Introduction to ServletResponse
Servlet API provides two important interfaces ServletResponse and HttpServletResponse to assist in sending response to client.
Some Important Methods of ServletResponse
| Methods | Description |
|---|
PrintWriter getWriter() | returns a PrintWriter object that can send character text to the client. |
void setBufferSize(int size) | Sets the preferred buffer size for the body of the response |
void setContentLength(int len) | Sets the length of the content body in the response In HTTP servlets, this method sets the HTTP Content-Length header |
void setContentType(String type) | sets the content type of the response being sent to the client before sending the respond. |
void setBufferSize(int size) | sets the preferred buffer size for the body of the response. |
boolean isCommitted() | returns a boolean indicating if the response has been committed |
void setLocale(Locale loc) | sets the locale of the response, if the response has not been committed yet. |
HttpServletResponse Interface
HttpServletResponse interface adds the methods that relate to the HTTP response. It extends the ServletResponse interface. The object of HttpServletResponse is created in servlet container.
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Some Important Methods of HttpServletResponse
| Methods | Description |
|---|
void addCookie(Cookie cookie) | adds the specified cookie to the response. |
void sendRedirect(String location) | Sends a temporary redirect response to the client using the specified redirect location URL and clears the buffer |
int getStatus() | gets the current status code of this response |
String getHeader(String name) | gets the value of the response header with the given name. |
void setHeader(String name, String value) | sets a response header with the given name and value |
void setStatus(int sc) | sets the status code for this response |
void sendError(int sc, String msg) | sends an error response to the client using the specified status and clears the buffer |
Example of HttpServletResponse interface on Eclipse
For creating a HttpServletResponse interface below is the directory structure of the program:
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Following are the steps for creating the program.
Step 1: Create a dynamic project on eclipse by clicking on File => New => Dynamic Web Project
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Step 2: Now create an HTML file.
Right-click on the project and then click on HTML file. Give the name of the file and then click on the finish button.
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And write the below code.
<!DOCTYPE html>
<html>
<head>
<meta charset="ISO-8859-1">
<title>studytonight.com</title>
</head>
<body>
<form align="center" action="display" method="get">
<h3>studytonight.com</h3>
<hr>
Enter User name: <input type="text" name="val1"><br><br>
Enter Password: <input type="password" name="val2" ><br><br>
<input type="submit" value="login">
</body>
</html>
Step 3: now add the below code in web.xml file.
web.xml file is a deployment descripter. Here we have all the configurations.
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd" id="WebApp_ID" version="4.0">
<display-name>ServletResponse</display-name>
<servlet>
<servlet-name>abc3</servlet-name>
<servlet-class>demo4</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>abc3</servlet-name>
<url-pattern>/display</url-pattern>
</servlet-mapping>
</web-app>
Step 4: Now next create a servlet. For this create a class. Give the package name and the class name.
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Add the below code in the class file.
Demo4.java
import javax.servlet.http.*;
import javax.servlet.*;
import java.io.*;
public class demo4 extends HttpServlet{
public void doGet(HttpServletRequest req,HttpServletResponse res)
throws ServletException,IOException
{
res.setContentType("text/html");
PrintWriter pwriter=res.getWriter();
String uname=req.getParameter("val1");
String pw=req.getParameter("val2");
pwriter.println("User Details Page:");
pwriter.println("Hello "+uname);
pwriter.println("Your Password is **"+pw+"**");
pwriter.close();
}
}
Now, Run the code
To run the code, right-click on the project and select Run As => Run on Server.
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Below is the demo4.html page. Fill all the fields and click on the login button for landing in the servlet page.
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This is the servlet page.
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