader.close();
		bufferedWriter.close();
	
	源码：
					InputStreamReader
		 public int read(char cbuf[], int offset, int length) throws IOException {
	        return sd.read(cbuf, offset, length);
	    }
	    			BufferedReader
	    public String readLine() throws IOException {
	        return readLine(false);
	    }
	    			FileWriter
	    public FileWriter(File file, boolean append) throws IOException {
	        super(new FileOutputStream(file, append));
	    }			
	 
	 2.文件输入： 
	 	1.使用Buffer的转换成字符流：
	 		BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(new FileInputStream(this.file)));
			BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter(".\\newRWtext.txt",true));

			String eof = bufferedReader.readLine();
			while(eof != null) {
				bufferedWriter.write(eof);
				bufferedWriter.newLine();
				eof = bufferedReader.readLine();
			}
			bufferedReader.close();
			bufferedWriter.close();
    	
    	2.不使用buffer的字节流：
    		FileInputStream fileInputStream = new FileInputStream(this.file);
			FileOutputStream fileOutputStream = new FileOutputStream(new File(".\\neRWtext.txt"));
			byte[] data = new byte[1024];
			int bCount = 0;
			int bSize = 0;
			while ( (bCount = fileInputStream.read(data)) != -1 ) {
				fileOutputStream.write(data);
				bSize += bCount;
			}
			fileInputStream.close();
			fileOutputStream.close();
    


附加：流的自动关闭：（将流的创建放入try内）
	try (BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(new FileInputStream(this.file)));
			BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter(".\\neRWtext.txt",true))){ 
			if(!this.file.exists()){
				this.file.createNewFile();	
			}

			String eof = bufferedReader.readLine();
			while(eof != null) {
				bufferedWriter.write(eof);
				bufferedWriter.newLine();
				eof = bufferedReader.readLine();
			}
			System.out.println("已完成写入");
		} catch (Exception e) {
			e.printStackTrace();
		}