تنفيذ مرشّح JWT مخصّص
أنشئ `OncePerRequestFilter` مخصّصًا لاعتراض الطلبات واستخراج JWTs ومصادقة المستخدمين.
تنفيذ مرشّح JWT مخصّص درس مجاني في Spring Security 6 & JWT Authentication على CoddyKit. هذا هو الدرس 2 من أصل 4. يمكنك قراءة الدرس كاملاً أدناه مجاناً — ثم تمرن عليه مباشرة في المتصفح باستخدام محرر أكواد مدمج ومدرس ذكاء اصطناعي متاح 24/7. هذا الدرس جزء من مسار التعلم في Spring Security 6 & JWT Authentication، وتقدمك يتزامن عبر الويب وتطبيق CoddyKit. تتضمن دورة Spring Security 6 & JWT Authentication 4 دروس في المجموع.
بعض أجزاء هذا الدرس لم تُترجم بعد وتظهر باللغة الإنجليزية.
Why a Custom JWT Filter?
When using JSON Web Tokens (JWTs) for authentication, Spring Security doesn't inherently know how to process them. This is where a custom filter comes in!
A custom JWT filter intercepts incoming requests to:
- Extract the JWT.
- Validate its authenticity and expiration.
- Inform Spring Security about the authenticated user.
The OncePerRequestFilter Base
For our custom JWT filter, we'll extend Spring's OncePerRequestFilter. This base class guarantees that your filter logic runs exactly once per HTTP request, preventing redundant processing.
- It simplifies filter implementation.
- Ensures efficiency for each request.
- It's ideal for authentication logic.
Basic Filter Structure
Every custom filter extending OncePerRequestFilter must override the doFilterInternal method. This is where our JWT processing logic will reside.
It provides access to the HttpServletRequest, HttpServletResponse, and the FilterChain to pass the request along.
import jakarta.servlet.FilterChain;
import jakarta.servlet.ServletException;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import org.springframework.web.filter.OncePerRequestFilter;
import java.io.IOException;
public class JwtAuthenticationFilter extends OncePerRequestFilter {
@Override
protected void doFilterInternal(
HttpServletRequest request,
HttpServletResponse response,
FilterChain filterChain
) throws ServletException, IOException {
// Our JWT logic will go here
filterChain.doFilter(request, response);
}
}Extracting the JWT
The first step in our filter is to extract the JWT from the incoming request. JWTs are typically sent in the Authorization header, prefixed with Bearer .
We need to check for this header and remove the 'Bearer ' part to get the raw token.
import jakarta.servlet.FilterChain;
import jakarta.servlet.ServletException;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import org.springframework.web.filter.OncePerRequestFilter;
import java.io.IOException;
public class JwtAuthenticationFilter extends OncePerRequestFilter {
@Override
protected void doFilterInternal(
HttpServletRequest request,
HttpServletResponse response,
FilterChain filterChain
) throws ServletException, IOException {
final String authHeader = request.getHeader("Authorization");
String jwt = null;
if (authHeader != null && authHeader.startsWith("Bearer ")) {
jwt = authHeader.substring(7); // Remove "Bearer " prefix
System.out.println("Extracted JWT: " + jwt.substring(0, 5) + "...");
} else {
System.out.println("No JWT found or invalid header.");
}
filterChain.doFilter(request, response);
}
}Validating & Parsing (Concept)
After extraction, the JWT must be validated. This involves:
- Signature verification: Ensuring the token hasn't been tampered with.
- Expiration check: Confirming the token is still valid.
- Claim extraction: Retrieving information like the username (subject) from the token's payload.
This validation is typically handled by a dedicated JwtService or similar utility, which our filter would use.
Loading User Details (Concept)
Once the JWT is validated and the username (or user ID) is extracted, the filter needs to load the user's specific details. This is usually done using Spring Security's UserDetailsService.
The UserDetailsService fetches the UserDetails object, which contains information like roles and authorities needed for authorization.
Setting Authentication Context
The final crucial step is to inform Spring Security that the user is authenticated for the current request. This is done by creating an Authentication object (e.g., UsernamePasswordAuthenticationToken) and setting it in the SecurityContextHolder.
Once set, Spring Security will recognize the user as authenticated for the duration of the request.
import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.security.core.userdetails.User;
import org.springframework.security.core.userdetails.UserDetails;
import java.util.ArrayList;
public class Main {
public static void main(String[] args) {
// Simulate a UserDetails object loaded from DB
UserDetails userDetails = new User(
"exampleUser", "[PASSWORD_HASH]", new ArrayList<>()
);
// Create an Authentication token
UsernamePasswordAuthenticationToken authToken =
new UsernamePasswordAuthenticationToken(
userDetails, null, userDetails.getAuthorities()
);
// Set the Authentication in the SecurityContextHolder
SecurityContextHolder.getContext().setAuthentication(authToken);
System.out.println("Authentication set for: " +
SecurityContextHolder.getContext().getAuthentication().getName());
// Clear context after request (or for next test)
SecurityContextHolder.clearContext();
}
}Runnable Filter Logic Example
Let's see a simplified, runnable example that mimics the core logic of our custom JWT filter. It simulates extracting a token and setting authentication based on its presence.
This example uses mock components to show the flow without a full Spring Boot setup.
import java.util.HashMap;
import java.util.Map;
// Simulate Spring Security components needed for the filter logic
class MockSecurityContextHolder {
private static String authenticatedUser = null;
public static String getAuthentication() {
return authenticatedUser;
}
public static void setAuthentication(String user) {
authenticatedUser = user;
}
public static void clearContext() {
authenticatedUser = null;
}
}
public class Main {
// This method simulates the core logic of doFilterInternal
public static void simulateJwtFilter(Map<String, String> requestHeaders) {
System.out.println("--- Simulating JWT Filter Logic ---");
final String authHeader = requestHeaders.get("Authorization");
String jwt = null;
String username = null;
if (authHeader != null && authHeader.startsWith("Bearer ")) {
jwt = authHeader.substring(7);
// In a real app, this extracts username from JWT payload
username = "coddyuser"; // Simplified: assume "coddyuser" from a valid JWT
System.out.println("Filter: JWT found: " + jwt.substring(0, 5) + "...");
} else {
System.out.println("Filter: No JWT found or invalid header format.");
}
// Check if user is already authenticated
if (username != null && MockSecurityContextHolder.getAuthentication() == null) {
// Simulate JWT validation (signature, expiration, etc.)
boolean tokenValid = true; // Assume valid for this simple demo
if (tokenValid) {
// In a real filter, we'd load UserDetails and create an Authentication object
MockSecurityContextHolder.setAuthentication(username);
System.out.println("Filter: User '" + username + "' authenticated and context set.");
} else {
System.out.println("Filter: JWT validation failed.");
}
} else if (username != null && MockSecurityContextHolder.getAuthentication() != null) {
System.out.println("Filter: User '" + username + "' already authenticated for this request.");
}
// In a real filter, this would call filterChain.doFilter(...)
System.out.println("Filter: Request passed to next filter/handler.");
System.out.println("--- Filter Logic End ---");
}
public static void main(String[] args) {
// Scenario 1: Request with a valid JWT
Map<String, String> headers1 = new HashMap<>();
headers1.put("Authorization", "Bearer abc.def.ghi");
simulateJwtFilter(headers1);
System.out.println("Main: SecurityContext has authentication: " +
(MockSecurityContextHolder.getAuthentication() != null ? MockSecurityContextHolder.getAuthentication() : "None"));
MockSecurityContextHolder.clearContext(); // Clean up
System.out.println("\n");
// Scenario 2: Request without a JWT
Map<String, String> headers2 = new HashMap<>();
simulateJwtFilter(headers2);
System.out.println("Main: SecurityContext has authentication: " +
(MockSecurityContextHolder.getAuthentication() != null ? MockSecurityContextHolder.getAuthentication() : "None"));
MockSecurityContextHolder.clearContext(); // Clean up
}
}Integrating with Spring Security
After creating our JwtAuthenticationFilter, we need to register it with Spring Security's filter chain. This is typically done in your security configuration class (e.g., SecurityConfig) using HttpSecurity.
We use .addFilterBefore() to ensure our JWT filter runs before Spring Security's default authentication filters, like UsernamePasswordAuthenticationFilter.
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
import org.springframework.security.web.SecurityFilterChain;
import org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter;
// Assuming JwtAuthenticationFilter is defined elsewhere
class JwtAuthenticationFilter extends OncePerRequestFilter {
@Override
protected void doFilterInternal(jakarta.servlet.http.HttpServletRequest request, jakarta.servlet.http.HttpServletResponse response, jakarta.servlet.FilterChain filterChain) throws jakarta.servlet.ServletException, java.io.IOException {
// Simplified for config demo
filterChain.doFilter(request, response);
}
}
@Configuration
@EnableWebSecurity
public class SecurityConfig {
private final JwtAuthenticationFilter jwtAuthFilter;
// Inject our custom JWT filter
public SecurityConfig(JwtAuthenticationFilter jwtAuthFilter) {
this.jwtAuthFilter = jwtAuthFilter;
}
@Bean
public SecurityFilterChain securityFilterChain(HttpSecurity http) throws Exception {
http
.csrf(csrf -> csrf.disable()) // Disable CSRF for stateless APIs
.authorizeHttpRequests(auth -> auth
.requestMatchers("/api/auth/**").permitAll() // Public endpoints
.anyRequest().authenticated() // Secure all other requests
)
// Add our custom JWT filter BEFORE the default UsernamePasswordAuthenticationFilter
.addFilterBefore(jwtAuthFilter, UsernamePasswordAuthenticationFilter.class);
return http.build();
}
}Filter Chain Challenge
Consider the JwtAuthenticationFilter we've discussed. What are its key responsibilities in the Spring Security filter chain when handling JWT-based authentication?
Lesson Recap: Custom JWT Filter
In this lesson, we explored how to build a custom OncePerRequestFilter to handle JWT authentication in Spring Security.
- We learned to extract JWTs from the
Authorizationheader. - We understood the conceptual steps of validating the token and loading user details.
- We saw how to authenticate the user by setting the
SecurityContextHolder. - Finally, we covered how to integrate this filter into Spring Security's filter chain using
HttpSecurity.addFilterBefore().
This custom filter is crucial for integrating JWTs seamlessly into your secure Spring Boot applications.
الأسئلة الشائعة
هل درس «تنفيذ مرشّح JWT مخصّص» مجاني؟
نعم — نص درس «تنفيذ مرشّح JWT مخصّص» كامل متاح مجاناً هنا على الويب. لتمرينه بشكل تفاعلي (محرر أكواد مدمج ومدرس ذكاء اصطناعي متاح 24/7) وفتح باقي دورة Spring Security 6 & JWT Authentication، انتقل إلى CoddyKit PRO. تتضمن دورة Spring Security 6 & JWT Authentication 4 دروس في المجموع.
ماذا ستتعلم في «تنفيذ مرشّح JWT مخصّص»؟
أنشئ `OncePerRequestFilter` مخصّصًا لاعتراض الطلبات واستخراج JWTs ومصادقة المستخدمين. تتمرن على Spring Security 6 & JWT Authentication مع أكواد عملية تشغلها مباشرة في المتصفح، ومدرس ذكاء اصطناعي متاح 24/7 يجيب على أسئلتك أثناء عملك.
هل أحتاج إلى خبرة سابقة لأبدأ Spring Security 6 & JWT Authentication؟
لا تُشترط خبرة سابقة. Spring Security 6 & JWT Authentication على CoddyKit منظم للمبتدئين حتى المتقدمين، لذا يمكنك البدء من هنا أو من البداية والتقدم بسرعتك الخاصة. هذا هو الدرس 2 من أصل 4.
كم من الوقت يستغرق درس «تنفيذ مرشّح JWT مخصّص»؟
معظم دروس CoddyKit تستغرق حوالي 5–10 دقائق. كل منها موجز وتفاعلي، لذا تحرز تقدماً مستمراً وتستأنف من حيث توقفت عبر الويب والتطبيق.
هل يمكنني كتابة وتشغيل أكواد في درس Spring Security 6 & JWT Authentication هذا؟
نعم. كل درس في Spring Security 6 & JWT Authentication يتضمن محرر أكواد مدمج، لذا تكتب وتشغل أكواداً حقيقية مباشرة في متصفحك وتحصل على تعليقات فورية من الذكاء الاصطناعي — بدون إعداد محلي.
جميع الدروس في هذه الدورة
- تصميم تدفق مصادقة JWT
- تنفيذ مرشّح JWT مخصّص
- تكامل AuthenticationManager وموفّرات المصادقة
- معالجة أخطاء المصادقة ونقاط الدخول