BAEL-4243:Once per request filter (#11239)

* executing junit via command line

* incorporating review comments

* incorporating review comments

* OncePerReqFilter

* Delete FirstUnitTest.java

* Delete SecondUnitTest.java

* Delete pom.xml

* Reverting

* Update pom.xml

* OncePerReqFilter

* Update MyFilter.java

* OncePerReqFilter

* OncePerReqFilter

* Update pom.xml

* Update pom.xml

* Update pom.xml

* fixing extra changes

* OncePerReqFilter

* Reverting

* Update MyOncePerRequestFilter.java

* Update HelloController.java

* fromatting changes

* fromatting changes

* formatting

* Apply suggestions from code review

Co-authored-by: KevinGilmore <kpg102@gmail.com>

* OncePerRequest changes

* OncePerRequest changes

* OncePerRequest changes

* OncePerRequest changes

* OncePerRequest changes

Co-authored-by: KevinGilmore <kpg102@gmail.com>

spring-boot-modules/spring-boot-basic-customization-2/src/main/java/com/baeldung/onceperrequestfilter/AuthenticationFilter.java

@@ -0,0 +1,34 @@
+package com.baeldung.onceperrequestfilter;
+
+import org.springframework.stereotype.Component;
+import org.springframework.web.filter.OncePerRequestFilter;
+
+import javax.servlet.FilterChain;
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.io.IOException;
+
+@Component
+public class AuthenticationFilter extends OncePerRequestFilter {
+
+    @Override
+    protected void doFilterInternal(
+            HttpServletRequest request,
+            HttpServletResponse response,
+            FilterChain filterChain) throws
+            ServletException, IOException {
+        String usrName = request.getHeader("userName");
+        logger.info("Successfully authenticated user  " +
+                usrName);
+        filterChain.doFilter(request, response);
+    }
+    @Override
+    protected boolean shouldNotFilterAsyncDispatch() {
+        return false;
+    }
+    @Override
+    protected boolean shouldNotFilterErrorDispatch() {
+        return false;
+    }
+}

spring-boot-modules/spring-boot-basic-customization-2/src/main/java/com/baeldung/onceperrequestfilter/HelloController.java

@@ -0,0 +1,40 @@
+package com.baeldung.onceperrequestfilter;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.stereotype.Controller;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.context.request.async.DeferredResult;
+
+import javax.servlet.http.HttpServletResponse;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+
+@Controller
+public class HelloController implements AutoCloseable {
+
+    private final ExecutorService executorService = Executors.newCachedThreadPool();
+
+    private Logger logger = LoggerFactory.getLogger(HelloController.class);
+
+    @GetMapping(path = "/greeting")
+    public DeferredResult<String> hello(HttpServletResponse response) throws Exception {
+        DeferredResult<String> deferredResult = new DeferredResult<>();
+        executorService.submit(() -> perform(deferredResult));
+        return deferredResult;
+    }
+
+    private void perform(DeferredResult<String> dr) {
+        try {
+            Thread.sleep(10);
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+        dr.setResult("OK");
+    }
+
+    @Override
+    public void close() throws Exception {
+        executorService.shutdownNow();
+    }
+}

spring-boot-modules/spring-boot-basic-customization-2/src/main/java/com/baeldung/onceperrequestfilter/MyOncePerRequestFilter.java

@@ -0,0 +1,29 @@
+package com.baeldung.onceperrequestfilter;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.stereotype.Component;
+import org.springframework.web.filter.OncePerRequestFilter;
+
+import javax.servlet.FilterChain;
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.io.IOException;
+
+@Component
+public class MyOncePerRequestFilter extends OncePerRequestFilter {
+    private Logger logger = LoggerFactory.getLogger(MyOncePerRequestFilter.class);
+
+    @Override
+    protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain)
+            throws ServletException, IOException {
+        logger.info("Inside Once Per Request Filter originated by request {}", request.getRequestURI());
+        filterChain.doFilter(request, response);
+    }
+
+    @Override
+    protected boolean shouldNotFilterAsyncDispatch() {
+        return true;
+    }
+}

spring-boot-modules/spring-boot-basic-customization-2/src/main/java/com/baeldung/onceperrequestfilter/OncePerRequestFilterApp.java

@@ -0,0 +1,12 @@
+package com.baeldung.onceperrequestfilter;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+
+@SpringBootApplication(scanBasePackages = "com.baeldung.onceperrequestfilter")
+public class OncePerRequestFilterApp {
+    public static void main(String[] args) {
+        SpringApplication.run(OncePerRequestFilterApp.class, args);
+    }
+}