springboot常用注解和工具类

1、requestParam

https://blog.csdn.net/sswqzx/article/details/84195043?ops_request_misc=%257B%2522request%255Fid%2522%253A%2522163419700416780255256244%2522%252C%2522scm%2522%253A%252220140713.130102334…%2522%257D&request_id=163419700416780255256244&biz_id=0&utm_medium=distribute.pc_search_result.none-task-blog-2_alltop_positive~default-1-84195043.first_rank_v2_pc_rank_v29&utm_term=%40RequestParam&spm=1018.2226.3001.4187

前端搭配（vue）：



后端拿值（url）

2、param

2.5 @PathVariable

3、Md5加密

CommonUtils.MD5（xxxx）

package net.xdclass.online_xdclass.utils;

import java.security.MessageDigest;

/**
 * 工具类
 */
public class CommonUtils {
    
    


    /**
     * MD5加密工具类
     * @param data
     * @return
     */
    public static String MD5(String data)  {
    
    
        try {
    
    
            java.security.MessageDigest md = MessageDigest.getInstance("MD5");
            byte[] array = md.digest(data.getBytes("UTF-8"));
            StringBuilder sb = new StringBuilder();
            for (byte item : array) {
    
    
                sb.append(Integer.toHexString((item & 0xFF) | 0x100).substring(1, 3));
            }

            return sb.toString().toUpperCase();
        } catch (Exception exception) {
    
    
        }
        return null;

    }

}

4、jwt

package net.xdclass.online_xdclass.utils;

import io.jsonwebtoken.Claims;
import io.jsonwebtoken.Jwts;
import io.jsonwebtoken.SignatureAlgorithm;
import net.xdclass.online_xdclass.model.entity.User;

import java.util.Date;

/**
 * Jwt工具类
 * 注意点:
 * 1、生成的token, 是可以通过base64进行解密出明文信息
 * 2、base64进行解密出明文信息，修改再进行编码，则会解密失败
 * 3、无法作废已颁布的token，除非改秘钥
 */
public class JWTUtils {
    
    


    /**
     * 过期时间，一周
     */
    private  static final long EXPIRE = 60000 * 60 * 24 * 7;
    //private  static final long EXPIRE = 1;


    /**
     * 加密秘钥
     */
    private  static final String SECRET = "xdclass.net168";


    /**
     * 令牌前缀
     */
    private  static final String TOKEN_PREFIX = "xdclass";


    /**
     * subject
     */
    private  static final String SUBJECT = "xdclass";


    /**
     * 根据用户信息，生成令牌
     * @param user
     * @return
     */
    public static String geneJsonWebToken(User user){
    
    

        String token = Jwts.builder().setSubject(SUBJECT)
                .claim("head_img",user.getHeadImg())
                .claim("id",user.getId())
                .claim("name",user.getName())
                .setIssuedAt(new Date())
                .setExpiration(new Date(System.currentTimeMillis() + EXPIRE))
                .signWith(SignatureAlgorithm.HS256,SECRET).compact();

        token = TOKEN_PREFIX + token;


        return token;
    }


    /**
     * 校验token的方法
     * @param token
     * @return
     */
    public static Claims checkJWT(String token){
    
    

        try{
    
    

            final  Claims claims = Jwts.parser().setSigningKey(SECRET)
                    .parseClaimsJws(token.replace(TOKEN_PREFIX,"")).getBody();

            return claims;

        }catch (Exception e){
    
    
            return null;
        }

    }



}

5、异常处理类

先自定义了一个异常处理类

package net.xdclass.online_xdclass.exception;

/**
 * 小滴课堂
 * 自定义异常类
 */
public class XDException extends RuntimeException{
    
    

    private Integer code;

    private String msg;

    public XDException(Integer code, String msg){
    
    
        this.code = code;
        this.msg = msg;
    }

    public Integer getCode() {
    
    
        return code;
    }

    public void setCode(Integer code) {
    
    
        this.code = code;
    }

    public String getMsg() {
    
    
        return msg;
    }

    public void setMsg(String msg) {
    
    
        this.msg = msg;

    }
}

然后异常处理：

package net.xdclass.online_xdclass.exception;


import net.xdclass.online_xdclass.utils.JsonData;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseBody;

/**
 * 异常处理类
 */
@ControllerAdvice
public class CustomExceptionHandler {
    
    

    private final static Logger logger = LoggerFactory.getLogger(CustomExceptionHandler.class);

    @ExceptionHandler(value = Exception.class)
    @ResponseBody
    public JsonData handle(Exception e){
    
    

        logger.error("[ 系统异常 ]{}",e.getMessage());

        if( e instanceof XDException ){
    
    

            XDException xdException = (XDException) e;

            return JsonData.buildError(xdException.getCode(),xdException.getMsg());

        }else {
    
    

            return JsonData.buildError("全局异常，未知错误");

        }


    }

}

6、拦截器

https://blog.csdn.net/weixin_45678130/article/details/120779795