Post on 30-Dec-2015
Bare-knuckle web development
OdessaJohannes Brodwall, Chief scientist
Exilesoft Global
• Bare-knuckle philosophy• Demonstration of bare-
knuckle web in Java• Further directions
Part I:
The bare-knuckle philosophy
• High impact/low ceremony• Framework light
• Test-driven
High impact with low ceremony
Java web: Servlets, WebDriver, Jetty,
Mockito
Java SOAP: JOOX, HttpURLConnection
.NET web prototype: WebDriver + HttpListener
.NET web work-in-progress:
WebDriver + HttpSelfHostServer
Light on framework
Frameworks solve 80% of the job…
… and makes the rest 10 times as hard
“Why did Hibernate suddenly slow down?”
“How do I implement a custom SOAP header
with JAX-WS?”
“How to do X with Spring”
@AutoWire + package scan with 100s of beans
Test-driven
No more architecture than what’s needed
Fast feedback cycle – also in the future
Part II:
Demo: Phonebook web app
Test driving
WebDriver browser = createWebDriver();
browser.get(url);browser.findElement(By.linkText("Add contact")).click();
browser.findEleme(By.name("fullName")).sendKeys("Vader");browser.findEleme(By.name("phoneNumber")).sendKeys("27");browser.findEleme(By.name("saveContact")).click();
browser.findElement(By.linkText("Find contact")).click();browser.findElem(By.name("nameQuery")).sendKeys("vader");browser.findElement(By.name("nameQuery")).submit();
assertThat(browser.findElem(By.id("contacts")).getText()) .contains("555-33274-7827");
Server server = new Server(0);server.setHandler( new WebAppContext("src/main/webapp", "/contacts"));server.start();
int port = server.getConnectors()[0].getLocalPort();String url = "http://localhost:" + port + "/contacts";
<web-app version="2.5“>
<servlet> <servlet-name>contactServlet</servlet-name> <servlet-class> com.exilesoft.bareknuckleweb.ContactServlet </servlet-class></servlet>
<servlet-mapping> <servlet-name>contactServlet</servlet-name> <url-pattern>contact/*</url-pattern></servlet-mapping>
</web-app>
public class ContactServlet extends HttpServlet {}
@Testpublic void shouldShowAddForm() throws Exception { ContactServlet servlet = new ContactServlet(); HttpServletRequest req = mock(HttpServletRequest.class); HttpServletResponse resp = mock(HttpServletResponse.class); StringWriter html = new StringWriter();
when(resp.getWriter()).thenReturn(new PrintWriter(html)); when(req.getPathInfo()).thenReturn("/create.html");
servlet.doGet(req, resp);
verify(resp).setContentType("text/html"); assertThat(html.toString()) .contains("<form method='post'") .contains("<input type='text' name='fullName'") .contains("<input type='text' name='phoneNumber'") .contains("<input type='submit' name='createContact'");}
Refactoring
Part III:
Further directorions
Norwegian agricultural
authority
Java web application with an MVC architecture
Controllers:• Create a view
• Retrieve model from repo• Set model on view
• Render view
View example:
@Overridepublic void render(HttpServletResponse resp) throws IOException { Match document = $("html", head(), $("img").attr("src", "/sms-varsel/Sparebank1.jpg"), $("h1", "Internet bank simulator"), $("form").attr("method", "post").append( hiddenField(this.bankNum, "bankNum"), hiddenField(this.customerId, "customerId"), $("h2", "Set Mobile Phone Number"), phoneNumberField(this.phoneNumber), $("h2", "Account numbers"), accountNumbersField(this.accountNumbers), $("h2", "Payment account"), paymentAccountField(this.defaultAccount), $("h2", "Save changes"), $("div", $("input").attr("type", "submit").attr("value", "Store")).attr("name", "update"))); resp.setContentType("text/html"); resp.setCharacterEncoding("UTF-8"); resp.getWriter().write(document.toString());}
Match document = $("html", head(), $("img").attr("src", "/logo.jpg"), $("h1", “Page name"), $("form").attr("method", "post").append( hiddenField(this.bankNum, "bankNum"), hiddenField(this.customerId, "customerId"), $("h2", "Save changes"), $("div", $("input").attr("type", "submit") .attr("value", "Store")) .attr("name", "update")));
Norwegian Power Transmission
System Operator
Universal repository
Universal service
Commands and Queries
One domain model
No Spring – 100 KLOC
Single-jar deployment• Includes scripts
• Includes Jetty
public class StatnettWebServer { private final org.eclipse.jetty.server.Server server; public ContactWebServer(int port) { server = new Server(port); server.setHandler(new WebAppContext(“…", "/statnett")); }
void start() throws Exception { server.start(); }
String getUrl() { int port = server.getConnectors()[0].getLocalPort(); return "http://localhost:" + port + "/contacts"; }
public static void main(String[] args) throws Exception { StatnettWebServer server = new StatnettWebServer(10080); server.start(); System.out.println(server.getUrl()); }}
SpareBank1
10 web service clients
HttpURLConnection
JOOX
@Overridepublic String getCountryByIp(String ipAddress) throws Exception { Document soapRequest = soapElement("S:Envelope", $("S:Body", wsxElement("wsx:GetGeoIP", $("wsx:IPAddress", ipAddress)))); Document soapResponse endpoint.postRequest(getSOAPAction(), soapRequest); return $(soapResponse).xpath("/Envelope/Body/*") .xpath("GetGeoIPResult/CountryName").text();}
public Document postRequest(String soapAction, Document soapRequest) { HttpURLConnection conn = (HttpURLConnection) url.openConnection(); connection.setDoInput(true); connection.setDoOutput(true); connection.addRequestProperty("SOAPAction", soapAction); connection.addRequestProperty("Content-Type", "text/xml"); $(soapRequest).write(connection.getOutputStream());
int responseCode = connection.getResponseCode(); if (isErrorResponse(responseCode)) { String response = toString(connection.getErrorStream()); String responseContentType = connection.getContentType(); if (responseContentType.startsWith("text/xml")) { return response; } throw new ServiceCommunicationException( "On POST to " + url + ": " + responseCode + " " + connection.getResponseMessage() + ": " + response); } return $(connection.getInputStream()).document();d}
Conclusion:
YAGNI
Test-driven development
High investment in tests
Low investment in frameworks
Thank youjbr@exilesoft.com
http://johannesbrodwall.com
http://exilesoft.com
http://twitter.com/jhannes