java sha_原生Java实现SHA256算法
package sha256demo;
import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
public class Sha256 {
/**
* 利用java原生的类实现SHA256加密
*
* @param str 加密后的报文
* @return
*/
public static String getSHA256(String str) {
MessageDigest messageDigest;
String encodestr = "";
try {
messageDigest = MessageDigest.getInstance("SHA-256");
messageDigest.update(str.getBytes("UTF-8"));
encodestr = byte2Hex(messageDigest.digest());
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
return encodestr;
}
/**
* 将byte转为16进制
*
* @param bytes
* @return
*/
private static String byte2Hex(byte[] bytes) {
StringBuffer stringBuffer = new StringBuffer();
String temp = null;
for (int i = 0; i < bytes.length; i++) {
temp = Integer.toHexString(bytes[i] & 0xFF);
if (temp.length() == 1) {
// 1得到一位的进行补0操作
stringBuffer.append("0");
}
stringBuffer.append(temp);
}
return stringBuffer.toString();
}
}