BAEL-2414 Guide to problem-spring-web (#6147)

* Fix issue with package name and folder name mismatch

* Add problem-spring-web code samples

* Use the latest version of the problem-spring-web library. Add spring security exceptions handling samples

* Fix issue with security configuration. Fix sample for forbidden operation

* Update ProblemDemoConfiguration.java

* Add integration tests to validate problems are correctly handled and responses are generated using the problem library

spring-boot-libraries/pom.xml

@@ -19,6 +19,10 @@
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-starter-web</artifactId>
 		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-security</artifactId>
+		</dependency>
 		<dependency>
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-starter-tomcat</artifactId>
@@ -29,6 +33,13 @@
 			<scope>test</scope>
 		</dependency>
 	
+		<!-- Problem Spring Web -->
+		<dependency>
+			<groupId>org.zalando</groupId>
+			<artifactId>problem-spring-web</artifactId>
+			<version>${problem-spring-web.version}</version>
+		</dependency>
+
 		<!-- ShedLock -->
 		<dependency>
 			<groupId>net.javacrumbs.shedlock</groupId>
@@ -139,6 +150,7 @@
 		<guava.version>18.0</guava.version>
 		<git-commit-id-plugin.version>2.2.4</git-commit-id-plugin.version>
 		<modelmapper.version>2.3.2</modelmapper.version>
+		<problem-spring-web.version>0.23.0</problem-spring-web.version>
 	</properties>
 
 </project>

spring-boot-libraries/src/main/java/com/baeldung/boot/Application.java

@@ -1,4 +1,4 @@
-package org.baeldung.boot;
+package com.baeldung.boot;
 
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;

spring-boot-libraries/src/main/java/com/baeldung/boot/problem/SpringProblemApplication.java

@@ -0,0 +1,19 @@
+package com.baeldung.boot.problem;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.autoconfigure.web.servlet.error.ErrorMvcAutoConfiguration;
+import org.springframework.context.annotation.ComponentScan;
+
+@SpringBootApplication
+@EnableAutoConfiguration(exclude = ErrorMvcAutoConfiguration.class)
+@ComponentScan("com.baeldung.boot.problem")
+public class SpringProblemApplication {
+
+    public static void main(String[] args) {
+        System.setProperty("spring.profiles.active", "problem");
+        SpringApplication.run(SpringProblemApplication.class, args);
+    }
+
+}

spring-boot-libraries/src/main/java/com/baeldung/boot/problem/advice/ExceptionHandler.java

@@ -0,0 +1,9 @@
+package com.baeldung.boot.problem.advice;
+
+import org.springframework.web.bind.annotation.ControllerAdvice;
+import org.zalando.problem.spring.web.advice.ProblemHandling;
+
+@ControllerAdvice
+public class ExceptionHandler implements ProblemHandling {
+
+}

spring-boot-libraries/src/main/java/com/baeldung/boot/problem/advice/SecurityExceptionHandler.java

@@ -0,0 +1,9 @@
+package com.baeldung.boot.problem.advice;
+
+import org.springframework.web.bind.annotation.ControllerAdvice;
+import org.zalando.problem.spring.web.advice.security.SecurityAdviceTrait;
+
+@ControllerAdvice
+public class SecurityExceptionHandler implements SecurityAdviceTrait {
+
+}

spring-boot-libraries/src/main/java/com/baeldung/boot/problem/configuration/ProblemDemoConfiguration.java

@@ -0,0 +1,17 @@
+package com.baeldung.boot.problem.configuration;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.zalando.problem.ProblemModule;
+import org.zalando.problem.validation.ConstraintViolationProblemModule;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+@Configuration
+public class ProblemDemoConfiguration {
+
+    @Bean
+    public ObjectMapper objectMapper() {
+        return new ObjectMapper().registerModules(new ProblemModule(), new ConstraintViolationProblemModule());
+    }
+}

spring-boot-libraries/src/main/java/com/baeldung/boot/problem/configuration/SecurityConfiguration.java

@@ -0,0 +1,31 @@
+package com.baeldung.boot.problem.configuration;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Import;
+import org.springframework.security.config.annotation.web.builders.HttpSecurity;
+import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
+import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
+import org.zalando.problem.spring.web.advice.security.SecurityProblemSupport;
+
+@Configuration
+@EnableWebSecurity
+@Import(SecurityProblemSupport.class)
+public class SecurityConfiguration extends WebSecurityConfigurerAdapter {
+
+    @Autowired
+    private SecurityProblemSupport problemSupport;
+
+    @Override
+    protected void configure(HttpSecurity http) throws Exception {
+        http.csrf().disable();
+        
+        http.authorizeRequests()
+            .antMatchers("/")
+            .permitAll();
+
+        http.exceptionHandling()
+            .authenticationEntryPoint(problemSupport)
+            .accessDeniedHandler(problemSupport);
+    }
+}

spring-boot-libraries/src/main/java/com/baeldung/boot/problem/controller/ProblemDemoController.java

@@ -0,0 +1,56 @@
+package com.baeldung.boot.problem.controller;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import org.springframework.http.MediaType;
+import org.springframework.security.access.AccessDeniedException;
+import org.springframework.web.bind.annotation.DeleteMapping;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.PutMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import com.baeldung.boot.problem.dto.Task;
+import com.baeldung.boot.problem.problems.TaskNotFoundProblem;
+
+@RestController
+@RequestMapping("/tasks")
+public class ProblemDemoController {
+
+    private static final Map<Long, Task> MY_TASKS;
+
+    static {
+        MY_TASKS = new HashMap<>();
+        MY_TASKS.put(1L, new Task(1L, "My first task"));
+        MY_TASKS.put(2L, new Task(2L, "My second task"));
+    }
+
+    @GetMapping(produces = MediaType.APPLICATION_JSON_VALUE)
+    public List<Task> getTasks() {
+        return new ArrayList<>(MY_TASKS.values());
+    }
+
+    @GetMapping(value = "/{id}", produces = MediaType.APPLICATION_JSON_VALUE)
+    public Task getTasks(@PathVariable("id") Long taskId) {
+        if (MY_TASKS.containsKey(taskId)) {
+            return MY_TASKS.get(taskId);
+        } else {
+            throw new TaskNotFoundProblem(taskId);
+        }
+    }
+
+    @PutMapping("/{id}")
+    public void updateTask(@PathVariable("id") Long id) {
+        throw new UnsupportedOperationException();
+    }
+
+    @DeleteMapping("/{id}")
+    public void deleteTask(@PathVariable("id") Long id) {
+        throw new AccessDeniedException("You can't delete this task");
+    }
+
+}

spring-boot-libraries/src/main/java/com/baeldung/boot/problem/dto/Task.java

@@ -0,0 +1,32 @@
+package com.baeldung.boot.problem.dto;
+
+public class Task {
+
+    private Long id;
+    private String description;
+
+    public Task() {
+    }
+
+    public Task(Long id, String description) {
+        this.id = id;
+        this.description = description;
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public String getDescription() {
+        return description;
+    }
+
+    public void setDescription(String description) {
+        this.description = description;
+    }
+
+}

spring-boot-libraries/src/main/java/com/baeldung/boot/problem/problems/TaskNotFoundProblem.java

@@ -0,0 +1,16 @@
+package com.baeldung.boot.problem.problems;
+
+import java.net.URI;
+
+import org.zalando.problem.AbstractThrowableProblem;
+import org.zalando.problem.Status;
+
+public class TaskNotFoundProblem extends AbstractThrowableProblem {
+
+    private static final URI TYPE = URI.create("https://example.org/not-found");
+
+    public TaskNotFoundProblem(Long taskId) {
+        super(TYPE, "Not found", Status.NOT_FOUND, String.format("Task '%s' not found", taskId));
+    }
+
+}

spring-boot-libraries/src/main/resources/application-problem.properties

@@ -0,0 +1,3 @@
+spring.resources.add-mappings=false
+spring.mvc.throw-exception-if-no-handler-found=true
+spring.http.encoding.force=true

spring-boot-libraries/src/test/java/com/baeldung/boot/problem/controller/ProblemDemoControllerIntegrationTest.java

@@ -0,0 +1,75 @@
+package com.baeldung.boot.problem.controller;
+
+import static org.hamcrest.CoreMatchers.equalTo;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.delete;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.put;
+import static org.springframework.test.web.servlet.result.MockMvcResultHandlers.print;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.http.MediaType;
+import org.springframework.test.context.junit4.SpringRunner;
+import org.springframework.test.web.servlet.MockMvc;
+
+import com.baeldung.boot.problem.SpringProblemApplication;
+
+@RunWith(SpringRunner.class)
+@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.MOCK, classes = SpringProblemApplication.class)
+@AutoConfigureMockMvc
+public class ProblemDemoControllerIntegrationTest {
+
+    @Autowired
+    private MockMvc mockMvc;
+
+    @Test
+    public void whenRequestingAllTasks_thenReturnSuccessfulResponseWithArrayWithTwoTasks() throws Exception {
+        mockMvc.perform(get("/tasks").contentType(MediaType.APPLICATION_JSON_VALUE))
+            .andDo(print())
+            .andExpect(jsonPath("$.length()", equalTo(2)))
+            .andExpect(status().isOk());
+    }
+
+    @Test
+    public void whenRequestingExistingTask_thenReturnSuccessfulResponse() throws Exception {
+        mockMvc.perform(get("/tasks/1").contentType(MediaType.APPLICATION_JSON_VALUE))
+            .andDo(print())
+            .andExpect(jsonPath("$.id", equalTo(1)))
+            .andExpect(status().isOk());
+    }
+
+    @Test
+    public void whenRequestingMissingTask_thenReturnNotFoundProblemResponse() throws Exception {
+        mockMvc.perform(get("/tasks/5").contentType(MediaType.APPLICATION_PROBLEM_JSON_VALUE))
+            .andDo(print())
+            .andExpect(jsonPath("$.title", equalTo("Not found")))
+            .andExpect(jsonPath("$.status", equalTo(404)))
+            .andExpect(jsonPath("$.detail", equalTo("Task '5' not found")))
+            .andExpect(status().isNotFound());
+    }
+
+    @Test
+    public void whenMakePutCall_thenReturnNotImplementedProblemResponse() throws Exception {
+        mockMvc.perform(put("/tasks/1").contentType(MediaType.APPLICATION_PROBLEM_JSON_VALUE))
+            .andDo(print())
+            .andExpect(jsonPath("$.title", equalTo("Not Implemented")))
+            .andExpect(jsonPath("$.status", equalTo(501)))
+            .andExpect(status().isNotImplemented());
+    }
+
+    @Test
+    public void whenMakeDeleteCall_thenReturnForbiddenProblemResponse() throws Exception {
+        mockMvc.perform(delete("/tasks/2").contentType(MediaType.APPLICATION_PROBLEM_JSON_VALUE))
+            .andDo(print())
+            .andExpect(jsonPath("$.title", equalTo("Forbidden")))
+            .andExpect(jsonPath("$.status", equalTo(403)))
+            .andExpect(jsonPath("$.detail", equalTo("You can't delete this task")))
+            .andExpect(status().isForbidden());
+    }
+
+}