Java Servlet API Development Introduction
Java Servlet API Development Introduction
Java Servlet is a Java program running on the web server that can process requests from the web browser and generate a dynamic web page.Using Java Servlet API, developers can easily create scalable, high -performance web applications.
This article will lead you to the development and entry of the Java Servlet API, including how to set up a development environment, write and deploy Servlet, and how to deal with requests and generate responses.
1. Set the development environment
First, install the Java Development Kit (JDK) and any commonly used integrated development environment (IDE), such as Eclipse or Intellij IDEA.Make sure your development environment is correctly configured and link to JDK.
2. Create a new Servlet project
Create a new Servlet project in IDE.Generally, IDE will automatically generate a basic service template, which contains a Java class that inherits from javax.servlet.httpServlet.
3. Write the service code
Open the generated Servlet class and implement Doget and Dopost methods.These methods will process Get and POST requests from the web browser.
Below is a simple Servlet example. It accepts a parameter named "name" and generates HTML response containing the parameter:
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
@WebServlet("/hello")
public class HelloServlet extends HttpServlet {
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String name = request.getParameter("name");
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
out.println("<html>");
out.println("<head><title>Hello Servlet</title></head>");
out.println("<body>");
out.println("<h1>Hello, " + name + "!</h1>");
out.println("</body></html>");
}
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}
4. Deploy Servlet
Deploy the written Servlet into the web server.In the IDE, you can run your service directly on the embedded Web server, or deploy the service war file to the independent web server.
5. Test service
Use a web browser to visit your service.According to the above example, if you pass the parameter "name" in the URL, it will display "Hello, name!" On the page.
Summarize:
This article introduces the basic knowledge and development steps of Java Servlet API.From setting the development environment to the writing and deployment of the service, to the processing request and generating response, you should now be able to start using the Java Servlet API to develop a dynamic web application.
Please note that this article only involves the primary concept and entry content of Java Service.To understand the advanced characteristics and more complicated usage of the Java Servlet API, please refer to the official documents and other related resources.
