java中文件读写常用方法

java中常用FileReader来读取文件，但是读出来是一个一个字符，我们可以用BufferedReader来一行一行读取

public class Test{

    public static void main(String[] args){
        try {
            FileReader r = new FileReader("a.txt");
            BufferedReader br=new BufferedReader(r);
            String str;
            while ((str =br.readLine())!= null){
                System.out.println(str);
            }
        }catch (Exception e){
            System.out.println(e.toString());
        }
    }
}

写入操作

import java.io.*;

public class FileGet {
    public static void main(String[] args) {
        try {
            BufferedWriter out = new BufferedWriter(new FileWriter("test.txt"));
            out.write("测试文字");
            out.append("dasd");
            out.newLine();
            out.write("你好");
            out.flush();
            out.close();
            System.out.println("文件创建成功！");
            BufferedReader in = new BufferedReader(new FileReader("test.txt"));
            StringBuffer sb;
            while (in.ready()) {
                sb = (new StringBuffer(in.readLine()));
                System.out.println(sb);
            }
            in.close();
        } catch (IOException e) {
        }
    }
}