[io流]-[机试题]-[读取-排序-输出]

将文件中的一行double数（空格隔开），排序后，输出（每个换行）

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;

public class IOTest {
	public static void main(String[] args) {
		//实例化输入输出文件
		File in = new File("D:\\in.txt");
		File out  = new File("D:\\out.txt");
		BufferedReader br = null;
		BufferedWriter bw = null;
		try {
			//实例化输入输出流
			br = new BufferedReader(new FileReader(in));
			bw = new BufferedWriter(new FileWriter(out));
			//读取该行数据
			String str = br.readLine();
			if(str!=null){
				//分割为String数组
				String[] param = str.split(" ");
				//定义double数组
				double[] paramDou = new double[param.length];
				//将String数组转换为double数组
				for(int i=0;i<param.length;i++){
					paramDou[i] = Double.parseDouble(param[i]);
				}
				//冒泡排序法，从小到大
				for(int i=0;i<paramDou.length;i++){
					for(int j=paramDou.length-1;j>i;j--){
						if (paramDou[j]<paramDou[i]){
							double x = paramDou[j];
							paramDou[j] = paramDou[i];
							paramDou[i] = x;
						}
					}
				}
				//将double数组转换为String数组
				for(int i=0;i<paramDou.length;i++){
					param[i] = Double.toString(paramDou[i]);
					System.out.println(param[i]);
                    //输出
					bw.write(param[i]);
					//换行
					bw.newLine();
				}
				
				bw.flush();
			}
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		}catch (IOException e) {
			e.printStackTrace();
		}finally{
			//释放资源
			try {
				if(br!=null){
					br.close();
				}
				if(bw!=null){
					bw.close();
				}
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
	}
}