Java servlet:通过servlet中的ajax获取空参数
当我在servlet中获取参数时,我会将我的值设置为“null” 我做错了什么 这就是我设置参数的方式 从使用脚本标记的jsp页面Java servlet:通过servlet中的ajax获取空参数,java,javascript,ajax,jsp,servlets,Java,Javascript,Ajax,Jsp,Servlets,当我在servlet中获取参数时,我会将我的值设置为“null” 我做错了什么 这就是我设置参数的方式 从使用脚本标记的jsp页面 String isno1=request.getParameter("isbn"); String bktitle2=request.getParameter("booktitle"); String authr3=(String) request.getParameter("author"); System.out.
String isno1=request.getParameter("isbn");
String bktitle2=request.getParameter("booktitle");
String authr3=(String) request.getParameter("author");
System.out.println(isno1+bktitle2+authr3);
Enumeration paramaterNames = request.getParameterNames();
函数getHTTPObject()
{
var-httpobject;
如果(!httpobject&&typeof(XMLHttpRequest)!='undefined')
{
试一试{
httpobject=新的XMLHttpRequest();
}
捕获(e){
xmlhttp=false;
}
}
返回httpobject;
}
var httpob=getHTTPObject();
函数handleHttpResponse(){
if(httpob.readyState==4){
//警报(“sd”);
var结果=httpob.responseText;
警报(结果);
/*文件。写下(“嗨,你的书已经提交了!!!”*/
}
}
函数auth(){
var params=“isbn=“+document.mayurform.isbn.value+”&booktitle=“+document.mayurform.booktitle.value+”&author=“+document.mayurform.author.value;
警报(“参数发送”+参数);
httpob.open(“POST”,“addbook”,true);
setRequestHeader(“内容类型”,“应用程序/x-www-form-urlencoded”);
httpob.setRequestHeader(“内容长度”,参数长度);
setRequestHeader(“连接”,“关闭”);
/*setRequestHeader(“内容类型”,“应用程序/x-www-from-urlencoded”);
httpob.setRequestHeader(“内容长度”,参数长度);
setRequestHeader(“连接”,“关闭”)*/
httpob.onreadystatechange=handleHttpResponse;
httpob.send();
}
这是我的表格
<script type="text/javascript">
function getHTTPObject()
{
var httpobject;
if(!httpobject && typeof(XMLHttpRequest) != 'undefined')
{
try{
httpobject=new XMLHttpRequest();
}
catch(e){
xmlhttp=false;
}
}
return httpobject;
}
var httpob=getHTTPObject();
function handleHttpResponse(){
if(httpob.readyState==4){
//alert("sd");
var result=httpob.responseText;
alert(result);
/* document.write("hi your book is submitted !!!!!"); */
}
}
function auth(){
var params="isbn="+document.mayurform.isbn.value+"&booktitle="+document.mayurform.booktitle.value+"&author="+document.mayurform.author.value;
alert("params sending"+params);
httpob.open("POST","addbook",true);
httpob.setRequestHeader("Content-type","application/x-www-form-urlencoded");
httpob.setRequestHeader("Content-length",params.length);
httpob.setRequestHeader("Connection","close");
/* httpob.setRequestHeader("Content-type","application/x-www-from-urlencoded");
httpob.setRequestHeader("Content-length",params.length);
httpob.setRequestHeader("Connection","close"); */
httpob.onreadystatechange=handleHttpResponse;
httpob.send();
}
</script>
国际书号。
书名
作者
您正在获取ID为的参数,您应该给出名称
比如说
字符串isno1=request.getParameter(“isbn”)//这是isbn是id
你应该写
<form style="margin: 100px;" name="mayurform">
<table align="center">
<tr>
<td align="center">ISBN NO.</td>
<td><input align="middle" type="text" size="20" name="id" id="isbn">
</tr>
<tr>
<td align="center">Book-Title</td>
<td><input align="middle" type="text" size="20" name="pwd" id="booktitle">
</td>
</tr>
<tr>
<td align="center">Author</td>
<td><input align="middle" type="text" size="20" name="pwd" id="author">
</tr>
<tr>
<td><input align="middle" type="button" size="20" name="Add-Book" onclick="auth()">
</tr>
</table>
</form>
字符串isno1=request.getParameter(“id”)-----------^
而且
<input align="middle" type="text" size="20" name="id" id="isbn">
String isno1=request.getParameter("id");-----------^
两个输入具有相同的**名称**
请检查
使用下面的ajax
send()
发送数据
<td><input align="middle" type="text" size="20" name="pwd" id="booktitle">
<td><input align="middle" type="text" size="20" name="pwd" id="author">
调用
httpob.send()
,传入将要发送的参数(不带“?”前缀)。@MayurGupta表单中有很多更改。为所有输入类型选择不同的Id和名称
function auth(){
var params="isbn="+document.mayurform.isbn.value+"&booktitle="+document.mayurform.booktitle.value+"&author="+document.mayurform.author.value;
alert("params sending"+params);
.......
...
httpob.send(params);//change is here
}