直接上代码，是在springboot下直接test的

import org.apache.commons.codec.binary.Base64;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import java.security.SecureRandom;
import java.text.SimpleDateFormat;
import java.util.Date;

@RunWith(SpringRunner.class)
@SpringBootTest
public class RestapiApplicationTests {

    // 加密
    public static String Encrypt(String sSrc, String sKey) throws Exception {
        if (sKey == null) {
            System.out.print("Key为空null");
            return null;
        }
        // 判断Key是否为16位
        if (sKey.length() != 16) {
            System.out.print("Key长度不是16位");
            return null;
        }
        KeyGenerator kgen = KeyGenerator.getInstance("AES");
        kgen.init(128, new SecureRandom(sKey.getBytes()));
        SecretKey secretKey = kgen.generateKey();
        byte[] enCodeFormat = secretKey.getEncoded();
        SecretKeySpec skeySpec = new SecretKeySpec(enCodeFormat , "AES");

        Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");//"算法/模式/补码方式"
        cipher.init(Cipher.ENCRYPT_MODE, skeySpec);
        byte[] encrypted = cipher.doFinal(sSrc.getBytes("utf-8"));

        return new Base64().encodeToString(encrypted);//此处使用BASE64做转码功能，同时能起到2次加密的作用。
    }

    // 解密
    public static String Decrypt(String sSrc, String sKey) throws Exception {
        try {
            // 判断Key是否正确
            if (sKey == null) {
                System.out.print("Key为空null");
                return null;
            }
            // 判断Key是否为16位
            if (sKey.length() != 16) {
                System.out.print("Key长度不是16位");
                return null;
            }
            KeyGenerator kgen = KeyGenerator.getInstance("AES");
            kgen.init(128, new SecureRandom(sKey.getBytes()));
            SecretKey secretKey = kgen.generateKey();
            byte[] enCodeFormat = secretKey.getEncoded();
            SecretKeySpec skeySpec = new SecretKeySpec(enCodeFormat , "AES");

            Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
            cipher.init(Cipher.DECRYPT_MODE, skeySpec);
            byte[] encrypted1 = new Base64().decode(sSrc);//先用base64解密
            try {
                byte[] original = cipher.doFinal(encrypted1);
                String originalString = new String(original,"utf-8");
                return originalString;
            } catch (Exception e) {
                System.out.println(e.toString());
                return null;
            }
        } catch (Exception ex) {
            System.out.println(ex.toString());
            return null;
        }
    }

    @Test
    public void test() throws Exception {
        /*
         * 此处使用AES-128-ECB加密模式，key需要为16位。
         */
        String cKey = "1234567890123456";
        // 需要加密的字串
        String cSrc = "hello";
        System.out.println(cSrc);
        // 加密
        String enString = RestapiApplicationTests.Encrypt(cSrc, cKey);
        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyyMMdd HH:mm:ss");
        System.out.println("时间：" + simpleDateFormat.format(new Date()) + "加密后的字串是：" + enString);
        // 解密
        String DeString = RestapiApplicationTests.Decrypt(enString, cKey);
        System.out.println("时间：" + simpleDateFormat.format(new Date()) + "解密后的字串是：" + DeString);
    }
}

其他模式大同小异，动动脑子，就差不多了

效果