2.3.6文件的加密/解密

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import java.io.*;

public class MyEncryp {
    public static void main(String[] args){
        try {
            File inFile = new File("D:/work/test.txt");
            File outFile = new File("D:/test1.txt");
            
            FileInputStream fis = new FileInputStream(inFile);
            FileOutputStream fos = new FileOutputStream(outFile);
            
            int length = fis.available();
            for (int i = 0; i < length; i++) {
                fos.write(fis.read()+100);
            }
        } catch (Exception e) {
            // TODO: handle exception
        }
    }
}

test.txt
abcdefghijklmnopqrstuvwxyz

test1.txt
牌侨墒颂臀闲岩釉罩棕仝圮蒉

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import java.io.*;

public class MyDecrypt {
    public static void main(String[] args){
        try {
            File f = new File("D:/test1.txt");
            
            
            FileInputStream fis = new FileInputStream(f);
            
            int length = fis.available();
            for (int i = 0; i < length; i++) {
                System.out.print((char)(fis.read()-100));
            }
        } catch (Exception e) {
            // TODO: handle exception
        }
    }
}

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import java.io.*;

public class MyEncryp {
    public static void main(String[] args){
        try {
            File inFile = new File("D:/work/test.txt");
            File outFile = new File("D:/test1.txt");
            
            FileInputStream fis = new FileInputStream(inFile);
            FileOutputStream fos = new FileOutputStream(outFile);
            
            int length = fis.available();
            for (int i = 0; i < length; i++) {
                fos.write(fis.read()+i%100);
            }
        } catch (Exception e) {
            // TODO: handle exception
        }
    }
}

运行结果：

acegikmoqsuwy{}�亙厙墜崗憮

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/**
 * 生成密钥文件
 * @author lx
 *
 */
import java.io.*;

public class MyKey {
    public static void main(String[] args){
        try {
            File file = new File("D:/key.key");
            
            FileOutputStream fos = new FileOutputStream(file);
            
            for (int i = 0; i < 128; i++) {
                fos.write((int)(Math.random()*128));
            }
        } catch (Exception e) {
            // TODO: handle exception
        }
    }
}

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/**
 * 加密
 */
import java.io.*;

public class MyEncryp {
    public static void main(String[] args){
        try {
            //读密钥文件
            int key[] = new int[128];
            File keyFile = new File("D:/key.key");
                    
            FileInputStream keyFis = new FileInputStream(keyFile);
            
            for (int i = 0; i < 128; i++) {
                key[i] = keyFis.read();
            }
            
            //加密
            File inFile = new File("D:/work/test.txt");
            File outFile = new File("D:/test1.txt");
            
            FileInputStream fis = new FileInputStream(inFile);
            FileOutputStream fos =new FileOutputStream(outFile);
            
            int length = fis.available();
            for (int i = 0; i < length; i++) {
                fos.write(fis.read()+key[i%128]);
            }
        } catch (Exception e) {
            // TODO: handle exception
        }
    }
}

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/**
 * 解密
 */
import java.io.*;

public class MyDecrypt {
    public static void main(String[] args){
        try {
            //读密钥文件
            int key[] = new int[128];
            File keyFile = new File("D:/key.key");
            
            FileInputStream keyFis = new FileInputStream(keyFile);
            
            for (int i = 0; i < 128; i++) {
                key[i] = keyFis.read();
            }
            
            //解密
            File f = new File("D:/test1.txt");
            
            
            FileInputStream fis = new FileInputStream(f);
            
            int length = fis.available();
            for (int i = 0; i < length; i++) {
                System.out.print((char)(fis.read()-key[i%128]));
            }
        } catch (Exception e) {
            // TODO: handle exception
        }
    }
}