[WIP] Add practical session guide

meetings/practical-session-1.md

@@ -71,9 +71,10 @@ The IntelliJ IDEA channel on YouTube provides a great step-by-step guide on how
 
 > For the purposes of this practical session, cloning this repository into your machine and opening its root directory as an IntelliJ project will already configure most things for deployment. Still, create a web application first, such that IntelliJ has already the path to your Tomcat and JDK installations.
 
-["Tomcat in IntelliJ IDEA Ultimate" by Dalia Abo Sheasha![](http://img.youtube.com/vi/ThBw3WBTw9Q/0.jpg)](http://www.youtube.com/watch?v=ThBw3WBTw9Q)
+[![](http://img.youtube.com/vi/ThBw3WBTw9Q/0.jpg)](http://www.youtube.com/watch?v=ThBw3WBTw9Q)
+["Tomcat in IntelliJ IDEA Ultimate" by Dalia Abo Sheasha](http://www.youtube.com/watch?v=ThBw3WBTw9Q)
 
-<!-- <iframe width="560" height="315" src="https://www.youtube.com/embed/ThBw3WBTw9Q?si=wB7XiVdEC7KFN8kV" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen></iframe> -->
+<!-- ["Tomcat in IntelliJ IDEA Ultimate" by Dalia Abo Sheasha![](http://img.youtube.com/vi/ThBw3WBTw9Q/0.jpg)](http://www.youtube.com/watch?v=ThBw3WBTw9Q) -->
 
 After creating a project, please perform the following procedures:
 

pom.xml

@@ -7,7 +7,7 @@
     <groupId>nl.utwente.mod4</groupId>
     <artifactId>pokemon</artifactId>
     <version>1.0-SNAPSHOT</version>
-    <name>mod4-wp-2023-2024-pokemon</name>
+    <name>pokemon</name>
     <packaging>war</packaging>
 
     <properties>

src/main/java/nl/utwente/mod4/pokemon/Listenner.java

+package nl.utwente.mod4.pokemon;
+
+import jakarta.servlet.ServletContextEvent;
+import jakarta.servlet.ServletContextListener;
+import jakarta.servlet.annotation.WebListener;
+import nl.utwente.mod4.pokemon.dao.PokemonTypeDao;
+
+import java.io.IOException;
+
+@WebListener
+public class Listenner implements ServletContextListener {
+    @Override
+    public void contextInitialized(ServletContextEvent sce) {
+        System.out.println("Initializing PokeApp...");
+        try {
+            PokemonTypeDao.INSTANCE.load();
+        } catch (IOException e) {
+            System.err.println("Error while loading data.");
+            e.printStackTrace();
+        }
+        System.out.println("PokeApp initialized.");
+    }
+
+    @Override
+    public void contextDestroyed(ServletContextEvent sce) {
+        System.out.println("Shutting down PokeApp...");
+        try {
+            PokemonTypeDao.INSTANCE.save();
+        } catch (IOException e) {
+            System.err.println("Error while saving data.");
+            e.printStackTrace();
+        }
+        System.out.println("PokeApp shutdown.");
+    }
+}

src/main/java/nl/utwente/mod4/pokemon/PokemonTrainerDatabase.java → src/main/java/nl/utwente/mod4/pokemon/PokeApp.java

 package nl.utwente.mod4.pokemon;
 
-import jakarta.servlet.http.HttpServlet;
 import jakarta.ws.rs.ApplicationPath;
+import jakarta.ws.rs.core.Application;
 
-@ApplicationPath("/")
-public class PokemonTrainerDatabase extends HttpServlet {
-
+@ApplicationPath("/api")
+public class PokeApp extends Application {
 }
\ No newline at end of file

src/main/java/nl/utwente/mod4/pokemon/Utils.java

+package nl.utwente.mod4.pokemon;
+
+import java.nio.file.Path;
+
+public class Utils {
+
+    public static String getAbsolutePathToResources() {
+        return Utils.class.getClassLoader().getResource("").getPath();
+    }
+}

src/main/java/nl/utwente/mod4/pokemon/dao/PokemonTypeDao.java

 package nl.utwente.mod4.pokemon.dao;
 
+import com.fasterxml.jackson.core.util.DefaultPrettyPrinter;
 import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.ObjectWriter;
+import jakarta.ws.rs.BadRequestException;
+import jakarta.ws.rs.NotFoundException;
+import jakarta.ws.rs.WebApplicationException;
+import jakarta.ws.rs.core.Response;
+import nl.utwente.mod4.pokemon.Utils;
 import nl.utwente.mod4.pokemon.model.PokemonType;
 
 import java.io.File;
 import java.io.IOException;
-import java.util.ArrayList;
-import java.util.List;
+import java.time.Instant;
+import java.util.*;
 
-public class PokemonTypeDao {
+public enum PokemonTypeDao {
 
-    private static final String filePath = PokemonTypeDao.class.getClassLoader().getResource("/aggregated-and-filtered-pokemon-dataset.json").getPath();
+    INSTANCE;
 
-    public List<PokemonType> loadPokemonType() throws IOException {
+    private static final String ORIGINAL_POKEMON_TYPES = Utils.getAbsolutePathToResources() + "/aggregated-and-filtered-pokemon-dataset.json";
+    private static final String POKEMON_TYPES = Utils.getAbsolutePathToResources() + "/pokemon-types.json";
+
+    private HashMap<String, PokemonType> pokemonTypes = new HashMap<>();
+
+    public void delete(String id) {
+        if(pokemonTypes.containsKey(id)) {
+            pokemonTypes.remove(id);
+        } else {
+            throw new NotFoundException("Pokemon type '" + id + "' not found.");
+        }
+    }
+
+    public List<PokemonType> getPokemonTypes() {
+        return new ArrayList<>(pokemonTypes.values());
+    }
+
+    public PokemonType getPokemonType(String id) {
+        var pt = pokemonTypes.get(id);
+
+        if (pt == null) {
+            throw new NotFoundException("Pokemon '" + id + "' not found!");
+        }
+
+        return pt;
+    }
+
+    public void load() throws IOException {
         ObjectMapper mapper = new ObjectMapper();
-        return mapper.readValue(new File(filePath), new ArrayList<PokemonType>().getClass());
+        File source = existsPokemonTypes() ?
+                new File(POKEMON_TYPES) :
+                new File(ORIGINAL_POKEMON_TYPES);
+        PokemonType[] arr = mapper.readValue(source, PokemonType[].class);
+
+        Arrays.stream(arr).forEach(pt -> pokemonTypes.put(pt.id, pt));
     }
 
+    public void save() throws IOException {
+        ObjectMapper mapper = new ObjectMapper();
+        ObjectWriter writer = mapper.writer(new DefaultPrettyPrinter());
+        File destination = new File(POKEMON_TYPES);
+
+        writer.writeValue(destination, pokemonTypes.values());
+    }
+
+    private boolean existsPokemonTypes() {
+        File f = new File(POKEMON_TYPES);
+        return f.exists() && !f.isDirectory();
+    }
+
+    private int getMaxId() {
+        Set<String> ids = pokemonTypes.keySet();
+        return ids.isEmpty() ? 0 : ids.stream()
+                .map(Integer::parseInt)
+                .max(Integer::compareTo)
+                .get();
+    }
+
+
+    public PokemonType create(PokemonType newPokemonType) {
+        String nextId = "" + (getMaxId() + 1);
+
+        newPokemonType.id = nextId;
+        newPokemonType.created = Instant.now().toString();
+        newPokemonType.lastUpDate = Instant.now().toString();
+        pokemonTypes.put(nextId,newPokemonType);
+
+        return newPokemonType;
+    }
+
+    public PokemonType update(PokemonType updated) {
+        if(!updated.isValid())
+            throw new BadRequestException("Invalid pokemon type.");
+        if(pokemonTypes.get(updated.id) == null)
+            throw new NotFoundException("Pokemon type id '" + updated.id + "' not found.");
+
+        updated.lastUpDate = Instant.now().toString();
+        pokemonTypes.put(updated.id,updated);
+
+        return updated;
+    }
 }

src/main/java/nl/utwente/mod4/pokemon/model/NamedEntity.java

@@ -10,10 +10,14 @@ public class NamedEntity {
     public String lastUpDate;
 
     public NamedEntity() {
-        id = "0";
-        name = "Missingno";
-        created = Instant.now().toString();
-        lastUpDate = Instant.now().toString();
+        id = null;
+        name = null;
+        created = null;
+        lastUpDate = null;
+    }
+
+    public boolean isValid() {
+        return id != null && !id.isEmpty();
     }
 
 }

src/main/java/nl/utwente/mod4/pokemon/model/PokemonType.java

@@ -28,9 +28,9 @@ public class PokemonType extends NamedEntity {
         super();
         pokedexNumber = 0;
         generation = 0;
-        japaneseName = "";
-        classification = "";
-        abilities = new ArrayList<>();
+        japaneseName = null;
+        classification = null;
+        abilities = null;
         baseHeight = 0;
         baseWeight = 0;
         baseHp = 0;
@@ -41,7 +41,7 @@ public class PokemonType extends NamedEntity {
         baseSpeed = 0;
         captureRate = 0;
         isLegendary = false;
-        imgUrl = "";
+        imgUrl = null;
     }
 
 }

src/main/java/nl/utwente/mod4/pokemon/model/ResourceCollection.java

+package nl.utwente.mod4.pokemon.model;
+
+public class ResourceCollection {
+}

src/main/java/nl/utwente/mod4/pokemon/routes/PokemonTypeRoute.java

@@ -6,37 +6,45 @@ import jakarta.ws.rs.core.Response;
 import nl.utwente.mod4.pokemon.dao.PokemonTypeDao;
 import nl.utwente.mod4.pokemon.model.PokemonType;
 
-import java.io.IOException;
 import java.util.List;
 
 @Path("/pokemonTypes")
 public class PokemonTypeRoute {
 
     @GET
-    @Path("/")
     @Produces(MediaType.APPLICATION_JSON)
     public List<PokemonType> getPokemon() {
-        try {
-            return new PokemonTypeDao().loadPokemonType();
-        } catch (IOException e) {
-            throw new ServerErrorException(Response.status(500).build());
-        }
+        return PokemonTypeDao.INSTANCE.getPokemonTypes();
     }
 
-//    @POST
-//    @Path("/")
-//    @Produces(MediaType.APPLICATION_JSON)
-//    @Consumes(MediaType.APPLICATION_JSON)
-//    public String createPokemon() {
-//        return "Returning all pokemon types.";
-//    }
+    @POST
+    @Produces(MediaType.APPLICATION_JSON)
+    @Consumes(MediaType.APPLICATION_JSON)
+    public PokemonType createPokemon(PokemonType pokemonType) {
+        return PokemonTypeDao.INSTANCE.create(pokemonType);
+    }
 
     @GET
     @Path("/{id}")
     @Produces(MediaType.APPLICATION_JSON)
-    public nl.utwente.mod4.pokemon.model.PokemonType getPokemon(@PathParam("id") String id) {
-        var pokemon = new nl.utwente.mod4.pokemon.model.PokemonType();
-        pokemon.id = id;
-        return pokemon;
+    public PokemonType getPokemon(@PathParam("id") String id) {
+        return PokemonTypeDao.INSTANCE.getPokemonType(id);
+    }
+
+    @PUT
+    @Path("/{id}")
+    @Produces(MediaType.APPLICATION_JSON)
+    @Consumes(MediaType.APPLICATION_JSON)
+    public PokemonType updatePokemon(@PathParam("id") String id, PokemonType toUpdate) {
+        if(id == null || !id.equals(toUpdate.id))
+            throw new BadRequestException("Id mismatch.");
+
+        return PokemonTypeDao.INSTANCE.update(toUpdate);
+    }
+
+    @DELETE
+    @Path("/{id}")
+    public void deletePokemon(@PathParam("id") String id) {
+        PokemonTypeDao.INSTANCE.delete(id);
     }
 }
\ No newline at end of file

src/main/webapp/WEB-INF/web.xml

@@ -8,16 +8,4 @@
     <welcome-file-list>
         <welcome-file>index.html</welcome-file>
     </welcome-file-list>
-
-    <servlet>
-        <description>Pokemon Servlet</description>
-        <display-name>PokemonTrainerDatabase</display-name>
-        <servlet-name>PokemonTrainerDatabase</servlet-name>
-        <servlet-class>nl.utwente.mod4.pokemon.PokemonTrainerDatabase</servlet-class>
-    </servlet>
-
-    <servlet-mapping>
-        <servlet-name>PokemonTrainerDatabase</servlet-name>
-        <url-pattern>/pokemon</url-pattern>
-    </servlet-mapping>
 </web-app>
\ No newline at end of file

src/main/webapp/index.html

@@ -6,6 +6,8 @@
 </head>
 <body>
 <p>Hello there</p>
-<img src="/images/abra.png"/>
-</body>
+<img src="/pokemon/images/abra.png"/>
+<form action="/pokemon/api/pokemonTypes">
+    <input type="submit" value="Pokemon Types" />
+</form></body>
 </html>
\ No newline at end of file

src/main/webapp/other.html

-<!DOCTYPE html>
-<html lang="en">
-<head>
-    <meta charset="UTF-8">
-    <title>Title</title>
-</head>
-<body>
-<p>Hello there</p>
-<img src="images/abra.png"/>
-</body>
-</html>
\ No newline at end of file