import javax.imageio.IIOException;
import java.io.*;
import java.util.Date;

//字符输入流
public class FileManagerChar {
    public static void readCharFile(File file){
        FileReader fileReader=null;//文本输入流
        if(file.exists()){
            try {
                fileReader = new FileReader( file );//基于目标存在的文本文档输出流
                char[] chs=new char[50];//字符零时缓冲区
                int count=0;//存储实际读取的字符数量
                while((count=fileReader.read(chs,0,chs.length))!=-1){
                    String s=new String( chs,0,count );
                    System.out.println( s );
                }
            }catch (IOException e){
                e.printStackTrace();
            }finally {
                try {
                    fileReader.close();
                }catch(IOException e){
                    e.printStackTrace();
                }
            }
        }
    }
    //使用文本缓冲流读取文件
    public static void useBufferReader(File file){
        FileReader read=null;//基于文件的普通输入流
        BufferedReader br=null;//基于某个reader建立的字符缓冲流
        if(file.exists()){
            try {
                read=new FileReader( file );//基于文件建立普通文本输入流
                br=new BufferedReader( read );//基于某个read建立文本缓冲流
                char[] chs=new char[25];
                int count=0;
                while ((count=br.read(chs,0,chs.length))!=-1){
                    String s=new String( chs,0,count );
                    System.out.println( s );
                }
            }catch (IOException e){
                e.printStackTrace();
            }finally {
                try {
                    br.close();
                    read.close();
                    System.out.println( "关闭成功" );
                }catch (IOException e){
                    e.printStackTrace();
                }
            }

        }
    }
    //字节输出流
    public static void binaryOutStream(String filePath){
        String str="start=E:\\BaiduNetdiskDownload\\baidu6\\1.mp4";
        byte[] bys=str.getBytes();//将字符串转换为字节数组
        OutputStream out=null;
        try {
             out = new FileOutputStream( filePath);
             out.write(bys);
        }catch (IOException e){
            e.printStackTrace();
        }finally {
            try {
                out.close();
                System.out.println( "资源关闭" );
            }catch (IOException e){
                e.printStackTrace();
            }
        }
    }
    //使用字节缓冲输出流
    public static void useBufferedOutput(File file){
        OutputStream out=null;
        BufferedOutputStream bs=null;
        String str="日照香炉生紫烟,\n遥看瀑布挂前川。\n飞流直下三千尺,\n以适应河洛就停";
        byte[] bys=str.getBytes();
    if(file.exists()){
            try {
                System.out.println( file.getAbsolutePath() );
                out = new FileOutputStream( file.getAbsoluteFile()+"/李白诗.doc" );
                bs=new BufferedOutputStream( out );//基于某个outputstream建立缓冲输出流
                bs.write( bys ,0,bys.length);//写入目标文件
            }catch (IOException e){
                e.printStackTrace();
            }finally {
                try {
                    bs.close();
                    out.close();
                }catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }
    //字符输出流bufferwrite
    //file文件存储的目录
    //filename 文件名称
    //content 文件内容
    public static void useBufferedWriter(File fir,String fileName,String content){
        File file=null;
        Writer writer=null;
        BufferedWriter bw=null;
        if(fir.exists()){
            file=new File(fir,fileName );
            char chs[]=content.toCharArray();
            try {
                writer=new FileWriter( file );
                bw=new BufferedWriter( writer );//基于Writer实例创建字符缓冲流
                bw.write(chs);//将char型数组所有内容写入到目标文件中
            }catch (IOException e){
                e.printStackTrace();
            }finally {
                try {
                    bw.close();
                    writer.close();
                }catch (Exception e){
                    e.printStackTrace();
                }
            }

        }else{
            //创建目录后写入内容
            System.out.println( "目标文件目录没找到" );
        }
    }
    public static void copyFile(File target,File dir){
        InputStream in=null;
        OutputStream out=null;
        File copyFile=null;//目标写的文件对象
        if(target.exists()){//判断目标文件是否存在
            if(!dir.exists()){
                dir.mkdirs();//如果目标文件不存在，创建目录
            }
            try {
                in = new FileInputStream( target );//基于文件建立输入流
                String fileName=target.getName();//获取文件源名称
                //避免文件重名
                copyFile=new File(dir+"/"+new Date().getTime()+fileName);//基于目标写入文件对象
                out=new FileOutputStream( copyFile );//基于目标文件建立输出流
                byte[] bys=new byte[1024];//临时存储字节数据的缓冲区
                int count=0;//记录读取内容的临时变量
                while ((count=in.read(bys,0,bys.length))!=-1){
                    System.out.println( "文件赋值读写中，请稍后----" );
                    out.write( bys,0,count );//将临时缓冲区内容写入到目标文件中
                }
                System.out.println( "目标赋值完成" );
            }catch (IOException e){
                e.printStackTrace();
            }finally {
                try {
                    out.close();
                    in.close();
                }catch (IOException e){
                    e.printStackTrace();
                }
            }
        }
    }
    //emp序列化对象
    //target//序列化对象的目标文件
    //java序列化,将员工对象保存到文件中
    public static void javaSer(Employeee emp,File target){
        OutputStream out=null;
        ObjectOutputStream oos=null;//序列化输出流
        if(emp!=null){
            try {
                out = new FileOutputStream( target );
                oos = new ObjectOutputStream( out );
                oos.writeObject( emp );//将序列化对象保存到文件中
            }catch (IOException e){
                e.printStackTrace();
            }finally {
                try {
                    oos.close();
                    out.close();
                }catch (Exception e){
                    e.printStackTrace();
                }
            }
        }
    }
    //反序列化
    public static Employeee deser(File target) {
        InputStream in = null;
        ObjectInputStream ois = null;
        Employeee emp = null;
        if (target.exists()) {
            try {
                in = new FileInputStream( target );
                ois = new ObjectInputStream( in );
                //进行反序列化
                Object obj = ois.readObject();
                emp = obj != null ? (Employeee) obj : null;//如果不为空进行类型转换
            } catch (IOException e) {
                e.printStackTrace();
            } catch (ClassNotFoundException e) {
                e.printStackTrace();
            }finally {
                try {
                    ois.close();
                    in.close();
                }catch (IOException e){
                    e.printStackTrace();
                }
            }
        }
        return emp;//返回对象
    }
}

测试类

import java.io.File;

public class test95 {
    public static void main(String[] args){
        File file=new File( "e:/3.txt" );
        FileManagerChar.useBufferReader( file );
    }
}

运行结果