MessageDigest加密

MessageDigest 类为应用程序提供信息摘要算法的功能，如 MD5 或 SHA 算法。信息摘要是安全的单向哈希函数，它接收任意大小的数据，并输出固定长度的哈希值。

 

md = MessageDigest.getInstance("SHA-1");
md.update(text.getBytes());//text要转換字符串
md.digest()//返回hash串

 

algorithm类型:

MD2: The MD2 message digest algorithm as defined in RFC 1319.

 

MD5: The MD5 message digest algorithm as defined in RFC 1321.

SHA-1: The Secure Hash Algorithm, as defined in Secure Hash Standard, NIST FIPS 180-1.

SHA-256, SHA-384, and SHA-512: SHA-256 is a 256-bit hash function intended to provide 128 bits of security against collision attacks, while SHA-512 is a 512-bit hash function intended to provide 256 bits of security. A 384-bit hash may be obtained by truncating the SHA-512 output.