<dependency>
            <groupId>commons-codec</groupId>
            <artifactId>commons-codec</artifactId>
            <version>1.8</version>
        </dependency>

    SHA1加密，MD2加密，MD5加密

            String pastSign = "abc";
            String Str1= org.apache.commons.codec.digest.DigestUtils.sha1Hex(pastSign).toUpperCase();
            String Str2 = org.apache.commons.codec.digest.DigestUtils.md2Hex(pastSign).toUpperCase();
            String Str3 = org.apache.commons.codec.digest.DigestUtils.md5Hex(pastSign).toUpperCase();
 

BASE64

//加密

String str= "abc"; // abc為要加密的字串

byte[] b = Base64.encodeBase64(str.getBytes(), true);

System.out.println(new String(b));

//解密

String str = "YWJj"; // YWJj為要解密的字串

byte[] b = Base64.decodeBase64(str.getBytes());

System.out.println(new String(b));