package org.springframework.web.servlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import org.jspecify.annotations.Nullable;
public interface HandlerInterceptor {
    default boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        return true;
    }
    default void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, @Nullable ModelAndView modelAndView) throws Exception {
    }
    default void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, @Nullable Exception ex) throws Exception {
    }
}

package com.yang.test2_22_1.config;
import com.yang.test2_22_1.interceptor.LoginInterceptor;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
@Configuration
public class WebConfig implements WebMvcConfigurer {
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(new LoginInterceptor()).addPathPatterns("/**");
    }
}

@Configuration
public class WebConfig implements WebMvcConfigurer {
    @Autowired
    private LoginInterceptor loginInterceptor;
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(loginInterceptor)
                .addPathPatterns("/**") // 攔截所有請求
                .excludePathPatterns("/api/login"); // 排除登錄請求，不攔截
    }
}

package com.yang.test2_22_1.controller;
import com.yang.test2_22_1.model.User;
import org.springframework.web.bind.annotation.*;
import java.util.HashMap;
import java.util.Map;
@RestController
@RequestMapping("/api")
public class LoginController {
    @PostMapping("/login")
    public Map<String, Object> processLogin(@RequestBody User user) {
        Map<String, Object> response = new HashMap<>();
        String validUsername = "admin";
        String validPassword = "password123";
        if (validUsername.equals(user.getUsername()) && validPassword.equals(user.getPassword())) {
            response.put("success", true);
            response.put("message", "登錄成功！歡迎回來，" + user.getUsername() + "。");
        } else {
            response.put("success", false);
            response.put("message", "用戶名或密碼錯(cuò)誤，請重試。");
        }
        return response;
    }
    @GetMapping("/secret")
    public String getSecretInfo() {
        return "這是一條機(jī)密信息，只有登錄后的用戶才能看到！";
    }
}

package com.yang.test2_22_1.interceptor;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import lombok.extern.slf4j.Slf4j;
import org.jspecify.annotations.Nullable;
import org.springframework.stereotype.Component;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
@Slf4j
@Component
public class LoginInterceptor implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        Object loginUser = request.getSession().getAttribute("LOGIN_USER");
        if (loginUser == null) {
            response.setStatus(HttpServletResponse.SC_ACCEPTED);
            response.setContentType("application/json;charset=UTF-8");
            response.getWriter().write("{\"error\": \"未登錄，請先登錄系統(tǒng)\"}");
            return false;
        }
        log.info("執(zhí)行 preHandle 方法");
        return true;
    }
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, @Nullable ModelAndView modelAndView) throws Exception {
        log.info("執(zhí)行 postHandle 方法");
    }
}

package com.yang.test2_22_1.config;
import com.yang.test2_22_1.interceptor.LoginInterceptor;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
@Configuration
public class WebConfig implements WebMvcConfigurer {
    @Autowired
    private LoginInterceptor loginInterceptor;
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(loginInterceptor)
                .addPathPatterns("/**")
                .excludePathPatterns("/api/login", "/api/secret");
    }
}

import com.example.demo.model.Result;
import org.springframework.core.MethodParameter;
import org.springframework.http.MediaType;
import org.springframework.http.server.ServerHttpRequest;
import org.springframework.http.server.ServerHttpResponse;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.servlet.mvc.method.annotation.ResponseBodyAdvice;
@ControllerAdvice
public class ResponseAdvice implements ResponseBodyAdvice {
    // 判斷是否執(zhí)行beforeBodyWrite方法（true=執(zhí)行，false=不執(zhí)行）
    @Override
    public boolean supports(MethodParameter returnType, Class converterType) {
        return true; // 對所有接口的返回結(jié)果都進(jìn)行統(tǒng)一封裝
    }
    // 對返回?cái)?shù)據(jù)進(jìn)行具體封裝處理
    @Override
    public Object beforeBodyWrite(Object body, MethodParameter returnType, 
                                  MediaType selectedContentType, Class selectedConverterType, 
                                  ServerHttpRequest request, ServerHttpResponse response) {
        return Result.success(body); // 調(diào)用Result工具類封裝數(shù)據(jù)
    }
}

// 獲取當(dāng)前執(zhí)行的控制器類
Class<?> declaringClass = returnType.getMethod().getDeclaringClass();
// 獲取當(dāng)前執(zhí)行的方法
Method method = returnType.getMethod();

package com.yang.test2_25_1.exception;
import com.yang.test2_25_1.common.ApiResponse;
import lombok.extern.slf4j.Slf4j;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RestControllerAdvice;
@Slf4j
@RestControllerAdvice
public class GlobalExceptionHandler {
    /**
     * 處理用戶未找到異常
     */
    @ExceptionHandler(UserNotFoundException.class)
    public ApiResponse<Void> handleUserNotFoundException(UserNotFoundException e) {
        log.warn("參數(shù)異常：{}", e.getMessage());
        return ApiResponse.error(404, e.getMessage());
    }
    /**
     * 處理參數(shù)異常
     */
    @ExceptionHandler(IllegalArgumentException.class)
    public ApiResponse<Void> handleIllegalArgumentException(IllegalArgumentException e) {
        log.warn("參數(shù)異常：{}", e.getMessage());
        return ApiResponse.error(400, e.getMessage());
    }
    /**
     * 處理所有異常
     */
    @ExceptionHandler(Exception.class)
    public ApiResponse<Void> handleException(Exception e) {
        log.error("系統(tǒng)內(nèi)部發(fā)生未知異常", e.getMessage());
        return ApiResponse.error(500, "服務(wù)器內(nèi)部開小差了，請稍后再試");
    }
}