package LIU;import java.io.*;public class TestFile3 {    public static void main(String[] args) {        //字节写入读出                        try{            //写入            FileOutputStream fos=new FileOutputStream("d:\\test1.txt",true);                        //String str2="追加写入";            String str="\n大家下午好 ";            fos.write(str.getBytes());//覆盖写入                        //追加写入            //FileOutputStream(name,true)                                    fos.close();            //读出            FileInputStream fis=new FileInputStream("d:\\test1.txt");            byte[]b=new byte[200];            int i=fis.read(b);            String str1=new String(b,0,i);            System.out.println("读取内容："+str1);            fis.close();                    }catch(Exception e)        {            e.printStackTrace();        }

package LIU;import java.io.*;public class TsetFile4 {    public static void main(String[] args) {                try {            //读取            FileReader fr=new FileReader("d:\\test1.txt");            char[]c=new char[200];                        int i=fr.read(c);            String str=new String(c,0,i);            System.out.println("读取内容："+str);            fr.close();            //写入            FileWriter fw=new FileWriter("d:\\test1.txt",true);            fw.write("\n新写入的内容");            fw.close();                                } catch (Exception e) {            e.printStackTrace();        }    }