WML Development Detailed Guide

WAP Development Getting Started - Building a development environment tells how to build a development environment of WAP applications, which will mainly introduce WML related knowledge, how to develop WAP applications.

WML is a XML-based tag language, and her official description and specification is maintained by the WAP forum. The WML document type is defined as an XML file type, http://www.wapforum.org/dtd/wml_1.1.xml. Like the HTML language, WML is to display data, while the purpose of XML is to describe data, we define a series of tags and organize to become a syntax specification to call it DTD (Document Type Definition). The WAP browser is installed in the mobile phone that he can resolve these tags and display it correctly on the phone screen.

Usually in the beginning of WML text, there is such a content We call it preambularly. The following is tagged, all our data is nesting in these two tags. WML is very small, basic can be divided into two kinds known as deck / cards called Event. Here, you can't tell it here. When we develop WML applications, you can provide you with an online reference: Online WML Tag Reference. In the tag We call it a decker, each screen, we define it as a CARD, because WML is defined for wireless network transmission, we can allow for a limit of bandwidth, we allow In a DECK contains multiple cars and can be downloaded to the user agent together so that we can switch between different screens locally, avoiding access every time. Of course, this also adds a burden to the client, so we have to avoid excessive CARDs in Deck.

Below we write a WML example test.wml, the content is as follows:

UserName: john doe Paul Smith joe dean bill Todd

password:

You Entered: Name: $ (Name) Password: $ (Password) In this deck, three cars contains three CARDs, can be downloaded to the client, and we can switch between different CARDs by pressing the button, you can take a look in the mobile phone or WinWap emulator. Run the effect. Below is the run screenshot under WinWap.

Although we can develop WML applications, these are all static contents after all. What if we want to develop and interact with the server? The answer is of course we can use servlet technology. Look at the example below:

books < Option value = "music"> music video Software You can select Item from the list. After transferring to the server over a wireless network, servlet gets the user's selection and sends it to the user, servlet The code is as follows: package com.j2medev.mingjava; import java.io.ioException; import java.io.printwriter;

Import javax.servlet.ServletException; import javax.servlet.http.httpservlet; import javax.servlet.http.httpservletRequest; import javax.servlet.http.httpservletResponse;

Public class wapservlet extends httpservlet {

protected void doGet (HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {String select = request.getParameter ( "Items"); response.setContentType ( "text / vnd.wap.wml"); PrintWriter out = response.getWriter () Out.println (""); Out.println (""); out.println (""); out.println (" "); out.println ("

"); out.println (" You SELECTED " SELECT); OUT.PRINTLN (" ") Out.println (""); out.println ("");}

protected void doPost (HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {doGet (request, response);}} Servlet and correct deployment wml file, is confirmed when the input http://222.28.218.222:8088/test2.wml winwap You can see your selected xxxx content.

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