Javaweb获取表单数据的多种方式

时间:2017-06-02 23:41 来源:武松娱乐整理 字体:[ ] 评论:
Javaweb获取表单数据的几种方式 一、通过键值对的形式获取表单数据 getParameter(String name):通过key,返回一个value。
getParameterValues(String name):通过key返回一个string数组(多个值)
getParameterNames():返回form表单中的所有key值。
下面介绍通过键值对获取form表单数据的数据的方法:
@WebServlet({ "/FormServlet", "/form" }) public class FormServlet extends HttpServlet { private static final long serialVersionUID = 1L; public FormServlet() { super(); } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/json;charset=utf-8"); PrintWriter out = response.getWriter(); Enumeration<String> paramNames = request.getParameterNames(); while (paramNames.hasMoreElements()) { String name = paramNames.nextElement(); String[] values = request.getParameterValues(name); if(values!=null && values.length>0){ StringBuilder builder = new StringBuilder(); for (int i = 0; i < values.length; i++) { builder.append(values[i]+" "); } out.println(name+" : "+builder.toString()); } } } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } }
form表单:
<!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>Insert title here</title> </head> <body> <form action="/TomcatDemo/form" method="post"> 用户名<input type="text" name="username"/><br/> 密码 <input type="password" name="password"/><br/> 性别 <input type="radio" name="sex" value="male" checked="checked"/>男 <input type="radio" name="sex" value="female"/>女<br/> 爱好 <input type="checkbox" name="hobby" value="basketball"/>篮球 <input type="checkbox" name="hobby" value="football"/>足球 <input type="checkbox" name="hobby" value="game"/>游戏 <input type="checkbox" name="hobby" value="media"/>电影<br/> 城市 <select name="city"> <option value="bj">北京</option> <option value="sh">上海</option> <option value="sz">深圳</option> <option value="hz">杭州</option> </select><br/> <input type="submit" value="注册"/> <input type="submit" value="登入"/><br/> </form> </body> </html>
二、通过Map的形式获取表单数据 getParameterMap():获取form表单的数据,以map的格式封装起来
示例:
@WebServlet({ "/FormServlet", "/form" }) public class FormServlet extends HttpServlet { private static final long serialVersionUID = 1L; public FormServlet() { super(); } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/json;charset=utf-8"); PrintWriter out = response.getWriter(); User user = new User(); out.println("获取表单数据之前:"+user.toString()); Map<String,String[]> map = request.getParameterMap(); for (Map.Entry<String, String[]> m : map.entrySet()) { String name = m.getKey(); String[] values = m.getValue(); //属性描述器:表示JavaBean类通过存储器导出一个属性 PropertyDescriptor pd=null; try { pd = new PropertyDescriptor(name, User.class); } catch (IntrospectionException e) { e.printStackTrace(); } if (values!=null&& pd !=null) { Method setter = pd.getWriteMethod(); try { if (values.length==1) { setter.invoke(user, values[0]); }else { setter.invoke(user, (Object)values); } } catch (IllegalAccessException e) { e.printStackTrace(); } catch (IllegalArgumentException e) { e.printStackTrace(); } catch (InvocationTargetException e) { e.printStackTrace(); } } } out.println("获取表单数据之后:"+user.toString()); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } }
PropertyDescriptor的使用,点击查看 User类
public class User { private String username;//属性名称需要和表单数据中的name值保持一致 private String password; private String sex; private String[] hobby; private String city; ... //set get方法省略 }
三、通过第三方jar包获取封装表单数据 使用第三方jar包:commons-beanutils-1.8.3.jar
@WebServlet({ "/FormServlet", "/form" }) public class FormServlet extends HttpServlet { private static final long serialVersionUID = 1L; public FormServlet() { super(); } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/json;charset=utf-8"); PrintWriter out = response.getWriter(); User user = new User(); out.println("获取表单数据之前:"+user.toString()); try { //通过第三方jar包处理 BeanUtils.populate(user, request.getParameterMap()); } catch (IllegalAccessException e) { e.printStackTrace(); } catch (InvocationTargetException e) { e.printStackTrace(); } out.println("获取表单数据之后:"+user.toString()); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } }
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持武松娱乐。
顶一下(0) 踩一下(0)
Top_arrow
武松娱乐注册