一、檢視檔案的二進位制碼

    想檢視一個檔案的二進位制碼有很多工具可以用HEX的方式讀檔案，例如：Notepad++、UltraEdit、HexViewer等等。

Notepad++的HEX-Editor：

 

二、DIY瀏覽器

1.初步實現的瀏覽功能：

軟體採用命令互動模式，提示輸入的命令有6個：

• ‘q’ 退出程式
• ‘u’ 向上翻頁
• ‘d’ 向下翻頁
• ‘s’ 跳至首頁
• ‘e’ 跳至尾頁
• ‘g’ 跳至指定頁

2.瀏覽器介紹

（1）幫助資訊
在執行Java程式後就可以看見提示資訊，我們直接輸入想檢視的檔名。

三、原始碼

【scanfile.java】

import java.io.*;  //匯入IO流
import java.util.Scanner;  //匯入Scanner類

public class scanfile { 
	public static void
 
 readfile() throws IOException{ //構造讀檔案函式
		String BookName; //定義"書名"變數
		int commandchar = 0;  //定義"命令"變數
		int pos = 0;  //定義"位置指標"變數
		int page = 1; //定義"頁碼"變數
		System.out.println("Reading software  2018 ygaairspace Copyright(C)");
		System.out.println("Usage: input anyfilename");
		Scanner scan1 = new Scanner
 
(System.in); //控制檯輸入"書名"
		BookName = scan1.nextLine();
		File file = new File(BookName); //建立File物件file
		if(!(file.exists())){ //利用File類的exists方法判斷檔案是否存在
			System.out.println("\nfile " +file.getName()+ " not found\n");
		}
		
		RandomAccessFile raf = new RandomAccessFile(BookName,"r");//建立RandomAccessFile物件raf
		try{
			System.out.println("\nCol | 0      1      2      3      4      5      6      7");
			System.out.println("----|----------------------------------------------------");
			raf.seek(pos); //定位檔案指標所指位置
			for(int i=0;i<14;i++){
				for(int j=0;j<8;j++){
					//System.out.println(" "+i+" "+bufr.read());
					String str16 = Integer.toHexString(raf.read());
					System.out.print("     "+str16);
					pos++; //每次讀取14*8=112個字元
					if((j)%8 == 0){ //一行輸出8個碼字後換行
						System.out.print("\n");
					}
				}
			}
			page = pos/112; //頁碼計算
			//System.out.println("\n"+"dos2:"+dos);
		}catch(Exception e){
			e.printStackTrace();
		}
		System.out.println("\n\n                           <page"+page+">"); //輸出頁碼
		System.out.println("\n\ncommand key: q(uit)  u(p)  d(own)  s(tart)  e(nd)  g(o pages)");
		System.out.println("new command > ");

		while(true){
			try {
				commandchar = System.in.read();//將輸入的指令字元轉化為ACSII碼
			} catch (IOException e) {
				e.printStackTrace();
			}
			if(commandchar == 113){ //字元'q'，退出程式
				System.exit(0);
				commandchar = 0;//重置"命令"變數
			}
			if(commandchar == 100){//字元'd'，向下翻頁
				System.out.println("\nCol | 0      1      2      3      4      5      6      7");
				System.out.println("----|----------------------------------------------------");
				raf.seek(pos);
				for(int i=0;i<14;i++){
					for(int j=0;j<8;j++){
						String str16 = Integer.toHexString(raf.read());
						System.out.print("     "+str16);
						pos++;
						if((j)%8 == 0){
							System.out.print("\n");
						}
					}
				}
				page = pos/112;
				System.out.println("\n\n                           <page"+page+">");
				System.out.println("\nyour last command code is "+"'"+((char)commandchar)+"'");
				System.out.println("command key: q(uit)  u(p)  d(own)  s(tart)  e(nd)  g(o pages)");
				System.out.println("new command > ");
				commandchar = 0;
				//System.out.println("\n"+"dos3:"+dos);
			}
			if(commandchar == 117){//字元'u'，向上翻頁
				if(pos==112){ //判斷檔案指標是否在第1頁，如在第1頁，就再次輸出第一頁碼字
					raf.seek(0);
					System.out.println("\nCol"+page+"| 0       1       2       3       4       5       6       7");
					System.out.println("-----|-------------------------------------------------------------");
					for(int i=0;i<14;i++){
						for(int j=0;j<8;j++){
							String str16 = Integer.toHexString(raf.read());
							System.out.print("     "+str16);
							pos++;
							if((j)%8 == 0){
								System.out.print("\n");
							}
						}
					}
					page = pos/112;
					System.out.println("\n\n                           <page"+page+">");
					System.out.println("\nyour last command code is "+"'"+((char)commandchar)+"'");
					System.out.println("command key: q(uit)  u(p)  d(own)  s(tart)  e(nd)  g(o pages)");
					System.out.println("new command > ");
				}
				else{
					pos -= 224; //不在第1頁，就減去兩頁的字元，共224個，將指標定位在上一頁開頭
					System.out.println("\nCol | 0      1      2      3      4      5      6      7");
					System.out.println("----|----------------------------------------------------");
					//System.out.println("\n"+"dos4:"+dos);
					raf.seek(pos);
					for(int i=0;i<14;i++){
						for(int j=0;j<8;j++){
							String str16 = Integer.toHexString(raf.read());
							System.out.print("     "+str16);
							pos++;
							if((j)%8 == 0){
								System.out.print("\n");
							}
						}
					}
					page = pos/112;
					System.out.println("\n\n                           <page"+page+">");
					System.out.println("\nyour last command code is "+"'"+((char)commandchar)+"'");
					System.out.println("command key: q(uit)  u(p)  d(own)  s(tart)  e(nd)  g(o pages)");
					System.out.println("new command > ");
				}
				commandchar = 0;
			}
			if(commandchar == 115){ //字元's'，讀取第一頁
				pos = 0;//將位置指標定位在檔案開頭
				raf.seek(pos);
				System.out.println("\nCol | 0      1      2      3      4      5      6      7");
				System.out.println("----|----------------------------------------------------");
				for(int i=0;i<14;i++){
					for(int j=0;j<8;j++){
						String str16 = Integer.toHexString(raf.read());
						System.out.print("     "+str16);
						pos++;
						if((j)%8 == 0){
							System.out.print("\n");
						}
					}
				}
				page = pos/112;
				System.out.println("\n\n                           <page"+page+">");
				System.out.println("\nyour last command code is "+"'"+((char)commandchar)+"'");
				System.out.println("command key: q(uit)  u(p)  d(own)  s(tart)  e(nd)  g(o pages)");
				System.out.println("new command > ");
				commandchar = 0;
			}
			if(commandchar == 101){ //字元'e'，讀取最後一頁
				long end = raf.length()-1; //獲取檔案末尾位置
				pos = (int) (end - 112); //將位置指標移至最後一頁的開頭
				System.out.println("\nCol | 0      1      2      3      4      5      6      7");
				System.out.println("----|----------------------------------------------------");
				//System.out.println("\n"+"dos4:"+dos);
				raf.seek(pos);
				for(int i=0;i<14;i++){
					for(int j=0;j<8;j++){
						String str16 = Integer.toHexString(raf.read());
						System.out.print("     "+str16);
						pos++;
						if((j)%8 == 0){
							System.out.print("\n");
						}
					}
				}
				page = pos/112; 
				System.out.println("\n\n                           <page"+page+">");
				System.out.println("\nyour last command code is "+"'"+((char)commandchar)+"'");
				System.out.println("command key: q(uit)  u(p)  d(own)  s(tart)  e(nd)  g(o pages)");
				System.out.println("new command > ");
				commandchar = 0;
			}
			if(commandchar == 103){ //字元'g'，跳轉至指定頁
				System.out.println("\npage? Example：1 2 3... >");
				Scanner scan2 = new Scanner(System.in); //控制檯輸入"頁碼"
				int jump = scan2.nextInt(); //讀取輸入的頁碼
				pos = jump*112-112; //將位置指標定位在指定頁的開頭
				System.out.println("\nCol | 0      1      2      3      4      5      6      7");
				System.out.println("----|----------------------------------------------------");
				raf.seek(pos);
				for(int i=0;i<14;i++){
					for(int j=0;j<8;j++){
						String str16 = Integer.toHexString(raf.read());
						System.out.print("     "+str16);
						pos++;
						if((j)%8 == 0){
							System.out.print("\n");
						}
					}
				}
				page = pos/112;
				System.out.println("\n\n                           <page"+page+">");
				System.out.println("\nyour last command code is "+"'"+((char)commandchar)+"'");
				System.out.println("command key: q(uit)  u(p)  d(own)  s(tart)  e(nd)  g(o pages)");
				System.out.println("new command > ");
				commandchar = 0;
			}
		}
	}
		
	public static void main(String[] args) throws IOException {
		readfile(); //呼叫讀檔案函式
	}
}