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ajax與mvc的配合使用（高手請進)

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ajax與mvc的配合使用（高手請進)

发表于：2007-03-04 21:31:26 楼主

我用mvc方式寫了一個登錄驗證的action，如果是執行submit數，已能正常運行.
現在我套用上ajax技術，進行異步提交數據，然後要解決的問題有以下的：
1.在actionform中，我檢驗用戶輸入的user和pass,如果為null，則actionerrors會把該錯誤對象會被actionform.add（...)保存起來，接著我要在用戶輸入的頁面上發同該錯誤並且提示，怎麽完成這些動作？由於ajax技術是不用整個頁面刷新，請各大蝦指點。。。

发表于：2007-03-04 23:44:531楼得分:0

iframe

发表于：2007-03-05 09:30:382楼得分:0

当用戶輸入了username和password后，可以用ajax将这两个值作为参数而发出请求，在服务器端处理后返回（如用out.print（）)，可以在返回串中设标志位来检查用户是否合法；更加灵活的是返回xml，这些在网上都有很多资料的，可以搜一下；用框架会挺简单，只是如果项目只会在这个地方用到ajax，那单纯的ajax已经可以满足要求^_^

发表于：2007-03-05 09:56:313楼得分:0

這裏先謝過上樓上的回複，這裏有我的源文件源碼：
jsp文件
----------------
<%@ include file= "taglib.jsp "%>
<!doctype html public "-//w3c//dtd html 4.01 transitional//en ">
<html:html locale= "true "> <html:base/>
<head>
<title> <bean:message key= "webname "/> </title>
<meta http-equiv= "pragma " content= "no-cache ">
<meta http-equiv= "cache-control " content= "no-cache ">
<meta http-equiv= "expires " content= "0 ">
<meta http-equiv= "keywords " content= "keyword1,keyword2,keyword3 ">
<meta http-equiv= "description " content= "this is my page ">
<link rel= "stylesheet " href= "_/styles.css " type= "text/css "> </link>
</head>
<script type= "text/javascript " src= "_/ajax.js "> </script>
<body>
<center> <div id= "outside " class= "outside ">
<div id= "partnerlink " class= "partnerlink " align= "right ">
<html:link page= "/ "> partner links </html:link>
<html:link page= "/ "> computer technic </html:link>
<html:link page= "/ "> my blog </html:link>
<html:link page= "/ "> online help? </html:link>
</div>
<div id= "login_search " class= "login_search ">
<div id= "logindiv " style= "text-align:left; "> <html:errors/> <html:errors/>
<html:form action= "/loginaction " method= "post " style= "width:auto;float:left; ">
userid : <html:text property= "username " styleid= "username " styleclass= "inputtxt "/>
pass: <html:password property= "password " redisplay= "true " styleid= "password " styleclass= "inputtxt "/>
<html:button property= "submit " value= "log-in " styleclass= "btncss " onclick= "ajax（ 'project/loginaction.do ', 'loginform '); "/>
</html:form>
<html:link page= "/ "> register </html:link>
<html:link page= "/ "> help? </html:link>
</div>
<div style= "text-align:right; "> </div>
</div>
</div> </center>
</body>
</html:html>

----------------
actionform
----------------
//created by myeclipse struts
// xsl source （default): platform:/plugin/com.genuitec.eclipse.cross.easystruts.eclipse_4.1.1/xslt/javaclass.xsl

package project.form;

import javax.servlet.http.httpservletrequest;

import org.apache.struts.action.actionerrors;
import org.apache.struts.action.actionmessage;
import org.apache.struts.action.actionform;
import org.apache.struts.action.actionmapping;

/**
* myeclipse struts
* creation date: 02-28-2007
*
* xdoclet definition:
* @struts.form name= "loginform "
*/
public class loginform extends actionform {

// --------------------------------------------------------- instance variables

/** password property */
private string password;

/** username property */
private string username;

// --------------------------------------------------------- methods

/**
* method validate
* @param mapping
* @param request
* @return actionerrors
*/
public actionerrors validate（
actionmapping mapping,
httpservletrequest request) {
actionerrors errors = new actionerrors（);
if（username.trim（).length（)==0){
errors.add（ "username ",new actionmessage（ "error.userid "));
}
if（password.trim（).length（)==0){
errors.add（ "password ",new actionmessage（ "error.passtx "));
}
// todo auto-generated method stub
return errors;
}

/**
* method reset
* @param mapping
* @param request
*/
public void reset（actionmapping mapping, httpservletrequest request) {

// todo auto-generated method stub
}

/**
* returns the password.
* @return string
*/
public string getpassword（) {
return password;
}

/**
* set the password.
* @param password the password to set
*/
public void setpassword（string password) {
this.password = password;
}

/**
* returns the username.
* @return string
*/
public string getusername（) {
return username;
}

/**
* set the username.
* @param username the username to set
*/
public void setusername（string username) {
this.username = username;
}

}

----------------
action
----------------
//created by myeclipse struts
// xsl source （default): platform:/plugin/com.genuitec.eclipse.cross.easystruts.eclipse_4.1.1/xslt/javaclass.xsl

package project.action;

import javax.servlet.http.httpservletrequest;
import javax.servlet.http.httpservletresponse;

import org.apache.struts.action.action;
import org.apache.struts.action.actionform;
import org.apache.struts.action.actionforward;
import org.apache.struts.action.actionmapping;

import project.form.loginform;

/**
* myeclipse struts
* creation date: 02-28-2007
*
* xdoclet definition:
* @struts.action path= "/loginaction " name= "loginform " input= "/index.jsp " scope= "request " validate= "true "
*/
public class loginaction extends action {

// --------------------------------------------------------- instance variables

// --------------------------------------------------------- methods

/**
* method ＥＸＥＣute
* @param mapping
* @param form
* @param request
* @param response
* @return actionforward
*/
public actionforward ＥＸＥＣute（
actionmapping mapping,
actionform form,
httpservletrequest request,
httpservletresponse response) {
loginform loginform = （loginform) form;
// todo auto-generated method stub
return null;
}

}

发表于：2007-03-05 09:56:514楼得分:0

----------------
ajax
----------------
/**
* ajax.js
*
* collection of scripts to allow in page communication from browser to （struts) server
* ie can reload part instead of full page
*
* how to use
* ==========
* 1) call retrieveurl from the relevant event on the html page （e.g. onclick)
* 2) pass the url to contact （e.g. struts action) and the name of the html form to post
* 3) when the server responds ...
* - the script loops through the response , looking for <span id= "name "> newcontent </span>
* - each <span> tag in the *existing* document will be replaced with newcontent
*
* note: <span id= "name "> is case sensitive. name *must* follow the first quote mark and end in a quote
* everything after the first '> ' mark until </span> is considered content.
* empty sections should be in the format <span id= "name "> </span>
*/

//global variables
var req;
var which;

/**
* get the contents of the url via an ajax call
* url - to get content from （e.g. /struts-ajax/sampleajax.do?ask=command_name_1)
* nodetooverwrite - when callback is made
* nameofformtopost - which form values will be posted up to the server as part
* of the request （can be null)
*/
function ajax（url,nameofformtopost) {

//get the （form based) params to push up as part of the get request
//url= "/ "+url+ ".do? "+getformasstring（nameofformtopost);
url= "/ "+url+ "? "+getformasstring（nameofformtopost);
alert（url);
//do the ajax call
if （window.xmlhttprequest) { // non-ie browsers
req = new xmlhttprequest（);
req.onreadystatechange = processstatechange;
try {
req.open（ "get ", url, true); //was get
} catch （e) {
alert（ "problem communicating with server\n "+e);
}
req.send（null);
} else if （window.activexobject) { // ie

req = new activexobject（ "microsoft.xmlhttp ");
if （req) {
req.onreadystatechange = processstatechange;
req.open（ "get ", url, true);
req.send（);
}
}
}

/*
* set as the callback method for when xmlhttprequest state changes
* used by retrieveurl
*/
function processstatechange（) {

if （req.readystate == 4) { // complete
alert（req.statustext);
if （req.status == 200) { // ok response
alert（req.statustext);
///alert（ "ajax response: "+req.responsetext);

//split the text response into span elements
spanelements = splittextintospan（req.responsetext);

//use these span elements to update the page
replaceexistingwithnewhtml（spanelements);

} else {
alert（ "problem with server response:\n " + req.statustext+ "\n--------------------\nreq.status= "+req.status);
}
}
}

/**
* gets the contents of the form as a url encoded string
* suitable for appending to a url
* @param formname to encode
* @return string with encoded form values , beings with &
*/
function getformasstring（formname){

//setup the return string
returnstring = " ";

//get the form values
formelements=document.forms[formname].elements;

//loop through the array , building up the url
//in the form /strutsaction.do&name=value

for （ var i=formelements.length-1; i> =0; --i ){
//we escape （encode) each value
if（formelements[i].name != "submit " && formelements[i].name != "cancel ")
returnstring=returnstring+escape（formelements[i].name)+ "= "+escape（formelements[i].value)+ "& ";
}

//return the values
return returnstring.substr（0,returnstring.length-1);
}

/**
* splits the text into <span> elements
* @param the text to be parsed
* @return array of <span> elements - this array can contain nulls
*/
function splittextintospan（texttosplit){

//split the document
returnelements=texttosplit.split（ " </span> ")

//process each of the elements
for （ var i=returnelements.length-1; i> =0; --i ){

//remove everything before the 1st span
spanpos = returnelements[i].indexof（ " <span ");

//if we find a match , take out everything before the span
if（spanpos> 0){
substring=returnelements[i].substring（spanpos);
returnelements[i]=substring;

}
}

return returnelements;
}

/*
* replace html elements in the existing （ie viewable document)
* with new elements （from the ajax requested document)
* where they have the same name and are <span> elements
* @param newtextelements （output of splittextintospan)
* in the format <span id=name> texttoupdate
*/
function replaceexistingwithnewhtml（newtextelements){

//loop through newtextelements
for （ var i=newtextelements.length-1; i> =0; --i ){

//check that this begins with <span
if（newtextelements[i].indexof（ " <span ")> -1){

//get the name - between the 1st and 2nd quote mark
startnamepos=newtextelements[i].indexof（ ' " ')+1;
endnamepos=newtextelements[i].indexof（ ' " ',startnamepos);
name=newtextelements[i].substring（startnamepos,endnamepos);

//get the content - everything after the first > mark
startcontentpos=newtextelements[i].indexof（ '> ')+1;
content=newtextelements[i].substring（startcontentpos);

//now update the existing document with this element

//check that this element exists in the document
if（document.getelementbyid（name)){

//alert（ "replacing element: "+name);
document.getelementbyid（name).innerhtml = content;
} else {
//alert（ "element: "+name+ "not found in existing document ");
}
}
}
}

---------------------------------------------------------------------------
請問我要如何在jsp的頁面上顯示actionformj裏actionerrors信息？（這裏是用了ajax提交的)

发表于：2007-03-05 10:00:405楼得分:0

可以的話加我qq：117999300,icq:237529869，大家互相交流。。。
我每天都會在線的~~

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