Занятие №11 курса по Java в компании 7bits.

1. Курс по Java, 2016
Servlet, JSP

2. Курс по Java, 2016
Servlet API

3. Курс по Java, 2016
javax.servlet.Servlet
import javax.servlet.GenericServlet;
public class MyServlet extends GenericServlet {
@Override
public void service(ServletRequest servletRequest,
ServletResponse servletResponse)
throws ServletException, IOException {
// do something
}
}

4. Курс по Java, 2016
javax.servlet.ServletRequest
String remoteAddress = servletRequest.getRemoteAddr();
String contentType = servletRequest.getContentType();
InputStream input = servletRequest.getInputStream();
String parameter = servletRequest.getParameter("name");
Object attribute = servletRequest.getAttribute("name");
servletRequest.setAttribute("name", attribute);

5. Курс по Java, 2016
javax.servlet.ServletResponse
servletResponse.setContentType("text/html");
servletResponse.setContentLength(256);
OutputStream output = servletResponse.getOutputStream();

6. Курс по Java, 2016
javax.servlet.http.HttpServlet
public class MyHttpServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException {
// process GET request
}
@Override
protected void doPost(HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException {
// process POST request
}

7. Курс по Java, 2016
javax.servlet.http.HttpServletRequest
String remoteAddress = request.getRemoteAddr();
String contentType = request.getContentType();
Reader reader = request.getReader();
String parameter = request.getParameter("name");
Object attribute = request.getAttribute("name");
request.setAttribute("name", attribute);
Cookie[] cookies = request.getCookies();
String proxiedClient = request.getHeader("X-Forwarded-For");
HttpSession session = request.getSession();

8. Курс по Java, 2016
javax.servlet.http.HttpSession
HttpSession session = request.getSession();
Object sessionAttribute = session.getAttribute("name");
session.setAttribute("name", sessionAttribute);

9. Курс по Java, 2016
javax.servlet.http.HttpServletResponse
response.setContentType("text/html");
response.setContentLength(256);
Writer writer = response.getWriter();
response.addCookie(new Cookie("name", "value"));
response.addHeader("X-My-Header", "value");
response.sendError(500, "Everything failed");
response.sendRedirect("/other-path");

10. Курс по Java, 2016
Servlet Container

11. Курс по Java, 2016
Apache Tomcat
Самый популярный Servlet/JSP контейнер
https://tomcat.apache.org/

12. Курс по Java, 2016
$CATALINA_HOME
├── bin
├── conf
├── lib
├── logs
├── webapps
│ ├── hello
│ │ ├── index.jsp
│ │ ├── META-INF
│ │ └── WEB-INF
│ │ ├── classes
│ │ │ └── it
│ │ │ └── sevenbits
│ │ │ └── example
│ │ │ └── hello
│ │ │ └── HelloWorldServlet.class
│ │ └── web.xml
│ ├── hello.war
│ └── ROOT
└── work

13. Курс по Java, 2016
WAR
Web Application aRchive
│ ├── hello.war
│ │ ├── index.jsp
│ │ ├── META-INF
│ │ └── WEB-INF
│ │ ├── classes
│ │ │ └── it
│ │ │ └── sevenbits
│ │ │ └── example
│ │ │ └── hello
│ │ │ └── HelloWorldServlet.class
│ │ └── web.xml

14. Курс по Java, 2016
War в Maven
<project>
<modelVersion>4.0.0</modelVersion>
<groupId>it.sevenbits.example</groupId>
<artifactId>hello</artifactId>
<packaging>war</packaging>
<version>1.0-SNAPSHOT</version>
<name>hello Maven Webapp</name>
<url>http://maven.apache.org</url>
<build>
<finalName>hello</finalName>
</build>
</project>

15. Курс по Java, 2016
Webapp в Maven
<dependencies>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>servlet-api</artifactId>
<version>2.5</version>
<scope>provided</scope>
</dependency>
</dependencies>

16. Курс по Java, 2016
Webapp в Maven

17. Курс по Java, 2016
web.xml
<web-app>
<display-name>Sample Web Application</display-name>
<servlet>
<servlet-name>HelloWorldServlet</servlet-name>
<servlet-class>
it.sevenbits.example.hello.HelloWorldServlet
</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>HelloWorldServlet</servlet-name>
<url-pattern>/world</url-pattern>
</servlet-mapping>
</web-app>

18. Курс по Java, 2016
Сборка веб приложения
mvn package
cp target/hello.war $CATALINA_HOME/webapps

19. Курс по Java, 2016
HelloWorldServlet
public class HelloWorldServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/plain");
PrintWriter out = response.getWriter();
out.println("Hello, world");
}
}

20. Курс по Java, 2016
JSP
Java Server Pages
Servlet наоборот

21. Курс по Java, 2016
hello_world.jsp
<!DOCTYPE html>
<html>
<head>
<title>Hello</title>
</head>
<body>
<h1>Hello, world!</h1>
</body>
</html>

22. Курс по Java, 2016
Model — View — Controller
MVC

23. Курс по Java, 2016
Model
● Атрибуты запроса
● Сессия

24. Курс по Java, 2016
View
JSP
<!DOCTYPE html>
<html>
<head>
<title>Hello <%=request.getAttribute("name")%></title>
</head>
<body>
<h1>Hello, <%=request.getAttribute("name")%>!</h1>
</body>
</html>

25. Курс по Java, 2016
Controller
Servlet
protected void doPost(HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException {
// model manipulations
String name = request.getParameter("name");
request.setAttribute("name", name);
// forward to view
RequestDispatcher dispatcher =
request.getRequestDispatcher("hello_name.jsp");
dispatcher.forward(request, response);
}

26. Курс по Java, 2016
Forward RequestDispatcher.forward(request, response)

27. Курс по Java, 2016
Redirect HttpServlerResponse.sendRedirect(“path”)

28. Курс по Java, 2016

29. Курс по Java, 2016
J2EE

30. Курс по Java, 2016
Домашнее задание
Поставить Tomcat.
Сделать простое веб приложение с отправкой формы.
Посмотреть, в какой java код превращаются JSP страницы.
annie.tarasenko@7bits.it denis.nelubin@7bits.it