本文主要是介绍HttpServlet 简单表单示例，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！
本文代码转载自《Servlet、JSP和Spring MVC初学指南》
下面是一个简单的利用get进行输入表单页面显示，post进行 表单提交内容展示的实例
package main.ServletTest;/*** Created by ehang on 2017/2/8.*/import java.io.IOException;
import java.io.PrintWriter;
import java.util.Enumeration;
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(name = "FormServlet",urlPatterns = {"/form"}
)
public class FormServlet extends HttpServlet {private static final long serialVersionUID = 54L;private static final String TITLE = "Order Form";@Overridepublic void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException{response.setContentType("text/html");PrintWriter writer = response.getWriter();writer.println("<html><head><title>" +TITLE +"</title></head><body>" +"<h1>" + TITLE + "</h1>" +"<form method = 'post'>"+ "<table>"+ "<tr>"+ "<td>Name:</td>"+ "<td><input name = 'name'/></td>"+ "</tr>"+ "<tr>"+ "<td>Address:</td>"+ "<td><textarea name = 'address' cols = '40' rows = '5'></textarea></td>"+ "</tr>"+ "<tr>"+ "<td>Country:</td>"+ "<td><select name = 'country'>"+ "<option>United States</option>"+ "<option>Canada</option>"+ "</select></td>"+ "</tr>"+ "<tr>"+ "<td>Delivery Method</td>"+ "<td><input type = 'radio' name = 'deliveryMethod' value = 'First Class'/>First Class"+ "<input type = 'radio' name = 'deliveryMethod' value = 'Second Class'/>Second Class"+ "</td>"+ "</tr>"+ "<tr>"+ "<td>Shipping Instructions:</td>"+ "<td><textarea name = 'instruction' cols = '40' rows = '5'></textarea>"+ "</td>"+ "</tr>"+ "<tr>"+ "<td> </td>"+ "<td><textarea name = 'instructiuon' cols = '40' rows = '5'></textarea></td>"+ "</tr>"+ "<tr>"+ "<td>Please send me the latest product catalog</td>"+ "<td><input type = 'checkbox' name = 'catalogRequest'></td>"+ "</tr>"+ "<tr>"+ "<td> </td>"+ "<td><input type = 'reset'/><input type = 'submit'></td>"+ "</tr>"+ "</table>"+ "</form>" +"</body></html>");}@Overridepublic void doPost(HttpServletRequest request, HttpServletResponse response )throws ServletException, IOException{response.setContentType("text/html");PrintWriter writer = response.getWriter();writer.println("<html>" +"<head><title>" +TITLE +"</title></head><body>" +"<h1>" +TITLE +"</h1>" +"<table>" +"<tr>" +"<td>Name:</td>" +"<td>" +request.getParameter("name") +"</td>" +"</tr>" +"<tr>" +"<td>Address:</td>" +"<td>" +request.getParameter("address") +"</td>" +"</tr>" +"<tr>" +"<td>Country:</td>" +"<td>" +request.getParameter("country") +"</td>" +"</tr>" +"<tr>" +"<td>Shipping Instructions:</td>" +"<td>");String[] instructions = request.getParameterValues("instructions");if(instructions != null){for(String instruction: instructions){writer.println(instruction + "<br/>");}}writer.println("</td></tr>" +"<tr><td>Delivery Method:</td>" +"<td>" +request.getParameter("deliveryMethod") +"</td></tr>" +"<tr>" +"<td>Catalog Request:</td>" +"<td>");if(request.getParameter("catalogRequest") == null){writer.println("No");}else{writer.println("Yes");}writer.println( "</td></tr>" +"</table>");writer.println("<div style = 'border:1px soild #ddd; margin-top:40px;font-size:90%'>" +"Debug Info<br/>");Enumeration<String> parameterNames = request.getParameterNames();while(parameterNames.hasMoreElements()){String paramName = parameterNames.nextElement();writer.println(paramName + ": ");String[] paramValues = request.getParameterValues(paramName);for(String paramValue: paramValues){writer.println(paramValue + "<br/>");}}writer.println("</div></body>" +"</html>");}}使用input标签对应的name来通过request.getParameter得到提交值。该例使用 annotation WebServlet urlPatterns映射，一般提到的映射方式为web.xml中的部署描述符配置方式。 后者较前者的优势在于提供了WebServlet所不支持的若干描述 如位于<servlet>中可配置<load-on-startup> 该节点支持整数值作为输入，指定在程序启动时而非第一次调用时初始化servlet类， 当对多个servlet都配置了该节点时，不同的load-on-start节点值决定了载入的先后顺序， 基本上类似于对中间件指定载入顺序。 描述符配置的方式也可包含如servlet进行初始化信息。如利用annotation WebServlet可如下指定servlet初始化参数
@WebServlet(name = "test",urlpatterns = {"/test"};initParams = {@WebInitParams(name = "admin", value = "SV")}
)相应的部署描述符servlet配置为
<servlet><servlet-name>test</servlet-name><servlet-class>SomeClass</servlet-class><init-param><param-name>admin</param-name><param-value>SV</param-value></init-param>
</sertvlet><servlet-mapping><servlet-name>test</servlet-name><url-pattern>/test</url-pattern>
</servlet-mapping>这篇关于HttpServlet 简单表单示例的文章就介绍到这儿，希望我们推荐的文章对编程师们有所帮助！
