BAEL-6058: extracting request header

spring-boot-modules/spring-boot-mvc-5/src/main/java/com/baeldung/requestheader/BuzzController.java

@@ -0,0 +1,21 @@
+package com.baeldung.requestheader;
+
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import com.baeldung.requestheader.interceptor.OperatorHolder;
+
+@RestController
+public class BuzzController {
+    private final OperatorHolder operatorHolder;
+
+    public BuzzController(OperatorHolder operatorHolder) {
+        this.operatorHolder = operatorHolder;
+    }
+
+    @GetMapping("buzz")
+    public String buzz() {
+        return "hello, " + operatorHolder.getOperator();
+    }
+
+}

spring-boot-modules/spring-boot-mvc-5/src/main/java/com/baeldung/requestheader/FooBarController.java

@@ -0,0 +1,22 @@
+package com.baeldung.requestheader;
+
+import javax.servlet.http.HttpServletRequest;
+
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestHeader;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+public class FooBarController {
+
+    @GetMapping("foo")
+    public String foo(HttpServletRequest request) {
+        String operator = request.getHeader("operator");
+        return "hello, " + operator;
+    }
+
+    @GetMapping("bar")
+    public String bar(@RequestHeader("operator") String operator) {
+        return "hello, " + operator;
+    }
+}

spring-boot-modules/spring-boot-mvc-5/src/main/java/com/baeldung/requestheader/HeaderInterceptorApplication.java

@@ -0,0 +1,15 @@
+package com.baeldung.requestheader;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.web.servlet.config.annotation.EnableWebMvc;
+
+@SpringBootApplication
+@EnableWebMvc
+public class HeaderInterceptorApplication {
+
+    public static void main(String[] args) {
+        SpringApplication.run(HeaderInterceptorApplication.class, args);
+    }
+
+}

spring-boot-modules/spring-boot-mvc-5/src/main/java/com/baeldung/requestheader/config/HeaderInterceptorConfig.java

@@ -0,0 +1,33 @@
+package com.baeldung.requestheader.config;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Scope;
+import org.springframework.context.annotation.ScopedProxyMode;
+import org.springframework.web.context.WebApplicationContext;
+import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
+import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
+
+import com.baeldung.requestheader.interceptor.OperatorHolder;
+import com.baeldung.requestheader.interceptor.OperatorInterceptor;
+
+@Configuration
+public class HeaderInterceptorConfig implements WebMvcConfigurer {
+
+    @Override
+    public void addInterceptors(final InterceptorRegistry registry) {
+        registry.addInterceptor(operatorInterceptor());
+    }
+
+    @Bean
+    public OperatorInterceptor operatorInterceptor() {
+        return new OperatorInterceptor(operatorHolder());
+    }
+
+    @Bean
+    @Scope(value = WebApplicationContext.SCOPE_REQUEST, proxyMode = ScopedProxyMode.TARGET_CLASS)
+    public OperatorHolder operatorHolder() {
+        return new OperatorHolder();
+    }
+
+}

spring-boot-modules/spring-boot-mvc-5/src/main/java/com/baeldung/requestheader/interceptor/OperatorHolder.java

@@ -0,0 +1,13 @@
+package com.baeldung.requestheader.interceptor;
+
+public class OperatorHolder {
+    private String operator;
+
+    public String getOperator() {
+        return operator;
+    }
+
+    public void setOperator(String operator) {
+        this.operator = operator;
+    }
+}

spring-boot-modules/spring-boot-mvc-5/src/main/java/com/baeldung/requestheader/interceptor/OperatorInterceptor.java

@@ -0,0 +1,22 @@
+package com.baeldung.requestheader.interceptor;
+
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+import org.springframework.web.servlet.HandlerInterceptor;
+
+public class OperatorInterceptor implements HandlerInterceptor {
+
+    private final OperatorHolder operatorHolder;
+
+    @Override
+    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
+        String operator = request.getHeader("operator");
+        operatorHolder.setOperator(operator);
+        return true;
+    }
+
+    public OperatorInterceptor(OperatorHolder operatorHolder) {
+        this.operatorHolder = operatorHolder;
+    }
+}

spring-boot-modules/spring-boot-mvc-5/src/test/java/com/baeldung/requestheader/HeaderInterceptorApplicationTest.java

@@ -0,0 +1,66 @@
+package com.baeldung.requestheader;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.result.MockMvcResultHandlers.print;
+
+import org.assertj.core.api.Assertions;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.mock.web.MockHttpServletResponse;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit.jupiter.SpringExtension;
+import org.springframework.test.context.web.WebAppConfiguration;
+import org.springframework.test.web.servlet.MockMvc;
+import org.springframework.test.web.servlet.setup.MockMvcBuilders;
+import org.springframework.web.context.WebApplicationContext;
+
+@ExtendWith(SpringExtension.class)
+@ContextConfiguration(classes = { HeaderInterceptorApplication.class })
+@WebAppConfiguration
+public class HeaderInterceptorApplicationTest {
+
+    @Autowired
+    private WebApplicationContext webApplicationContext;
+
+    private MockMvc mockMvc;
+
+    @BeforeEach
+    public void setup() {
+        this.mockMvc = MockMvcBuilders.webAppContextSetup(this.webApplicationContext)
+            .build();
+    }
+
+    @Test
+    public void givenARequestWithOperatorHeader_whenWeCallFooEndpoint_thenOperatorIsExtracted() throws Exception {
+        MockHttpServletResponse response = this.mockMvc.perform(get("/foo").header("operator", "John.Doe"))
+            .andDo(print())
+            .andReturn()
+            .getResponse();
+
+        assertThat(response.getContentAsString()).isEqualTo("hello, John.Doe");
+    }
+
+    @Test
+    public void givenARequestWithOperatorHeader_whenWeCallBarEndpoint_thenOperatorIsExtracted() throws Exception {
+        MockHttpServletResponse response = this.mockMvc.perform(get("/bar").header("operator", "John.Doe"))
+            .andDo(print())
+            .andReturn()
+            .getResponse();
+
+        assertThat(response.getContentAsString()).isEqualTo("hello, John.Doe");
+    }
+
+    @Test
+    public void givenARequestWithOperatorHeader_whenWeCallBuzzEndpoint_thenOperatorIsIntercepted() throws Exception {
+        MockHttpServletResponse response = this.mockMvc.perform(get("/buzz").header("operator", "John.Doe"))
+            .andDo(print())
+            .andReturn()
+            .getResponse();
+
+        assertThat(response.getContentAsString()).isEqualTo("hello, John.Doe");
+    }
+
+}