JAVA文件读写操作详解

import java.io.BufferedInputStream;
import java.io.FileInputStream;

/**
 * BufferedInputStream:缓冲输入流
 * FileInputStream:文件输入流
 */
public class FileReadToString {
    public static void main(String[] args){
        try {
            FileInputStream fis=new FileInputStream("WynnNi.txt");
            BufferedInputStream bis=new BufferedInputStream(fis);
            String content=null;
             //自定义缓冲区
            byte[] buffer=new byte[10240];
            int flag=0;
            while((flag=bis.read(buffer))!=-1){
                content+=new String(buffer, 0, flag);
            }
            System.out.println(content);
            //关闭的时候只需要关闭最外层的流就行了
            bis.close();
        } catch (Exception e) {
                e.printStackTrace();
        }
    }
}

/**
 * BufferedOutputStream:缓冲输出流
 * FileOutPutStream:文件输出流
 */
public class StringOutPutToFile {
    public static void main(String[] args){
        try {
            FileOutputStream fos=new FileOutputStream("WynnNi.txt");
            BufferedOutputStream bos=new BufferedOutputStream(fos);
            String content="xxxxxxxxx！";
            bos.write(content.getBytes(),0,content.getBytes().length);
            bos.flush();
            bos.close();
        } catch (Exception e) {
                e.printStackTrace();
        }
    }
}