JavaScript请求后台数据的几种常用方式
文章目录
- 0、本博客所用到的服务器端的代码
- 1、window.location.href
- 2、window.open()
- 3、.submit()方法提交表单
- 4、.submit()方法提交表单
- 5、自定义AJAX
- 6、使用JQuery
0、本博客所用到的服务器端的代码
@WebServlet(urlPatterns = "/demoServlet")
public class DemoServlet extends HttpServlet {
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String data = request.getParameter("data");
response.getWriter().write("{'data':'"+data+"'}");
System.out.println("doPost："+data);
}
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String data = request.getParameter("data");
response.getWriter().write("{'data':'"+data+"'}");
System.out.println("doGet："+data);
}
}
1、window.location.href
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html lang="zh-cn">
<head>
<meta charset="UTF-8">
<title>JavaScript请求后台title>
<script type="text/javascript">
function fun() {
window.location.href="${pageContext.request.contextPath}/demoServlet?data=haha";
}
script>
head>
<body>
<button onclick="fun()">请求button>
body>
html>
2、window.open()
把js中的值传到后台，区别是后台请求后台之后，默认会打开新的浏览器窗口。
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html lang="zh-cn">
<head>
<meta charset="UTF-8">
<title>JavaScript请求后台title>
<script type="text/javascript">
function fun() {
// window.open("${pageContext.request.contextPath}/demoServlet?data=haha"); //打开新的窗口
window.open("${pageContext.request.contextPath}/demoServlet?data=haha","_self"); //在原窗口中撕开
}
script>
head>
<body>
<button onclick="fun()">请求button>
body>
html>
3、.submit()方法提交表单
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html lang="zh-cn">
<head>
<meta charset="UTF-8">
<title>JavaScript请求后台title>
<script type="text/javascript">
function fun() {
var form = document.forms["form1"];
form.action="${pageContext.request.contextPath}/demoServlet";
form.method="GET";
form.submit();
}
script>
head>
<body>
<form name="form1">
<input type="text" name="data">
form>
<button onclick="fun()">请求button>
body>
html>
4、.submit()方法提交表单
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html lang="zh-cn">
<head>
<meta charset="UTF-8">
<title>JavaScript请求后台title>
<script type="text/javascript">
function fun() {
var form = document.createElement("form");
//form.action="${pageContext.request.contextPath}/demoServlet?data=haha"; //这种方式不能将数据传递到后台
form.action="${pageContext.request.contextPath}/demoServlet";
var input = document.createElement("input");
input.name="data";
input.value= "haha";
form.appendChild(input);
form.method="GET";
document.body.appendChild(form);
form.submit();
}
script>
head>
<body>
<button onclick="fun()">请求button>
body>
html>
5、自定义AJAX
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html lang="zh-cn">
<head>
<meta charset="UTF-8">
<title>JavaScript请求后台title>
<script type="text/javascript">
function fun() {
var xhr;
if (window.XMLHttpRequest) {
xhr = new window.XMLHttpRequest;
} else {
xhr = new ActiveXObject("Microsoft.XMLHTTP");
}
xhr.onreadystatechange = success;
var url="${pageContext.request.contextPath}/demoServlet?data=haha";
xhr.open("POST", url, false);
xhr.send();
function success() {
if (xhr.readyState == 4 && xhr.status == 200) { //回传成功
console.info(xhr.responseText);
return true;
} else {
return false;
}
}
}
script>
head>
<body>
<button onclick="fun()">请求button>
body>
html>
6、使用JQuery
请参看博客：JQuery AJAX