Auto Page Refresh Servlets with setHeader()

Auto Page Refresh Servlets with setHeader()


What is Page Refresh Servlets?

Sometimes, user requires latest information on Cricket score or latest Share prices etc. where he is required to refresh the page, say by typing F5 key. To make user’s job easier, Servlet comes with setHeader("refresh", "5") method. With this method, the same Servlet is called for every 5 seconds once and displays the latest time. This is called Page Refresh Servlets.

Let us see what API says about this method

public void setHeader(String header, String time)

Example on Page Refresh Servlets

Client file: UseRefresh.html

Servlet file: DisplayRefreshTime.java

web.xml Entry

response.setHeader("refresh", "5");

setHeader() reloads the same Servlet, DisplayRefreshtime, for each 5 seconds once and refreshes the time.

The above Servlet header is equivalent to HTMl <meta> tag.

<meta http-equiv="refresh" content="5" />

Also try with

response.setIntHeader("refresh", 5);

Here, the second parameter is an integer value (earlier it was string).

Client HTML Screen: UseRefresh.html

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Servlet screen, DisplayRefreshTime, when hyper link is clicked


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Output screen of Page Refresh Servlets

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