Add search engine.

src/main/java/org/codiki/posts/PostController.java

@@ -54,7 +54,9 @@ public class PostController {
 	public PostDTO getByKey(@PathVariable("postKey") final String pPostKey, 
 			final HttpServletResponse response) {
 		final PostDTO result = getByKeyAndSource(pPostKey, response);
-		result.setText(parserService.parse(result.getText()));
+		if(result != null) {
+			result.setText(parserService.parse(result.getText()));
+		}
 		return result;
 	}
 	
@@ -79,10 +81,9 @@ public class PostController {
 				.map(PostDTO::new).collect(Collectors.toList());
 	}
 	
-	@PostMapping("/search")
-	public List<Post> search() {
-		// TODO
-		return null;
+	@GetMapping("/search/{searchCriteria}")
+	public List<PostDTO> search(@PathVariable("searchCriteria") final String pSearchCriteria) {
+		return postService.search(pSearchCriteria);
 	}
 	
 	@GetMapping("/byCategory/{categoryId}")

src/main/java/org/codiki/posts/PostService.java

@@ -1,12 +1,18 @@
 package org.codiki.posts;
 
 import java.io.IOException;
+import java.util.Collections;
 import java.util.Date;
+import java.util.LinkedList;
+import java.util.List;
 import java.util.Optional;
+import java.util.stream.Collectors;
 
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
+import org.apache.commons.lang3.StringUtils;
+import org.codiki.core.entities.business.SearchEntity;
 import org.codiki.core.entities.dto.PostDTO;
 import org.codiki.core.entities.persistence.Category;
 import org.codiki.core.entities.persistence.Post;
@@ -19,6 +25,17 @@ import org.springframework.stereotype.Service;
 
 @Service
 public class PostService {
+	private static final int SCORE_TITLE = 50;
+
+	private static final int SCORE_DESCRIPTION = 5;
+
+	private static final int SCORE_TEXT = 1;
+
+	private static final int SCORE_CATEGORY = 30;
+
+	private static final int SCORE_AUTHOR_NAME = 40;
+
+	private static final int SCORE_AUTHOR_EMAIL = 40;
 	
 	@Autowired
 	private PostRepository postRepository;
@@ -96,4 +113,62 @@ public class PostService {
 			pResponse.sendError(HttpServletResponse.SC_NOT_FOUND);
 		}
 	}
+
+	public List<PostDTO> search(String pSearchCriteria) {
+		final String[] criteriasArray = pSearchCriteria.split(" ");
+		
+		final List<SearchEntity> listSearchEntities = new LinkedList<>();
+		postRepository.search(criteriasArray).stream().map(SearchEntity::new).forEach(e -> { 
+			calculateScore(e, criteriasArray);
+			listSearchEntities.add(e);
+		});
+		Collections.sort(listSearchEntities, (e1, e2) -> e1.getScore() - e2.getScore());
+		
+		return listSearchEntities.stream().map(SearchEntity::getPost).map(PostDTO::new).collect(Collectors.toList());
+	}
+	
+	void calculateScore(final SearchEntity searchPost, final String[] pCriteriasArray) {
+		for(final String criteria : pCriteriasArray) {
+			calculateScoreForTitle(searchPost, criteria);
+			calculateScoreForDescription(searchPost, criteria);
+			calculateScoreForText(searchPost, criteria);
+			calculateScoreForCategory(searchPost, criteria);
+			calculateScoreForAuthorName(searchPost, criteria);
+			calculateScoreForAuthorEmail(searchPost, criteria);
+		}
+	}
+	
+	private void calculateScoreForTitle(final SearchEntity pSearchPost, final String pCriteria) {
+		if(pSearchPost.getPost().getTitle().contains(pCriteria)) {
+			pSearchPost.increaseScore(SCORE_TITLE);
+		}
+	}
+	
+	private void calculateScoreForDescription(final SearchEntity pSearchPost, final String pCriteria) {
+		final int criteriaOccurence = StringUtils.countMatches(pSearchPost.getPost().getDescription(), pCriteria);
+		pSearchPost.increaseScore(criteriaOccurence * SCORE_DESCRIPTION);
+	}
+	
+	private void calculateScoreForText(final SearchEntity pSearchPost, final String pCriteria) {
+		final int criteriaOccurence = StringUtils.countMatches(pSearchPost.getPost().getText(), pCriteria);
+		pSearchPost.increaseScore(criteriaOccurence * SCORE_TEXT);
+	}
+	
+	private void calculateScoreForCategory(final SearchEntity pSearchPost, final String pCriteria) {
+		if(pSearchPost.getPost().getCategory().getName().contains(pCriteria)) {
+			pSearchPost.increaseScore(SCORE_CATEGORY);
+		}
+	}
+	
+	private void calculateScoreForAuthorName(final SearchEntity pSearchPost, final String pCriteria) {
+		if(pSearchPost.getPost().getAuthor().getName().contains(pCriteria)) {
+			pSearchPost.increaseScore(SCORE_AUTHOR_NAME);
+		}
+	}
+	
+	private void calculateScoreForAuthorEmail(final SearchEntity pSearchPost, final String pCriteria) {
+		if(pSearchPost.getPost().getAuthor().getEmail().contains(pCriteria)) {
+			pSearchPost.increaseScore(SCORE_AUTHOR_EMAIL);
+		}
+	}
 }