request payload怎么接收文件 spring

HTTP请求中，如果是get请求，那么表单参数以name=value&name1=value1的形式附到url的后面，如果是post请求，那么表单参数是在请求体中，也是以name=value&name1=value1的形式在请求体中。通过chrome的开发者工具可以看到如下（这里是可读的形式，不是真正的HTTP请求协议的请求格式）：
get请求：

[plain] view plain copy
RequestURL:
Request Method:GET
Status Code:200 OK

Request Headers
Accept:text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
Accept-Encoding:gzip,deflate,sdch
Accept-Language:zh-CN,zh;q=0.8,en;q=0.6
AlexaToolbar-ALX_NS_PH:AlexaToolbar/alxg-3.2
Connection:keep-alive
Cookie:JSESSIONID=74AC93F9F572980B6FC10474CD8EDD8D
Host:127.0.0.1:8080
Referer:
User-Agent:Mozilla/5.0 (Windows NT 6.1)AppleWebKit/537.36 (KHTML, like Gecko) Chrome/33.0.1750.149 Safari/537.36

Query String Parameters
name:mikan
address:street

Response Headers
Content-Length:2
Date:Sun, 11 May 2014 10:42:38 GMT
Server:Apache-Coyote/1.1
Post请求：

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RequestURL:
Request Method:POST
Status Code:200 OK

Request Headers
Accept:text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
Accept-Encoding:gzip,deflate,sdch
Accept-Language:zh-CN,zh;q=0.8,en;q=0.6
AlexaToolbar-ALX_NS_PH:AlexaToolbar/alxg-3.2
Cache-Control:max-age=0
Connection:keep-alive
Content-Length:25
Content-Type:application/x-www-form-urlencoded
Cookie:JSESSIONID=74AC93F9F572980B6FC10474CD8EDD8D
Host:127.0.0.1:8080
Origin:
Referer:
User-Agent:Mozilla/5.0 (Windows NT 6.1)AppleWebKit/537.36 (KHTML, like Gecko) Chrome/33.0.1750.149 Safari/537.36

Form Data
name:mikan
address:street

Response Headers
Content-Length:2
Date:Sun, 11 May 2014 11:05:33 GMT
Server:Apache-Coyote/1.1

这里要注意post请求的Content-Type为application/x-www-form-urlencoded，参数是在请求体中，即上面请求中的Form Data。
在servlet中，可以通过request.getParameter(name)的形式来获取表单参数。
而如果使用原生AJAX POST请求的话：

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function getXMLHttpRequest() {
var xhr;
if(window.ActiveXObject) {
xhr= new ActiveXObject("Microsoft.XMLHTTP");
}else if (window.XMLHttpRequest) {
xhr= new XMLHttpRequest();
}else {
xhr= null;
}
return xhr;
}

function save() {
var xhr = getXMLHttpRequest();
xhr.open("post","");
var data = "name=mikan&address=street...";
xhr.send(data);
xhr.onreadystatechange= function() {
if(xhr.readyState == 4 && xhr.status == 200) {
alert("returned:"+ xhr.responseText);
}
};
}

附上出处链接：