「javaajax例子」java+x+
今天给各位分享javaajax例子的知识，其中也会对java+x+进行解释，如果能碰巧解决你现在面临的问题，别忘了关注本站，现在开始吧！
本文目录一览：
- 1、java ajax调用后台方法
- 2、在java Web中如何用Ajax实现用户名已存在
- 3、ajax怎么传值到后台,java的
- 4、JAVA的ajax方法？
- 5、Java的Ajax后台处理数据和返回数据代码？
- 6、ajax调用java后台的一个方法
java ajax调用后台方法
可以的，下面给你个我写的例子，验证注册时用户名的，希望对你能有所帮助
var http_request=false;
function sendRequest(method,url,content,processResponse)
{
http_request=false;
if(window.XMLHttpRequest) //mozilla
{
http_request=new XMLHttpRequest();
}else if(window.ActiveXObject) //IE
{
try
{
http_request=new ActiveXObject("Msxml2.XMLHTTP");
}catch(e)
{
http_request=new ActiveXObject("Microsoft.XMLHTTP");
}
}
if(!http_request)
{
alert("异步通信对象创建失败!");
return;
}
if(method.toLowerCase()=="get")
{
http_request.open(method,url,true);
http_request.onreadystatechange=processResponse;
http_request.send(content);
return;
}
if(method.toLowerCase()=="post")
{
http_request.open(method,url,true);
http_request.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
http_request.onreadystatechange=processResponse;
http_request.send(content);
return;
}
}
function getResult()
{
if(window.http_request.readyState==4)
{
if(window.http_request.status==200)
{
//这是返回的结果
var rText=window.http_request.responseText;
//处理结果
if(rText=="true")
{
alert("用户名称已经存在");
}else{
alert("用户名称可以使用");
}
}
}
}
//调用
sendRequest("POST","user.do","userName="+name,getResult);
看不懂或者有问题了可以百度Hi
在java Web中如何用Ajax实现用户名已存在
我给你做一个例子：希望能帮到你。
实现的功能：注册页面上当输入逗lixin地时，显示该用户已被注册。其他的名称无所谓。希望能帮到你。欢迎追问。
一个简单的jsp页面：
%@ page language="java" import="java.util.*" pageEncoding="utf-8"%
%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%
!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
html
head
base href="%=basePath%"
titleMy JSP 'index.jsp' starting page/title
!--
link rel="stylesheet" type="text/css" href="styles.css"
--
script type="text/javascript" language="javascript"
//根据浏览器的不同创建不同的XMLHttpRequest
function createXmlHttpRequest(){
var xmlreq=false;
if(window.XMLHttpRequest){
xmlreq=new XMLHttpRequest();
}else if(window.ActiveXobject){
try{
xmlreq = new ActiveXobject("Msxm12.XMLHTTP");
}catch(e1){
try{
xmlreq = new ActiveXobject("Miscoft.XMLHTTP");
}catch(e2){
}
}
}
return xmlreq;
}
//
function usernameCheck(){
var username = document.all.username.value;//获得text的值
var request = createXmlHttpRequest();//创建request的对象
request.open("post","servlet/ValidationServlet?username="+username);
request.send();
request.onreadystatechange = function(){
if(request.readyState==4request.status==200)
{
var value = request.responseText;
if(value=="true"){
document.all.unc.innerHTML="该用户名已经被注册";}
}else{
document.all.unc.innerHTML="该用户可以注册";
}
}}
/script
/head
body
用户姓名：input type ="text" name="username" onblur="usernameCheck()" /font color="red" size="-1" id="unc"/font
br
用户密码：input type ="password" name= "userpw" /
/body
/html
用到的Servlet：
package sample;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class ValidationServlet extends HttpServlet {
/**
* The doGet method of the servlet. br
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
this.doPost(request, response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html");
String username = request.getParameter("username");
if(username.equals("lixin")){
response.getWriter().print("true");}
else{
response.getWriter().print("false");
}
}
}
ajax怎么传值到后台,java的
给你个例子，用得servlet，你可以改改
index.html
html
head
title第1个ajax例子/title
script type="text/javascript"
var xmlHttp;//局部刷新的关键，通过这个对象与服务器连接
//将xmlHttp实例化
function init()
{
try{
xmlHttp= new ActiveXObject('Msxml2.XMLHTTP');
}
catch(e)
{
try{
xmlHttp= new ActiveXObject('Microsoft.XMLHTTP');
}
catch(e)
{
try{
xmlHttp= new XMLHttpRequest();
}catch(e){}
}
}
}
//调用此方法与服务器互动
function ajax(name)
{
init();
if(name.length==0)
{
document.getElementById("divname").innerHTML="必须输入用户名";
document.getElementById("name").focus();
return;
}
var url="ajax?name="+name+"date="+Date();//向servlet传递参数
xmlHttp.open("get",url,true);//向servlet传递参数，设置传递模式和url
xmlHttp.onreadystatechange=handleCheckName;//设置回调方法为handleCheckName
xmlHttp.send(null);
}
function handleCheckName()
{
if(xmlHttp.readyState==4)
{
if(xmlHttp.status==200)
{
if(xmlHttp.responseText=="1") //xmlHttp.responseText为服务器返回的数据
{
document.getElementById("divname").innerHTML="对不起,用户已存在!";
document.getElementById("divname").style.color="black";
}
if(xmlHttp.responseText=="2")
{
document.getElementById("divname").innerHTML="用户名只能是3-10位字母,数字";
document.getElementById("divname").style.color="black";
}
if(xmlHttp.responseText=="3")
{
document.getElementById("divname").innerHTML="恭喜你,用户名可以继续注册!";
document.getElementById("divname").style.color="red";
}
}
}
}
/script
/head
body
input type="text" name="name" onkeyup="ajax(this.value);" /
div id="divname"/div
/body
/html
web.xml
?xml version="1.0" encoding="ISO-8859-1" ?
web-app
servlet
servlet-nameReturnName/servlet-name
servlet-classajax.servlet.ReturnName/servlet-class
/servlet
servlet-mapping
servlet-nameReturnName/servlet-name
url-pattern/ajax/url-pattern
/servlet-mapping
/web-app
ReturnName.java
package ajax.servlet;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class ReturnName extends HttpServlet{
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String name=request.getParameter("name");
int a=0;
if(name.equals("asdasd")){
a=1;
}else if(!name.matches("[a-zA-Z0-9]{3,10}")){
a=2;
}else{
a=3;
}
response.getWriter().print(a);
}
public void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
doGet(req,resp);
}
}
JAVA的ajax方法？
//方式一:使用post请求的方式,不通过url传参,采用data传参
$.ajax({
url:"userAction_findMangerByDeptId",//访问的地址
type:"post",
data:{"传递到后台的参数名":参数},
dataType:'text',//后台返回的数据格式类型
success:function(data){
})
}
})
}
//方式二:这是get提交方法,会出现中文乱码,所以要 1.先将数据转码
参数名 = encodeURI(encodeURI(要转的参数));
$.ajax({
url:"userAction_findMangerByDeptId?参数名"+参数值,
type:"get",
dataType:'text',//后台返回的数据格式类型
success:function(data){
})
}
})
}
2.后台接收前端传递内容后要进行解码
String 参数名 = URLDecoder.decode(接收的参数);
Java的Ajax后台处理数据和返回数据代码？
1新建一个servlet xml中相应配置(一般自动)
2创建service方法
3接受参数，做操作，返回数据
比如页面发送ajax请求到SomeServlet
$.post("SomeServlet的请求路径",{param:"param"},function(data){ //data为返回的e799bee5baa6e997aee7ad94e58685e5aeb931333337613931数据以json形式 alert(data.id + " " + data.name + " " + data.age );},"json");
Servlet
public void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("utf-8"); response.setContentType("text/html;charset=utf-8"); PrintWriter out = response.getWriter(); String param = request.getParameter("param");//获取参数 //你的操作 //返回数据 String json = "{\"id\":1,\"name\":\"张三\",\"age\":18}"; out.print(json);}
ajax调用java后台的一个方法
ajax调用java后台的方法，其实是通过url链接来访问，示例如下：
package com.xxxx.xxxx.servlet;
import java.io.IOException;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.sql.DataSource;
public class oaLoginLimitedServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
private static Connection conn=null;
private static PreparedStatement pstmt=null;
public oaLoginLimitedServlet() {
super();
}
public void destroy() {
super.destroy();
}
public static String getCount(String userid)
{
String v_sql=".....";
String v_count="";
try {
pstmt = conn.prepareStatement(v_sql);
pstmt.setString(1, userid);
ResultSet rs = pstmt.executeQuery();
while(rs.next()){
v_count = rs.getString(1);
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally{
try {
pstmt.close();
conn.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
return v_count;
}
public static Connection getConnection(){
Context ctx = null;
try {
ctx = new InitialContext();
DataSource ds = (DataSource)ctx.lookup("jndiname");
conn = ds.getConnection();
} catch (Exception e) {
e.printStackTrace();
}
return conn;
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String v_userid=request.getParameter("userid");
System.out.println(v_userid);
getConnection();
String v_count=getCount(v_userid);
response.setCharacterEncoding("UTF-8");
response.getWriter().write(v_count);
response.flushBuffer();
}
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request,response);
}
}
如果要前端能够访问到该servlet，需要将该servlet注册到 web.xml文件中。需要在web.xml文件中添加以下内容
[html] view plaincopy
servlet
servlet-nameoaLoginLimitedServlet/servlet-name
servlet-classcom.xxxx.xxxx.servlet.oaLoginLimitedServlet/servlet-class
/servlet
servlet-mapping
servlet-nameoaLoginLimitedServlet/servlet-name
url-pattern/oaLoginLimitedServlet/url-pattern
/servlet-mapping
重启相关服务。
通过ajax就可以调用了。
[html] view plaincopy
var msg = $.ajax({
type: "post",
url: ....+'/oaLoginLimitedServlet?userid='+ $('#act').val(),
async:false
}).responseText;
javaajax例子的介绍就聊到这里吧，感谢你花时间阅读本站内容，更多关于java+x+、javaajax例子的信息别忘了在本站进行查找喔。