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