Added a Java Class

Calculator.java

@@ -0,0 +1,8 @@
+package Git.JAVA;
+
+public class Calculator {
+    public double add(int a, int b) { return a + b; }
+    public double subtract(int a, int b) { return a - b; }
+    public double multiply(int a, int b) { return a * b; }
+    public double divide(int a, int b) { return a / (double)b; }
+}

Student.java

@@ -0,0 +1,15 @@
+public class Student {
+    private String name;
+    private int age;
+
+    public Student(String name, int age) {
+        this.name = name;
+        this.age = age;
+    }
+
+    public String getName() { return name; }
+    public void setName(String name) { this.name = name; }
+
+    public int getAge() { return age; }
+    public void setAge(int age) { this.age = age; }
+}