javase练习（排序，IO流，机试,综合），javaseio

public class FileWrite {

	public static void main(String[] args) {
		BufferedWriter bw = null;
		BufferedReader br = null;
		BufferedReader br1 = null;

		int[] arr = new int[5];
		System.out.println("请输入5个整数：");
		try {
			br = new BufferedReader(new InputStreamReader(System.in));// 字符输入流 从键盘读取数据
			bw = new BufferedWriter(new FileWriter("D:/result.txt"));//字符输出流  写数据到文件
			br1 = new BufferedReader(new FileReader("D:/result.txt"));//字符输入流 从文件读取数据
																		
			for (int i = 0; i < arr.length; i++) {
				String str = br.readLine();
				arr[i] = Integer.valueOf(str);
				System.out.println(arr[i]);
			}
			// 降序排列，从大到小
			for (int i = 1; i < arr.length; i++) {
				for (int j = 0; j < arr.length - i; j++) {
					if (arr[j] < arr[j + 1]) {
						int temp = arr[j];
						arr[j] = arr[j + 1];
						arr[j + 1] = temp;
					}
				}
			}
			// 将排序好的数据，写入到目标文件中；
			for (int num : arr) {
				bw.write(String.valueOf(num) + " ");
			}
			bw.flush();
			System.out.println("读取文件内容：" + br1.readLine());
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			try {
				br1.close();
				bw.close();
				br.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}

	}
}

实验如下：