ajax参数传递与后台接收

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ajax参数传递与后台接收

Servlet中读取http参数的方法

• Enumeration getParameterNames() 返回一个 String 对象的枚举，包含在该请求中包含的参数的名称
• String getParameter(String name) 以字符串形式返回请求参数的值，或者如果参数不存在则返回 null。
• String getQueryString() 返回包含在路径后的请求 URL 中的查询字符串。
• String[] getParameterValues(String name) 返回一个字符串对象的数组，包含所有给定的请求参数的值，如果参数不存在则返回 null。
• ServletInputStream getInputStream() 使用 ServletInputStream，以二进制数据形式检索请求的主体。

ajax默认contentType为application/x-www-form-urlencoded

使用默认contentType，参数追加到url后传递

$.ajax({
url: "http://localhost:8082/boot/request/parameter?name=aaa&paraB=bbb",
contentType: "application/x-www-form-urlencoded;charset=utf-8",
success: function(json){
console.log(json);
}
});


//请求中包含的参数的名称
Enumeration<String> parameterNames = request.getParameterNames();
while (parameterNames.hasMoreElements()) {
String s = parameterNames.nextElement();
System.out.println("getParameterNames:" + s);
String paraA = request.getParameter(s);
System.out.println("getParameter:" + paraA);
}// 返回包含在路径后的请求 URL 中的查询字符串
String queryString = request.getQueryString();
System.out.println("getQueryString:" + queryString);


使用默认contentType，参数放到data中传递

$.ajax({
url: "http://localhost:8082/boot/request/parameter",
contentType: "application/x-www-form-urlencoded;charset=utf-8",
data: {name: "aaa", paraB:"bbb"},
success: function(json){
console.log(json);
}
});


//请求中包含的参数的名称
Enumeration<String> parameterNames = request.getParameterNames();
while (parameterNames.hasMoreElements()) {
String s = parameterNames.nextElement();
System.out.println("getParameterNames:" + s);
String paraA = request.getParameter(s);
System.out.println("getParameter:" + paraA);
}


使用默认contentType，data中传递数组

$.ajax({
url: "http://localhost:8082/boot/request/parameter",
type: "post",
contentType: "application/x-www-form-urlencoded;charset=utf-8",
data: {foo: ["bar1", "bar2"]},
success: function (json) {
console.log(json);
}
});


// 返回一个字符串对象的数组
String[] parameterValues = request.getParameterValues("foo[]");
if (parameterValues != null) {
for (String parameterValue : parameterValues) {
System.out.println("getParameterValues:" + parameterValue);
}
}


使用contentType为application/json，在data中传递复杂参数

$.ajax({
url: "http://localhost:8082/boot/request/parameter",
type: "post",
contentType: "application/json;charset=utf-8",
data: JSON.stringify({name: "aaa", foo: ["bar1", "bar2"]}),
success: function (json) {
console.log(json);
}
});


// 以二进制数据形式检索请求的主体
ServletInputStream inputStream = request.getInputStream();
BufferedReader br = new BufferedReader(new InputStreamReader(inputStream));
String line = "";
StringBuilder sb = new StringBuilder();
while ((line = br.readLine()) != null) {
sb.append(line);
}
System.out.println("getInputStream:" + sb);


使用contentType为application/json，在data中传递复杂参数，并使用springmvc接收

$.ajax({
url: "http://localhost:8082/boot/request2/requestBody",
type: "post",
contentType: "application/json;charset=utf-8",
data: JSON.stringify({id: 111, name: "aaa", foo: ["bar1", "bar2"]}),
success: function (json) {
console.log(json);
}
});


@RequestMapping(value = "/requestBody")
public void RequestBody(@RequestBody User user) throws IOException {
System.out.println(user.toString());
}


url追加参数与data中放json同时使用

$.ajax({
// url: "http://localhost:8082/boot/request/parameter?userName=aaa",
url: "http://localhost:8082/boot/request2/parm?userName=aaa",
type: "post",
contentType: "application/json;charset=utf-8",
data: JSON.stringify({id: 111, name: "aaa", foo: ["bar1", "bar2"]}),
async:false,
success: function (json) {
console.log(json);
}
});


//请求中包含的参数的名称
Enumeration<String> parameterNames = request.getParameterNames();
while (parameterNames.hasMoreElements()) {
String s = parameterNames.nextElement();
System.out.println("getParameterNames:" + s);
String paraA = request.getParameter(s);
System.out.println("getParameter:" + paraA);
}
// 以二进制数据形式检索请求的主体
ServletInputStream inputStream = request.getInputStream();
BufferedReader br = new BufferedReader(new InputStreamReader(inputStream));
String line = "";
StringBuilder sb = new StringBuilder();
while ((line = br.readLine()) != null) {
sb.append(line);
}
System.out.println("getInputStream:" + sb);


@RequestMapping(value = "/parm")
public void parm(@RequestParam String userName, @RequestBody User user) throws IOException {
System.out.println("userName:" + userName);
System.out.println(user.toString());
}


参考文章：

https://www.w3cschool.cn/servlet/servlet-client-request.html

https://blog.csdn.net/qq_34129814/article/details/72604347