工具类总结

MD5加密工具类：

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public final class MD5 {
    

    public static String encrypt(String strSrc) {
    
        try {
    
            char hexChars[] = {
     '0', '1', '2', '3', '4', '5', '6', '7', '8',
                    '9', 'a', 'b', 'c', 'd', 'e', 'f' };
            byte[] bytes = strSrc.getBytes();
            MessageDigest md = MessageDigest.getInstance("MD5");
            md.update(bytes);
            bytes = md.digest();
            int j = bytes.length;
            char[] chars = new char[j * 2];
            int k = 0;
            for (int i = 0; i < bytes.length; i++) {
    
                byte b = bytes[i];
                chars[k++] = hexChars[b >>> 4 & 0xf];
                chars[k++] = hexChars[b & 0xf];
            }
            return new String(chars);
        } catch (NoSuchAlgorithmException e) {
    
            e.printStackTrace();
            throw new RuntimeException("MD5加密出错！！+" + e);
        }
    }

    public static void main(String[] args) {
    
        System.out.println(MD5.encrypt("111111"));
    }

}

ResponseUtil ：

写出 response 流

import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;

import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class ResponseUtil {
    

    public static void out(HttpServletResponse response, R r) {
    
        ObjectMapper mapper = new ObjectMapper();
        response.setStatus(HttpStatus.OK.value());
        response.setContentType(MediaType.APPLICATION_JSON_UTF8_VALUE);
        try {
    
            mapper.writeValue(response.getWriter(), r);
        } catch (IOException e) {
    
            e.printStackTrace();
        }
    }
}