test.java

DES RSA MD5 实现身份认证

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileReader;
import java.io.FileWriter;
import java.math.BigInteger;
import java.util.Random;


public class test {

	public static void main(String arg[]) throws Exception {
		
		File file = new File("test.txt");
		FileInputStream in = new FileInputStream(file);
		ByteArrayOutputStream bout = new ByteArrayOutputStream();
		byte[] tmpbuf = new byte[1024];
		int count = 0;
		while ((count = in.read(tmpbuf)) != -1) {
			bout.write(tmpbuf, 0, count);
			tmpbuf = new byte[1024];
		}
		in.close();		
		//System.out.println(bout.toString());
		
		BufferedReader inre=new BufferedReader(new FileReader("test.txt"));
		String s1,s2=new String();
		while((s1=inre.readLine())!=null)
			s2+=s1;
	
		
		//File output=new File("out.txt");
		/*BufferedWriter output=new BufferedWriter(new FileWriter("out.txt"));
		output.write(s2, 0, s2.length());
		output.close();

		BufferedReader inr2=new BufferedReader(new FileReader("out.txt"));
		while((s1=inr2.readLine())!=null)
			s2+=s1;
			System.out.println(s2);*/
		
		Random x=new Random();
		BigInteger p=new BigInteger(1024,100,x);
		System.out.println(p.toString());
		
		BufferedWriter output=new BufferedWriter(new FileWriter("out.txt"));
		output.write(p.toString(),0, p.toString().length());
		output.close();
		
		BufferedReader inr2=new BufferedReader(new FileReader("out.txt"));
		while((s1=inr2.readLine())!=null)
			s2+=s1;
			System.out.println(s2);
			
		BigInteger q=new BigInteger(s2);
		System.out.println(q.toString());

	}
}