Javaweb获取表单数据的多种方式
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(Stringname)：通过key，返回一个value。
getParameterValues(Stringname)：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"})
publicclassFormServletextendsHttpServlet{
privatestaticfinallongserialVersionUID=1L;
publicFormServlet(){
super();
}
protectedvoiddoGet(HttpServletRequestrequest,HttpServletResponseresponse)throwsServletException,IOException{
response.setContentType("text/json;charset=utf-8");
PrintWriterout=response.getWriter();
Enumeration<String>paramNames=request.getParameterNames();
while(paramNames.hasMoreElements()){
Stringname=paramNames.nextElement();
String[]values=request.getParameterValues(name);
if(values!=null&&values.length>0){
StringBuilderbuilder=newStringBuilder();
for(inti=0;i<values.length;i++){
builder.append(values[i]+"");
}
out.println(name+":"+builder.toString());
}
}
}
protectedvoiddoPost(HttpServletRequestrequest,HttpServletResponseresponse)throwsServletException,IOException{
doGet(request,response);
}
}
form表单：
<!DOCTYPEhtml> <html> <head> <metacharset="UTF-8"> <title>Inserttitlehere</title> </head> <body> <formaction="/TomcatDemo/form"method="post"> 用户名<inputtype="text"name="username"/><br/> 密码<inputtype="password"name="password"/><br/> 性别<inputtype="radio"name="sex"value="male"checked="checked"/>男 <inputtype="radio"name="sex"value="female"/>女<br/> 爱好<inputtype="checkbox"name="hobby"value="basketball"/>篮球 <inputtype="checkbox"name="hobby"value="football"/>足球 <inputtype="checkbox"name="hobby"value="game"/>游戏 <inputtype="checkbox"name="hobby"value="media"/>电影<br/> 城市<selectname="city"> <optionvalue="bj">北京</option> <optionvalue="sh">上海</option> <optionvalue="sz">深圳</option> <optionvalue="hz">杭州</option> </select><br/> <inputtype="submit"value="注册"/> <inputtype="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"})
publicclassFormServletextendsHttpServlet{
privatestaticfinallongserialVersionUID=1L;
publicFormServlet(){
super();
}
protectedvoiddoGet(HttpServletRequestrequest,HttpServletResponseresponse)throwsServletException,IOException{
response.setContentType("text/json;charset=utf-8");
PrintWriterout=response.getWriter();
Useruser=newUser();
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()){
Stringname=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
PropertyDescriptorpd=null;
try{
pd=newPropertyDescriptor(name,User.class);
}catch(IntrospectionExceptione){
e.printStackTrace();
}
if(values!=null&&pd!=null){
Methodsetter=pd.getWriteMethod();
try{
if(values.length==1){
setter.invoke(user,values[0]);
}else{
setter.invoke(user,(Object)values);
}
}catch(IllegalAccessExceptione){
e.printStackTrace();
}catch(IllegalArgumentExceptione){
e.printStackTrace();
}catch(InvocationTargetExceptione){
e.printStackTrace();
}
}
}
out.println("获取表单数据之后："+user.toString());
}
protectedvoiddoPost(HttpServletRequestrequest,HttpServletResponseresponse)throwsServletException,IOException{
doGet(request,response);
}
}
PropertyDescriptor的使用，点击查看
User类
publicclassUser{
privateStringusername;//属性名称需要和表单数据中的name值保持一致
privateStringpassword;
privateStringsex;
privateString[]hobby;
privateStringcity;
...
//setget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"})
publicclassFormServletextendsHttpServlet{
privatestaticfinallongserialVersionUID=1L;
publicFormServlet(){
super();
}
protectedvoiddoGet(HttpServletRequestrequest,HttpServletResponseresponse)throwsServletException,IOException{
response.setContentType("text/json;charset=utf-8");
PrintWriterout=response.getWriter();
Useruser=newUser();
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(IllegalAccessExceptione){
e.printStackTrace();
}catch(InvocationTargetExceptione){
e.printStackTrace();
}
out.println("获取表单数据之后："+user.toString());
}
protectedvoiddoPost(HttpServletRequestrequest,HttpServletResponseresponse)throwsServletException,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毛票票。