Methods to encrypt and decrypt Strings and files (file encryption and decryption doesn't work for photos). Requires Apache Commons Lang.

Encryptor.java

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Arrays;
import java.util.Scanner;

import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

import org.apache.commons.codec.binary.Base64;

public class Encryptor {
	
	public static void main(String[] args) throws Exception {
      String original = "Hello World!";
    	System.out.println("Original: " + original);
      String encrypted = encrypt("abc123ghidef9123", "RandomInitVector", original);
      System.out.println("Encrypted: " + encrypted);
      System.out.println("Decrypted: " + decrypt("abc123ghidef9123", "RandomInitVector", encrypted));
  }
	
	public static void encryptFile(File f, String key, String iv) throws IOException {
		BufferedReader br = new BufferedReader(new FileReader(f));
		int i = 0;
		String line = null;
		while ((line = br.readLine()) != null) {
		   i++;
		}
		String[] linesToEncrypt = new String[i];
		BufferedReader br1 = new BufferedReader(new FileReader(f));
		int i1 = 0;
		String line1 = null;
		while ((line1 = br1.readLine()) != null) {
		   linesToEncrypt[i1] = line1;
		   System.out.println("Processing line " + i1 + ": " + line1);
		   i1++;
		}
		String[] encryptedLines = new String[i];
		Arrays.fill(encryptedLines, "");
		int i2 = 0;
		for(String line2 : linesToEncrypt) {
			System.out.println(line2);
			encryptedLines[i2] = encrypt(key, iv, line2);
			i2++;
		}
    	f.delete();
    	f.createNewFile();
    	for(String line3 : encryptedLines) {
    		BufferedWriter bw = null;
    		FileWriter fw = null;
    		try {
    			String data = line3 + "\n";
    			fw = new FileWriter(f.getAbsoluteFile(), true);
    			bw = new BufferedWriter(fw);
    			bw.write(data);
    		} catch (IOException e) {
    			e.printStackTrace();
    		} finally {
    			try {
    				if (bw != null)
    					bw.close();
    				if (fw != null)
    					fw.close();
    			} catch (IOException ex) {
    				ex.printStackTrace();
    			}
    		}
    	}
    }
	
	public static void decryptFile(File f, String key, String iv) throws IOException {
		BufferedReader br = new BufferedReader(new FileReader(f));
		int i = 0;
		String line = null;
		while ((line = br.readLine()) != null) {
		   i++;
		}
		String[] linesToDecrypt = new String[i];
		BufferedReader br1 = new BufferedReader(new FileReader(f));
		int i1 = 0;
		String line1 = null;
		while ((line1 = br1.readLine()) != null) {
		   linesToDecrypt[i1] = line1;
		   System.out.println("Processing line " + i1 + ": " + line1);
		   i1++;
		}
		String[] decryptedLines = new String[i];
		Arrays.fill(decryptedLines, "");
		int i2 = 0;
		for(String line2 : linesToDecrypt) {
			System.out.println(line2);
			decryptedLines[i2] = decrypt(key, iv, line2);
			i2++;
		}
    	f.delete();
    	f.createNewFile();
    	for(String line3 : decryptedLines) {
    		BufferedWriter bw = null;
    		FileWriter fw = null;
    		try {
    			String data = line3 + "\n";
    			fw = new FileWriter(f.getAbsoluteFile(), true);
    			bw = new BufferedWriter(fw);
    			bw.write(data);
    		} catch (IOException e) {
    			e.printStackTrace();
    		} finally {
    			try {
    				if (bw != null)
    					bw.close();
    				if (fw != null)
    					fw.close();
    			} catch (IOException ex) {
    				ex.printStackTrace();
    			}
    		}
    	}
    }

	public static String encrypt(String key, String initVector, String value) {
        try {
            IvParameterSpec iv = new IvParameterSpec(initVector.getBytes("UTF-8"));
            SecretKeySpec skeySpec = new SecretKeySpec(key.getBytes("UTF-8"), "AES");

            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING");
            cipher.init(Cipher.ENCRYPT_MODE, skeySpec, iv);

            byte[] encrypted = cipher.doFinal(value.getBytes());

            return Base64.encodeBase64String(encrypted);
        } catch (Exception ex) {
            ex.printStackTrace();
        }

        return null;
    }

    public static String decrypt(String key, String initVector, String encrypted) {
        try {
            IvParameterSpec iv = new IvParameterSpec(initVector.getBytes("UTF-8"));
            SecretKeySpec skeySpec = new SecretKeySpec(key.getBytes("UTF-8"), "AES");

            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING");
            cipher.init(Cipher.DECRYPT_MODE, skeySpec, iv);

            byte[] original = cipher.doFinal(Base64.decodeBase64(encrypted));

            return new String(original);
        } catch (Exception ex) {
            ex.printStackTrace();
        }

        return null;
    }
    
}