從文件中讀取數據到集合

 IO流分類：
    流向
                   輸入流    讀取數據    FileReader    Reader
                   輸出流    寫出數據    FileWriter     Writer
    數據類型
            *字節流    
                   字節輸入流   讀取數據    InputStream
                   字節輸出流   寫出數據    OutputStream
            *字符流
                  字符輸入流  讀取數據    Reader
                  字符輸出流  寫出數據    Writer

/從文件中讀數據到集合
	public static void readData(String fileName,ArrayList<Student> array) throws IOException {
		//創建輸入緩衝流對象
		BufferedReader br = new BufferedReader(new FileReader(fileName));
		
		String line;
		while((line=br.readLine())!=null) {
			String[] datas = line.split(",");
			Student s = new Student();
			s.setId(datas[0]);
			s.setName(datas[1]);
			s.setAge(datas[2]);
			s.setAddress(datas[3]);
			array.add(s);
		}
		
		br.close();
	}
	

	//把集合中的數據寫入文件
	public static void writeData(String fileName,ArrayList<Student> array) throws IOException {
		//創建輸出緩衝流對象
		BufferedWriter bw = new BufferedWriter(new FileWriter(fileName));
		
		for(int x=0; x<array.size(); x++) {
			Student s = array.get(x);
			StringBuilder sb = new StringBuilder();
			sb.append(s.getId()).append(",").append(s.getName()).append(",").append(s.getAge()).append(",").append(s.getAddress());
			
			bw.write(sb.toString());
			bw.newLine();
			bw.flush();
		}
		
		bw.close();
	}