SpringBoot例外處理器的使用與新增員工功能實現流程介紹

@Slf4j
@WebFilter(filterName = "loginFilterCheck", urlPatterns = "/*")
public class LoginCheckFilter implements Filter {
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;
        log.info("攔截到請求：{}", request.getRequestURI());//{}相當於一個預留位置 可以實現動態變更
        filterChain.doFilter(request,response);
    }
}

        //獲取本次請求的uri
        String requestURI = request.getRequestURI();
        //定義不需要處理的資源路徑
        String[] urls=new String[]{
          "/employee/login",
                "/employee/logout",
                "/backend/**",
                "/front/**"
        };

    public boolean check(String[] urls,String requestURI){
        for (String url : urls) {
            boolean match = PATH_MATCHER.match(url, requestURI);
            if (match){
                return true;
            }
        }
        return false;
    }

        //判斷是否需要處理
        boolean check = check(urls, requestURI);
        //如果不需要處理就直接放行
        if (check){
            filterChain.doFilter(request,response);
            return;
        }

        //檢視登陸狀態 如果已登入 則直接放行
        if (!(request.getSession().getAttribute("employee") == null)) {
            filterChain.doFilter(request, response);
            return;
        }
        //如果未登入，則通過輸出流的方式向用戶端頁面響應資料
        response.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));

    @PostMapping //前端的請求路徑為employee,而上述@RequestMapping("/employee")已寫好
    public R<String> save(HttpServletRequest request, @RequestBody Employee employee) {
        log.info("新增員工：{}", employee.toString());
        //設定初始預設密碼
       employee.setPassword(DigestUtils.md5DigestAsHex("123456".getBytes()));
        //設定更新時間
        employee.setCreateTime(LocalDateTime.now());//建立時間
        employee.setUpdateTime(LocalDateTime.now());//更新時間
        //獲取當前登入使用者的id
        Long empID = (Long) request.getSession().getAttribute("employee");
        employee.setCreateUser(empID);
        employee.setUpdateUser(empID);
        return R.success("新增員工成功！");
    }

/**
 * 全域性例外處理
 */
@ControllerAdvice(annotations = {RestController.class, Controller.class}) //攔截有指定註解類的Controller
@Slf4j
@ResponseBody
public class GlobalExceptionHandler {
    /**
     * 例外處理方法，一旦Controller發生此異常就會被攔截到
     * @return
     */
    @ExceptionHandler({SQLIntegrityConstraintViolationException.class})
    public R<String>  excpHandler(SQLIntegrityConstraintViolationException exception) {//捕獲到的異常被傳到方法的形參裡
       log.info("異常資訊："+exception.getMessage());
        //細化新增失敗後的返回資訊
        if (exception.getMessage().contains("Duplicate entry")){
            String[] s = exception.getMessage().split(" ");
            String msg=s[2]+"已存在!";
            return R.error(msg);
        }
        return R.error("發生異常！新增失敗！");
    }
}