Importing Java Classes in Clojure

Question

I seem to be doing something wrong. I've built clojure from git, and am invoking it thus:

java -cp clojure.jar clojure.main

I get the repl, and then I type:

(import 'java.lang.string)

and I get:

java.lang.ClassNotFoundException: java.lang.string (NO_SOURCE_FILE:1)

I'm trying this with lang.string since I assume it has to exist on the classpath somewhere. I've tried other libraries, all without much luck. What am I doing wrong?

Answer 1

Bleh, I think I found it. First of all the syntax should be:

(import java.lang.String)

Also notice it's String not string.

Answer 2

String should be capitalized, that's all.

user> (import 'java.lang.String)
java.lang.String

But everything in java.lang is already imported and available by default, so you shouldn't need to do this.

Answer 3

Btw in non repl exercises probably the best way to include Java classes is the ns macro.

(ns foo.bar
  (:refer-clojure :exclude [ancestors printf])
  (:require (clojure.contrib sql sql.tests))
  (:use (my.lib this that))
  (:import (java.util Date Timer Random)
           (java.sql Connection Statement)))