JAVA读取文件

import java.io.*;public class asdas {public static void main(String[] args) throws IOException {/** * 一个指向路径的文件 */File datafile = new File("D:\\file.txt");/*String filename = "txtfile.txt"; String folder = "D:";  创建文件，提供文件路径和命名 File datafile = new File(folder,filename); */if(datafile.exists() && datafile.isFile()) {System.out.println("从中读取数据");} else {System.out.println("文件不存在");datafile.createNewFile();}System.out.println("文件中内容为：");//创建reader,指向文件FileReader filereader = new FileReader(datafile);//bufferedreader,用来读取指向文件BufferedReader br = new BufferedReader(filereader);String content = null;while((content = br.readLine()) != null) {System.out.println(content);}filereader.close();br.close();}}