add read one article

src/main/java/io/spring/JacksonCustomizations.java

@@ -0,0 +1,44 @@
+package io.spring;
+
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.databind.Module;
+import com.fasterxml.jackson.databind.SerializerProvider;
+import com.fasterxml.jackson.databind.module.SimpleModule;
+import com.fasterxml.jackson.databind.ser.std.StdSerializer;
+import org.joda.time.DateTime;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+import java.io.IOException;
+
+@Configuration
+public class JacksonCustomizations {
+
+    @Bean
+    public Module realWorldModules() {
+        return new RealWorldModules();
+    }
+
+    public static class RealWorldModules extends SimpleModule {
+        public RealWorldModules() {
+            addSerializer(DateTime.class, new DateTimeSerializer());
+        }
+    }
+
+    public static class DateTimeSerializer extends StdSerializer<DateTime> {
+
+        protected DateTimeSerializer() {
+            super(DateTime.class);
+        }
+
+        @Override
+        public void serialize(DateTime value, JsonGenerator gen, SerializerProvider provider) throws IOException {
+            if (value == null) {
+                gen.writeNull();
+            } else {
+                gen.writeString(value.toString());
+            }
+        }
+    }
+
+}

src/main/java/io/spring/api/ArticleApi.java

@@ -0,0 +1,30 @@
+package io.spring.api;
+
+import io.spring.api.exception.ResourceNotFoundException;
+import io.spring.application.article.ArticleData;
+import io.spring.application.article.ArticleQueryService;
+import io.spring.core.user.User;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.http.ResponseEntity;
+import org.springframework.security.core.annotation.AuthenticationPrincipal;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+@RequestMapping(path = "/articles/{slug}")
+public class ArticleApi {
+    private ArticleQueryService articleQueryService;
+
+    @Autowired
+    public ArticleApi(ArticleQueryService articleQueryService) {
+        this.articleQueryService = articleQueryService;
+    }
+
+    @GetMapping
+    public ResponseEntity<ArticleData> article(@PathVariable("slug") String slug,
+                                               @AuthenticationPrincipal User user) {
+        return articleQueryService.findBySlug(slug, user).map(ResponseEntity::ok).orElseThrow(ResourceNotFoundException::new);
+    }
+}

src/main/java/io/spring/api/exception/ResourceNotFoundException.java

@@ -0,0 +1,8 @@
+package io.spring.api.exception;
+
+import org.springframework.http.HttpStatus;
+import org.springframework.web.bind.annotation.ResponseStatus;
+
+@ResponseStatus(value = HttpStatus.NOT_FOUND)
+public class ResourceNotFoundException extends RuntimeException {
+}

src/main/java/io/spring/api/security/WebSecurityConfig.java

@@ -26,6 +26,7 @@ public class WebSecurityConfig extends WebSecurityConfigurerAdapter {
             .sessionManagement().sessionCreationPolicy(SessionCreationPolicy.STATELESS).and()
             .authorizeRequests()
             .antMatchers(HttpMethod.POST, "/users", "/users/login").permitAll()
+            .antMatchers(HttpMethod.GET, "/articles/**").permitAll()
             .anyRequest().authenticated();
 
         http.addFilterBefore(jwtTokenFilter(), UsernamePasswordAuthenticationFilter.class);

src/main/java/io/spring/application/article/ArticleQueryService.java

@@ -23,17 +23,35 @@ public class ArticleQueryService {
     }
 
     public Optional<ArticleData> findById(String id, User user) {
-        ArticleData articleData = articleReadService.ofId(id);
+        ArticleData articleData = articleReadService.findById(id);
         if (articleData == null) {
             return Optional.empty();
         } else {
+            if (user != null) {
+                fillExtraInfo(id, user, articleData);
+            }
+            return Optional.of(articleData);
+        }
+    }
+
+    public Optional<ArticleData> findBySlug(String slug, User user) {
+        ArticleData articleData = articleReadService.findBySlug(slug);
+        if (articleData == null) {
+            return Optional.empty();
+        } else {
+            if (user != null) {
+                fillExtraInfo(articleData.getId(), user, articleData);
+            }
+            return Optional.of(articleData);
+        }
+    }
+
+    private void fillExtraInfo(String id, User user, ArticleData articleData) {
         articleData.setFavorited(articleFavoritesQueryService.isUserFavorite(user.getId(), id));
         articleData.setFavoritesCount(articleFavoritesQueryService.articleFavoriteCount(id));
         articleData.getProfileData().setFollowing(
             userRelationshipQueryService.isUserFollowing(
                 user.getId(),
                 articleData.getProfileData().getId()));
-            return Optional.of(articleData);
-        }
     }
 }

src/main/java/io/spring/application/article/ArticleReadService.java

@@ -7,5 +7,7 @@ import org.springframework.stereotype.Component;
 @Component
 @Mapper
 public interface ArticleReadService {
-    ArticleData ofId(@Param("id") String id);
+    ArticleData findById(@Param("id") String id);
+
+    ArticleData findBySlug(@Param("slug") String slug);
 }

src/main/resources/mapper/ArticleReadService.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8" ?>
 <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
 <mapper namespace="io.spring.application.article.ArticleReadService">
-    <select id="ofId" resultMap="articleData">
+    <sql id="selectArticleData">
         select
         A.id articleId,
         A.slug articleSlug,
@@ -20,8 +20,16 @@
         left join article_tags AT on A.id = AT.article_id
         left join tags T on T.id = AT.article_id
         left join users U on U.id = A.user_id
+    </sql>
+
+    <select id="findById" resultMap="articleData">
+        <include refid="selectArticleData"/>
         where A.id = #{id}
     </select>
+    <select id="findBySlug" resultMap="articleData">
+        <include refid="selectArticleData"/>
+        where A.slug = #{slug}
+    </select>
 
     <resultMap id="articleData" type="io.spring.application.article.ArticleData">
         <id column="articleId" property="id"/>

src/test/java/io/spring/api/ArticlesApiTest.java

@@ -24,6 +24,7 @@ import static io.restassured.RestAssured.given;
 import static org.hamcrest.core.IsEqual.equalTo;
 import static org.junit.Assert.*;
 import static org.mockito.Matchers.any;
+import static org.mockito.Matchers.anyString;
 import static org.mockito.Matchers.eq;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
@@ -131,4 +132,44 @@ public class ArticlesApiTest extends TestWithCurrentUser {
             }});
         }};
     }
+
+    @Test
+    public void should_read_article_success() throws Exception {
+        String slug = "test-new-article";
+        Article article = new Article(slug, "Test New Article", "Desc", "Body", new String[]{"java", "spring", "jpg"}, user.getId());
+
+        DateTime time = new DateTime();
+        ArticleData articleData = new ArticleData(
+            article.getId(),
+            article.getSlug(),
+            article.getTitle(),
+            article.getDescription(),
+            article.getBody(),
+            false,
+            0,
+            time,
+            time,
+            Arrays.asList("joda"),
+            new ProfileData(user.getId(), user.getUsername(), user.getBio(), user.getImage(), false));
+
+        when(articleQueryService.findBySlug(eq(slug), eq(null))).thenReturn(Optional.of(articleData));
+
+        RestAssured.when()
+            .get("/articles/{slug}", slug)
+            .then()
+            .statusCode(200)
+            .body("article.slug", equalTo(slug))
+            .body("article.body", equalTo(articleData.getBody()))
+            .body("article.createdAt", equalTo(time.toDateTimeISO().toString()));
+
+    }
+
+    @Test
+    public void should_404_if_article_not_found() throws Exception {
+        when(articleQueryService.findBySlug(anyString(), any())).thenReturn(Optional.empty());
+        RestAssured.when()
+            .get("/articles/not-exists")
+            .then()
+            .statusCode(404);
+    }
 }