Move routing-in-play -> play-framework

play-framework/introduction/app/models/StudentStore.java

@@ -0,0 +1,46 @@
+package models;
+
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+public class StudentStore {
+    private static StudentStore instance;
+    private Map<Integer, Student> students = new HashMap<>();
+
+    public static StudentStore getInstance() {
+        if (instance == null) {
+            instance = new StudentStore();
+        }
+        return instance;
+    }
+
+    public Student addStudent(Student student) {
+        int id = students.size();
+        student.setId(id);
+        students.put(id, student);
+        return student;
+    }
+
+    public Student getStudent(int id) {
+        return students.get(id);
+    }
+
+    public Set<Student> getAllStudents() {
+        return new HashSet<>(students.values());
+    }
+
+    public Student updateStudent(Student student) {
+        int id = student.getId();
+        if (students.containsKey(id)) {
+            students.put(id, student);
+            return student;
+        }
+        return null;
+    }
+
+    public boolean deleteStudent(int id) {
+        return students.remove(id) != null;
+    }
+}