Woditschka

.gitignore

@@ -0,0 +1,2 @@
+.DS_Store
+.idea

software-engineer/pom.xml

@@ -5,7 +5,7 @@
     <modelVersion>4.0.0</modelVersion>
 
     <groupId>com.drmtx</groupId>
-    <artifactId>hiring-exerchise</artifactId>
+    <artifactId>hiring-exercise</artifactId>
     <version>1.0-SNAPSHOT</version>
 
     <parent>
@@ -48,6 +48,27 @@
             <version>1.4.187</version>
             <scope>runtime</scope>
         </dependency>
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-lang3</artifactId>
+            <version>3.4</version>
+        </dependency>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>4.12</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.hamcrest</groupId>
+            <artifactId>hamcrest-library</artifactId>
+            <version>1.3</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework</groupId>
+            <artifactId>spring-test</artifactId>
+        </dependency>
     </dependencies>
     <build>
         <plugins>
@@ -69,5 +90,4 @@
     </build>
 
 
-
 </project>

software-engineer/src/main/java/com/drmtx/app/Application.java

@@ -5,7 +5,6 @@
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
-import org.springframework.boot.orm.jpa.EntityScan;
 import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
@@ -15,30 +14,29 @@
 
 @EnableAutoConfiguration
 @SpringBootApplication
-@EntityScan(basePackageClasses=Application.class)
 @Configuration
 public class Application {
 
-  private static final Logger _logger = LogManager.getLogger(Application.class);
+    private static final Logger _logger = LogManager.getLogger(Application.class);
 
-  @Bean
-  protected ServletContextListener listener() {
-    return new ServletContextListener() {
+    @Bean
+    protected ServletContextListener listener() {
+        return new ServletContextListener() {
 
-      @Override
-      public void contextInitialized(ServletContextEvent sce) {
-        _logger.info("ServletContext initialized");
-      }
+            @Override
+            public void contextInitialized(ServletContextEvent sce) {
+                _logger.info("ServletContext initialized");
+            }
 
-      @Override
-      public void contextDestroyed(ServletContextEvent sce) {
-        _logger.info("ServletContext destroyed");
-      }
+            @Override
+            public void contextDestroyed(ServletContextEvent sce) {
+                _logger.info("ServletContext destroyed");
+            }
 
-    };
-  }
+        };
+    }
 
-  public static void main(String[] args) throws Exception {
-    ConfigurableApplicationContext applicationContext = SpringApplication.run(Application.class, args);
-  }
+    public static void main(String[] args) throws Exception {
+        ConfigurableApplicationContext applicationContext = SpringApplication.run(Application.class, args);
+    }
 }

software-engineer/src/main/java/com/drmtx/app/domain/WordFrequency.java

@@ -0,0 +1,63 @@
+package com.drmtx.app.domain;
+
+import com.drmtx.app.domain.base.EntityBase;
+
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.Table;
+
+@Entity
+@Table(name = "word_frequency")
+public class WordFrequency extends EntityBase {
+
+    @Column(name = "request_id", nullable = true)
+    private String requestId;
+
+    @Column(name = "term", nullable = true)
+    private String term;
+
+    @Column(name = "term_count", nullable = true)
+    private int termCount;
+
+    public WordFrequency() {
+    }
+
+    public WordFrequency(String requestId, String term, int termCount) {
+        this.requestId = requestId;
+        this.term = term;
+        this.termCount = termCount;
+    }
+
+    public String getRequestId() {
+        return requestId;
+    }
+
+    public void setRequestId(String requestId) {
+        this.requestId = requestId;
+    }
+
+    public String getTerm() {
+        return term;
+    }
+
+    public void setTerm(String term) {
+        this.term = term;
+    }
+
+    public int getTermCount() {
+        return termCount;
+    }
+
+    public void setTermCount(int termCount) {
+        this.termCount = termCount;
+    }
+
+    @Override
+    public String toString() {
+        return "WordFrequency{" +
+                "requestId='" + requestId + '\'' +
+                ", term='" + term + '\'' +
+                ", termCount=" + termCount +
+                '}';
+    }
+}

software-engineer/src/main/java/com/drmtx/app/domain/WordFrequencyAnalyzer.java

@@ -0,0 +1,65 @@
+package com.drmtx.app.domain;
+
+import org.apache.commons.lang3.StringUtils;
+
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import static java.util.function.Function.identity;
+import static java.util.stream.Collectors.*;
+
+/**
+ * Analyze the word frequency.
+ * <pre>
+ * - All whitespace characters should be ignored
+ * - All words should be converted to lower case
+ * - Following punctuation characters should be ignored: !,.?
+ * </pre>
+ */
+public class WordFrequencyAnalyzer {
+
+    /**
+     * Analyze a text for word frequencies.
+     *
+     * @param text the text to analyze
+     * @return the word frequencies
+     */
+    public Map<String, Integer> analyze(String text) {
+
+        // check for empty input
+        if (StringUtils.isBlank(text)) {
+            return new HashMap<>();
+        }
+
+        // split the text
+        List<String> words = Arrays.asList(text.toLowerCase().split("[\\s.,?\\t\\n\\r]"));
+
+        // calculate frequencies
+        return words.stream()
+                .filter(StringUtils::isNotBlank)
+                .collect(groupingBy(identity(), summingInt(e -> 1)));
+    }
+
+    /**
+     * Analyze multiple texts for word frequencies.
+     *
+     * @param texts     the texts to analyze
+     * @param requestId the  requestId
+     * @return the word frequencies
+     */
+    public List<WordFrequency> analyze(List<String> texts, String requestId) {
+        // merge all texts
+        String allTexts = texts.stream()
+                .collect(joining(" "));
+
+        // analyze word frequencies
+        Map<String, Integer> frequencies = analyze(allTexts);
+
+        // map result to model
+        return frequencies.entrySet().stream()
+                .map(e -> new WordFrequency(requestId, e.getKey(), e.getValue()))
+                .collect(toList());
+    }
+}

software-engineer/src/main/java/com/drmtx/app/domain/base/EntityBase.java

@@ -0,0 +1,92 @@
+package com.drmtx.app.domain.base;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import javax.persistence.*;
+import java.util.Date;
+
+/**
+ * Entity base class to handle technical details of id and versioning.
+ */
+@MappedSuperclass
+public abstract class EntityBase {
+
+    @Transient
+    protected Logger logger = LoggerFactory.getLogger(getClass());
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    @Column(name = "id", nullable = false)
+    private Long id;
+
+    @Column(name = "creation_ts", nullable = false)
+    private Date creationTS;
+
+    @Version
+    @Column(name = "version")
+    private Integer version;
+
+    protected EntityBase() {
+        creationTS = new Date();
+    }
+
+    protected EntityBase(Date creationTS) {
+        this.creationTS = creationTS;
+    }
+
+    protected void setId(final Long id) {
+        this.id = id;
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    public Date getCreationTS() {
+        return creationTS;
+    }
+
+    public void setCreationTS(Date createdAt) {
+        this.creationTS = createdAt;
+    }
+
+    protected void setVersion(final Integer version) {
+        this.version = version;
+    }
+
+    public Integer getVersion() {
+        return version;
+    }
+
+    public boolean isNew() {
+        return null == getId();
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+
+        if (null == obj) {
+            return false;
+        }
+
+        if (this == obj) {
+            return true;
+        }
+
+        if (!getClass().equals(obj.getClass())) {
+            return false;
+        }
+
+        EntityBase that = (EntityBase) obj;
+
+        return null != this.getId() && this.getId().equals(that.getId());
+    }
+
+    @Override
+    public int hashCode() {
+        int hashCode = 17;
+        hashCode += null == getId() ? 0 : getId().hashCode() * 31;
+        return hashCode;
+    }
+}

software-engineer/src/main/java/com/drmtx/app/domain/reddit/RedditComment.java

@@ -0,0 +1,28 @@
+package com.drmtx.app.domain.reddit;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Model root to access all comments from the reddit comments endpoint.
+ */
+public class RedditComment {
+    private RedditCommentNode[] commentNodes;
+
+    public RedditComment(RedditCommentNode... commentNodes) {
+        this.commentNodes = commentNodes;
+    }
+
+    /**
+     * Get comment bodies of all nodes, child and reply nodes.
+     *
+     * @return all comment bodies.
+     */
+    public List<String> bodies() {
+        List<String> bodies = new ArrayList<>();
+        for (RedditCommentNode commentNode : commentNodes) {
+            bodies.addAll(commentNode.bodies());
+        }
+        return bodies;
+    }
+}