How can i test an angular js web application with selenium?

The below two expected conditions will probably do everything you need to make testing an angular site easy.

This one will be the most used expected condition you will have in your code:

public static ExpectedCondition angularHasFinishedProcessing() {
    return new ExpectedCondition<Boolean>() {
        @Override
        public Boolean apply(WebDriver driver) {
            String hasAngularFinishedScript = "var callback = arguments[arguments.length - 1];\n" +
                    "var el = document.querySelector('html');\n" +
                    "if (!window.angular) {\n" +
                    "    callback('false')\n" +
                    "}\n" +
                    "if (angular.getTestability) {\n" +
                    "    angular.getTestability(el).whenStable(function(){callback('true')});\n" +
                    "} else {\n" +
                    "    if (!angular.element(el).injector()) {\n" +
                    "        callback('false')\n" +
                    "    }\n" +
                    "    var browser = angular.element(el).injector().get('$browser');\n" +
                    "    browser.notifyWhenNoOutstandingRequests(function(){callback('true')});\n" +
                    "}";

            JavascriptExecutor javascriptExecutor = (JavascriptExecutor) driver;
            String isProcessingFinished = javascriptExecutor.executeAsyncScript(hasAngularFinishedScript).toString();

            return Boolean.valueOf(isProcessingFinished);
        }
    };
}

It will wait for angular to be in a state where it thinks that the site is ready for automated tests to go ahead (This is pretty much stolen from the protector code base and wrapped in Java). You will need to have a script timeout set for it to work though:

webdriver.manage().timeouts().setScriptTimeout(15, TimeUnit.SECONDS);

Finally if you are using angular animate to move things around on the screen you will want this:

public static ExpectedCondition angularAnimationsAreComplete() {
    return new ExpectedCondition<Boolean>() {
        @Override
        public Boolean apply(WebDriver driver) {
            int animatingElements = driver.findElements(By.className("ng-animate")).size();

            return animatingElements == 0;
        }
    };
}

Angular animate adds the class "ng-animate" to all elements it is moving around. This condition will wait until that class is not longer applied to any elements, or in other words it will wait until all the animations have completed.