【每日日报】第三十六天

1 今天继续看书

综合实例

package File;
import java.io.*;

public class IOUtils {
    public static void print(byte[] ary){
        for(int b:ary){
            b &= 0xff;    //b=b&0xff
            if(b<=0xf) System.out.print("0");
            System.out.print(Integer.toHexString(b)+" ");
        }
        System.out.println();
    }
    public static byte[] read(String file){
        try{
            InputStream in=new FileInputStream(file);
             byte[] buf=new byte[in.available()];
             in.read(buf);
             in.close();
             return buf;
        }catch (IOException e){
            e.printStackTrace();
            throw new RuntimeException(e);
        }
    }
    public static Object deepCopy(Object obj){
        try{
            ByteArrayOutputStream buf=new ByteArrayOutputStream();
            ObjectOutputStream oos=new ObjectOutputStream(buf);
            oos.writeObject(obj);
            oos.close();
            byte[] ary=buf.toByteArray();
            ObjectInputStream ois=new ObjectInputStream(new ByteArrayInputStream(ary));
            Object o=ois.readObject();
            ois.close();
            return o;
        }catch(Exception e){
            throw new RuntimeException(e);
        }
    }
    public static void cp(File from,File to){
        try{
            InputStream in=new FileInputStream(from);
            OutputStream out=new FileOutputStream(to);
            byte[] buf=new byte[1024];
            int n;
            while((n=in.read(buf))!=-1){
                out.write(buf,0,n);
            }
            in.close();
            out.close();
        }catch (IOException e){
            e.printStackTrace();
            throw new RuntimeException(e);
        }
    }
    public static void cp1(File from,File to){
        try{
            InputStream in=new FileInputStream(from);
            OutputStream out=new FileOutputStream(to);
            int b;
            while((b=in.read())!=-1){
                out.write(b);
            }
            in.close();
            out.close();
        }catch(IOException e){
            e.printStackTrace();
            throw new RuntimeException(e);
        }
    }
    public static void cp(String from,String to){
        cp(new File(from),new File(to));
    }
    public static void print(File file){
        try{
            InputStream in=new FileInputStream(file);
            int b;
            int i=1;
            while((b=in.read())!=-1){
                if(b<=0xf) System.out.print("0");
            System.out.print(Integer.toHexString(b)+" ");
            if(i++%16==0) System.out.println();
        }
        System.out.println();
        in.close();
    }catch (IOException e){
        e.printStackTrace();
        throw new RuntimeException(e);
    }
}
    public static void print(String file){
        print(new File(file));
    }
    public static void split(String file,int size){
        try{
            if(size<=0){
                throw new IllegalArgumentException("搞啥呀！");
            }
            int idx=0;
            InputStream in=new BufferedInputStream(new FileInputStream(file));
            OutputStream out=new BufferedOutputStream(new FileOutputStream(file+"."+idx++));
            int b;
            int count=0;
            while((b=in.read())!=-1){
                out.write(b);
                count++;
                if(count%(size*1024)==0){
                    out.close();
                    out=new BufferedOutputStream(new FileOutputStream(file+"."+idx++));
                }
            }
            in.close();
            out.close();
        }catch(IOException e){
            e.printStackTrace();
            throw new RuntimeException(e);
        }
    }
    public static void join(String file){
        try{
            String filename=file.substring(0,file.lastIndexOf("."));
            String num=file.substring(file.lastIndexOf(".")+1);
            int idx=Integer.parseInt(num);
            OutputStream out=new FileOutputStream(filename);
            File f=new File(filename+"."+idx++);
            while(f.exists()){
                InputStream in=new FileInputStream(f);
                in.close();
                f=new File(filename+"."+idx++);
            }
            out.close();
        }catch(IOException e){
            e.printStackTrace();
            throw new RuntimeException(e);
        }
    }
    public static void cp(InputStream in,OutputStream out)throws IOException{
        byte[] buf=new byte[1024*512];
        int count;
        while((count=in.read(buf))!=-1){
            System.out.println(count);
            out.write(buf,0,count);
        }
        out.flush();    
    }
}

 上机练习

2 没遇到什么问题

3 明天开始在网上看java的教程