diff --git a/index.wiki b/index.wiki
index faaf086..3d1112f 100644
--- a/index.wiki
+++ b/index.wiki
@@ -44,6 +44,7 @@ _Ideas.md and Classes.md are encrypted, so these links will not work_
 * [[tech/HTML|HTML]]
 * [[tech/CSS|CSS]]
 * [[tech/Javascript|Javascript]]
+* [[tech/Java|Java]]
 * [[tech/Solidity|Solidity]]
 * [[tech/PHP|PHP]]
 * [[tech/Rust|Rust]]
diff --git a/tech/Java.wiki b/tech/Java.wiki
new file mode 100644
index 0000000..0db4998
--- /dev/null
+++ b/tech/Java.wiki
@@ -0,0 +1,15 @@
+= Java =
+
+Java is a strongly typed, garbage collected language that runs in the JVM. It
+can run on almost anything.
+
+== Data structures ==
+
+| C++ DS | Java DS   | Notes                      |
+| Vector | ArrayList | Threadsafe                 |
+| Vector | Vector    | Not threadsafe; deprecated |
+| Deque  | Deque     |                            |
+| List   | ArrayList | Both linked lists          |
+| 
+
+