通过BufferedInputStream bufferedOutputStream读写文件

代码：

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.ByteArrayOutputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

public class FileTools {
    public static byte[] readFile(String string) {
        FileInputStream fileInputStream=null;
        BufferedInputStream bufferedInputStream=null;
        ByteArrayOutputStream bao=new ByteArrayOutputStream();
        byte[] buff=new byte[1024];
        try {
            fileInputStream=new FileInputStream(string);
            bufferedInputStream=new BufferedInputStream(fileInputStream);
            int bytesRead=0;
            while (-1!=(bytesRead=bufferedInputStream.read(buff,0,buff.length))) {
                bao.write(buff,0,bytesRead);
            }
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally{
            try {
                fileInputStream.close();
                bufferedInputStream.close();
                buff=null;
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        return bao.toByteArray();
    }

    public static void writeFile(String string,byte[] bytes) {
        FileOutputStream fileOutputStream=null;
        BufferedOutputStream bufferedOutputStream=null;
        try{
            fileOutputStream=new FileOutputStream(string);
            bufferedOutputStream =new BufferedOutputStream(fileOutputStream);
            bufferedOutputStream.write(bytes);
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally{
            try {
                bufferedOutputStream.flush();
                fileOutputStream.close();
                bufferedOutputStream.close();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }
}