Bael-3395: Spring optional path variables (#8106)

* initial test cases

* changes in @requestMapping

spring-mvc-java/src/main/java/com/baeldung/model/Article.java

@@ -0,0 +1,22 @@
+package com.baeldung.model;
+
+public class Article {
+
+    public static final Article DEFAULT_ARTICLE = new Article(12);
+
+    private Integer id;
+
+    public Article(Integer articleId) {
+        this.id = articleId;
+    }
+
+    public Integer getId() {
+        return id;
+    }
+    
+    @Override
+    public String toString() {
+        return "Article [id=" + id + "]";
+    }
+
+}

spring-mvc-java/src/main/java/com/baeldung/web/controller/optionalpathvars/ArticleViewerController.java

@@ -0,0 +1,25 @@
+package com.baeldung.web.controller.optionalpathvars;
+
+import static com.baeldung.model.Article.DEFAULT_ARTICLE;
+
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import com.baeldung.model.Article;
+
+@RestController
+public class ArticleViewerController {
+
+    @RequestMapping(value = {"/article", "/article/{id}"})
+    public Article getArticle(@PathVariable(name = "id") Integer articleId) {
+
+        if (articleId != null) {
+            return new Article(articleId);
+        } else {
+            return DEFAULT_ARTICLE;
+        }
+
+    }
+
+}

spring-mvc-java/src/main/java/com/baeldung/web/controller/optionalpathvars/ArticleViewerWithMapParamController.java

@@ -0,0 +1,29 @@
+package com.baeldung.web.controller.optionalpathvars;
+
+import static com.baeldung.model.Article.DEFAULT_ARTICLE;
+
+import java.util.Map;
+
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import com.baeldung.model.Article;
+
+@RestController
+@RequestMapping(value = "/mapParam")
+public class ArticleViewerWithMapParamController {
+
+    @RequestMapping(value = {"/article", "/article/{id}"})
+    public Article getArticle(@PathVariable Map<String, String> pathVarsMap) {
+
+        String articleId = pathVarsMap.get("id");
+                
+        if (articleId != null) {
+            return new Article(Integer.valueOf(articleId));
+        } else {
+            return DEFAULT_ARTICLE;
+        }
+    }
+
+}

spring-mvc-java/src/main/java/com/baeldung/web/controller/optionalpathvars/ArticleViewerWithOptionalParamController.java

@@ -0,0 +1,28 @@
+package com.baeldung.web.controller.optionalpathvars;
+
+import static com.baeldung.model.Article.DEFAULT_ARTICLE;
+
+import java.util.Optional;
+
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import com.baeldung.model.Article;;
+
+@RestController
+@RequestMapping("/optionalParam")
+public class ArticleViewerWithOptionalParamController {
+
+    @RequestMapping(value = {"/article", "/article/{id}"})
+    public Article getArticle(@PathVariable(name = "id") Optional<Integer> optionalArticleId) {
+
+        if(optionalArticleId.isPresent()) {
+            Integer articleId = optionalArticleId.get();
+            return new Article(articleId);
+        }else {
+            return DEFAULT_ARTICLE;
+        }
+    }
+    
+}

spring-mvc-java/src/main/java/com/baeldung/web/controller/optionalpathvars/ArticleViewerWithRequiredAttributeController.java

@@ -0,0 +1,26 @@
+package com.baeldung.web.controller.optionalpathvars;
+
+import static com.baeldung.model.Article.DEFAULT_ARTICLE;
+
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import com.baeldung.model.Article;;
+
+@RestController
+@RequestMapping(value = "/requiredAttribute")
+public class ArticleViewerWithRequiredAttributeController {
+
+    @RequestMapping(value = {"/article", "/article/{id}"})
+    public Article getArticle(@PathVariable(name = "id", required = false) Integer articleId) {
+
+        if (articleId != null) {
+            return new Article(articleId);
+        } else {
+            return DEFAULT_ARTICLE;
+        }
+
+    }
+    
+}

spring-mvc-java/src/main/java/com/baeldung/web/controller/optionalpathvars/ArticleViewerWithTwoSeparateMethodsController.java

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+package com.baeldung.web.controller.optionalpathvars;
+
+import static com.baeldung.model.Article.DEFAULT_ARTICLE;
+
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import com.baeldung.model.Article;
+
+@RestController
+@RequestMapping(value = "/seperateMethods")
+public class ArticleViewerWithTwoSeparateMethodsController {
+
+    @RequestMapping(value = "/article/{id}")
+    public Article getArticle(@PathVariable(name = "id") Integer articleId) {
+        
+        return new Article(articleId);        
+    }
+    
+    @RequestMapping(value = "/article")
+    public Article getDefaultArticle() {
+
+        return DEFAULT_ARTICLE;
+    }
+
+}