Began java section

docs/java/basics/classes.md

@@ -0,0 +1,9 @@
+# Classes
+
+## Generics
+
+Generics allow you to create a class that can hold many different kinds of data types, and specify an upper bound for what kind of interfaces are allowed to be stored and manipulated.
+
+```java
+
+```

docs/java/basics/interfaces.md

@@ -0,0 +1,36 @@
+# Interfaces
+
+## Common Interfaces to Implement
+
+### Comparator
+
+Compares two instances of a class.
+
+```java
+class StudentGPAComparator implements Comparator<Student> {
+    @Override
+    public int compare(Student o1, Student o2) {
+        return (o1.gpa + o1.name).compareTo(o2.gpa + o2.name);
+    }
+}
+
+public static void main() {
+    Comparator<Student> gpaSorter = new StudentGPAComparator();
+    Arrays.sort(students, gpaSorter);
+    Arrays.sort(students, gpaSorter.reversed());
+}
+
+```
+
+### Comparable
+
+Similar to Comparator, except this is implemented directly on the classes you are comparing. Without specificing a type, you will receive an `Object` to your `compareTo` function.
+
+```java
+class Student implements Comparable<Student> {
+    @Override
+    public int compareTo(Student o) {
+        return this.name.compareTo(o.name);
+    }
+}
+```

docs/java/basics/types.md

@@ -0,0 +1 @@
+# Types

docs/java/sidebar.json

@@ -2,8 +2,10 @@
   {
     "text": "Basics",
     "items": [
-        { "text": "Introduction", "link": "/java/" }
+      { "text": "Introduction", "link": "/java/" },
+      { "text": "Types", "link": "/java/basics/types" },
+      { "text": "Classes", "link": "/java/basics/classes" },
+      { "text": "Interfaces", "link": "/java/basics/interfaces" }
     ]
   }
 ]
-