JAVA IO - 將文件內容轉化爲十六進制顯示

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintStream;


public class ToHexTest {
	  public static void convertToHex(PrintStream out, File file) throws IOException {
	InputStream is = new FileInputStream(file);
	 
	int bytesCounter =0;		
	int value = 0;
	StringBuilder sbHex = new StringBuilder();
	StringBuilder sbText = new StringBuilder();
	StringBuilder sbResult = new StringBuilder();
 
	while ((value = is.read()) != -1) {    
	    //convert to hex value with "X" formatter
            sbHex.append(String.format("%02X ", value));
 
	    //If the chracater is not convertable, just print a dot symbol "." 
	    if (!Character.isISOControl(value)) {
	      	sbText.append((char)value);
	    }else {
	        sbText.append(".");
	    }
 
	    //if 16 bytes are read, reset the counter, 
            //clear the StringBuilder for formatting purpose only.
	    if(bytesCounter==15){
	      	sbResult.append(sbHex).append("      ").append(sbText).append("\n");
	       	sbHex.setLength(0);
	        sbText.setLength(0);
	       	bytesCounter=0;
	    }else{
	        bytesCounter++;
	    }
       }
 
	//if still got content
	if(bytesCounter!=0){			
	     //add spaces more formatting purpose only
	    for(; bytesCounter<16; bytesCounter++){
		//1 character 3 spaces
		sbHex.append("   ");
	    }
	    sbResult.append(sbHex).append("      ").append(sbText).append("\n");
        }
 
        out.print(sbResult);
        is.close();
  }
 
   public static void main(String[] args) throws IOException
   {	
    	//display output to console
    	convertToHex(System.out, new File("c:/work/hello/helloworld"));
 
    	//write the output into a file
    	convertToHex(new PrintStream("c:/work/hello/helloworld.hex"), new File("c:/work/hello/helloworld"));
    } 
}