Added ability to retrieve categories.

src/main/java/fr/unistra/sil/erp/back/Config.java

@@ -16,5 +16,7 @@ public class Config {
     
     public static final String MAPPING_RETRIEVEALL = URL_PREFIX +
             "/retrieveAll";
+    public static final String MAPPING_GETCATEGORIES = URL_PREFIX +
+            "/retrieveCategories";
     
 }

src/main/java/fr/unistra/sil/erp/back/api/controller/ApiRetrieveCategoriesController.java

+/*
+ * CONTRAT DE LICENCE DE LOGICIEL LIBRE CeCILL-B
+ * https://cecill.info/licences/Licence_CeCILL-B_V1-fr.html
+ */
+package fr.unistra.sil.erp.back.api.controller;
+
+import static fr.unistra.sil.erp.back.Config.MAPPING_GETCATEGORIES;
+import fr.unistra.sil.erp.back.DatabaseSystem;
+import fr.unistra.sil.erp.back.api.model.Category;
+import fr.unistra.sil.erp.back.db.DatabaseConnectionException;
+import fr.unistra.sil.erp.back.db.DatabaseInterface;
+import java.util.List;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+/**
+ * REST controller for the category list.
+ * @author BEAUVAIS ANTOINE
+ */
+@RestController
+public class ApiRetrieveCategoriesController {
+    
+    @GetMapping(MAPPING_GETCATEGORIES)
+    public ResponseEntity<Object> getCategories() throws ApiServerErrorException
+    {
+        DatabaseInterface db;
+        try {
+            db = DatabaseSystem.getInstance();
+        } catch (DatabaseConnectionException ex) {
+            Logger.getLogger(ApiRetrieveCategoriesController.class.getName())
+                    .log(Level.SEVERE, "Failed to connect to database.", ex);
+            throw new ApiServerErrorException("Database failure.");
+        }
+        
+        List<Category> res = db.getCategories();
+        if(res == null)
+            throw new ApiServerErrorException("Database failure.");
+        
+        return new ResponseEntity<>(res, HttpStatus.OK);
+    }
+    
+}

src/main/java/fr/unistra/sil/erp/back/api/controller/ApiRetrieveInfoController.java

@@ -42,8 +42,8 @@ public class ApiRetrieveInfoController {
             db = DatabaseSystem.getInstance();
         } catch (DatabaseConnectionException ex) {
             Logger.getLogger(ApiRetrieveInfoController.class.getName()).log(
-                    Level.SEVERE, "Database failure.", ex);
-            throw new ApiServerErrorException("Failed to connect to database.");
+                    Level.SEVERE, "Could not connect to database.", ex);
+            throw new ApiServerErrorException("Database failure.");
         }
         
         List<Item> res;

src/main/java/fr/unistra/sil/erp/back/api/model/Category.java

+/*
+ * CONTRAT DE LICENCE DE LOGICIEL LIBRE CeCILL-B
+ * https://cecill.info/licences/Licence_CeCILL-B_V1-fr.html
+ */
+package fr.unistra.sil.erp.back.api.model;
+
+/**
+ * Category entity.
+ * 
+ * Categories allow the API caller to sort items by category.
+ * @author BEAUVAIS ANTOINE
+ */
+public class Category {
+    
+    /**
+     * The category's identifier.
+     */
+    private final int id;
+    
+    /**
+     * The category's name.
+     */
+    private final String name;
+    
+    /**
+     * Class constructor.
+     * @param id the category's identifier.
+     * @param name the category's name.
+     */
+    public Category(int id, String name)
+    {
+        this.id = id;
+        this.name = name;
+    }
+    
+    /**
+     * Returns the current category's identifier.
+     * @return the category's identifier.
+     */
+    public int getId()
+    {
+        return this.id;
+    }
+    
+    /**
+     * Returns the current category's name.
+     * @return the category's name.
+     */
+    public String getName()
+    {
+        return this.name;
+    }
+}

src/main/java/fr/unistra/sil/erp/back/db/DatabaseInterface.java

@@ -4,6 +4,7 @@
  */
 package fr.unistra.sil.erp.back.db;
 
+import fr.unistra.sil.erp.back.api.model.Category;
 import fr.unistra.sil.erp.back.api.model.Item;
 import java.util.List;
 
@@ -19,15 +20,22 @@ public interface DatabaseInterface {
     
     /**
      * Returns the list of all items.
-     * @return the list of all items.
+     * @return the list of all items, or null if an error occurred.
      */
     public List<Item> getAllItems();
     
     /**
      * Returns the list of all items for a given category.
      * @param category the category's identifier.
-     * @return the list of items.
+     * @return the list of items, or null if an error occurred.
      */
     public List<Item> getItemsFromCategory(int category);
     
+    /**
+     * Returns the list of all categories.
+     * 
+     * @return the list of categories, or null if an error occurred.
+     */
+    public List<Category> getCategories();
+    
 }

src/main/java/fr/unistra/sil/erp/back/db/DatabaseSQLiteImpl.java

@@ -4,6 +4,7 @@
  */
 package fr.unistra.sil.erp.back.db;
 
+import fr.unistra.sil.erp.back.api.model.Category;
 import fr.unistra.sil.erp.back.api.model.Item;
 import java.sql.Connection;
 import java.sql.DriverManager;
@@ -29,6 +30,9 @@ public class DatabaseSQLiteImpl implements DatabaseInterface {
     private static final String SQL_GETITEMSFROMCATEGORY = SQL_GETALLITEMS +
             " WHERE category = ?";
     
+    private static final String SQL_GETCATEGORIES =
+            "SELECT id, name FROM categories";
+    
     private Connection conn;
     
     public DatabaseSQLiteImpl()
@@ -47,7 +51,7 @@ public class DatabaseSQLiteImpl implements DatabaseInterface {
         ResultSet rs;
         try {
             stmt = this.conn.createStatement();
-            rs = stmt.executeQuery(SQL_GETALLITEMS);
+            rs = stmt.executeQuery(query);
         } catch (SQLException ex) {
             Logger.getLogger(DatabaseSQLiteImpl.class.getName()).log(
                     Level.SEVERE, "Failed to run query: " + query, ex);
@@ -130,5 +134,27 @@ public class DatabaseSQLiteImpl implements DatabaseInterface {
         
         return res;
     }
+
+    @Override
+    public List<Category> getCategories() {
+        ResultSet rs = this.query(SQL_GETCATEGORIES);
+        if(rs == null)
+            return null;
+        
+        List<Category> res = new ArrayList<>();
+        try {
+            while(rs.next())
+            {
+                Category c = new Category(rs.getInt("id"), rs.getString("name"));
+                res.add(c);
+            }
+        } catch (SQLException ex) {
+            Logger.getLogger(DatabaseSQLiteImpl.class.getName()).log(
+                    Level.SEVERE, "Failed to fetch results.", ex);
+            return null;
+        }
+        
+        return res;
+    }
     
 }