JSON
JSON
用于数据载体，在网络中进行数据传输
JSON基础语法
var 变量名={
"key":value,
"num":23,
"str":"",
"flag":true,
"array":[],
"obj":{}
}
获取数据：
变量名.key
JSON数据和java对象转换
使用Fastjson实现Java对象和JSON字符串的相互转换
导入坐标：
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.62</version>
</dependency>
java对象转JSON
String jsonStr=JSON.toJSONString(obj);
JSON字符串对象转java对象
User user=JSON.parseObject(jsonStr,User.class);
利用json和axios来新增用户
html部分
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<form action="" method="post">
<table>
<tr><td>用户名</td><td><input id="username" name="username" /><span id="dulp" style="color: red;display: none">用户名已存在</span></td></tr>
<tr><td>密码</td><td><input id="pwd" name="pwd" type="password" /> </td></tr>
</table>
<!--这里要实现异步请求，如果是submit为同步请求-->
<input type="button" id="btn" value="提交">
</form>
<script src="js/axios.js"></script>
<script>
document.getElementById("username").onblur=function(){
var value=this.value;
axios.get("http://localhost:8088/judgeServlet?username="+value).then(function (resp) {
if(resp.data){
document.getElementById("dulp").style.display=''
document.getElementById("btn").style.display="none"
}else {
document.getElementById("dulp").style.display="none"
document.getElementById("btn").style.display=""
}
})
}
document.getElementById("btn").onclick=function() {
//创建json对象
var formData={
username:"",
userPwd:""
};
// 将表单数据给json对象
formData.username=document.getElementById("username").value;
formData.userPwd=document.getElementById("pwd").value;
axios.post("http://localhost:8088/axiosAddServlet",formData).then(function (resp) {
if(resp.data=="success"){
location.href="http://localhost:8088/selectAllServlet";
}
})
}
</script>
</body>
</html>
对于单选框，我们需要获取全部的选择，得到哪个框被选中，如果选中，再去给值
servlet部分：
@WebServlet(urlPatterns = "/axiosAddServlet")
public class AxiosAddServlet extends HttpServlet {
private UserService userService = new UserService();
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doGet(request, response);
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
request.setCharacterEncoding("UTF-8");
//因为注册提交方式为post，想得到参数需要获取请求体：
BufferedReader reader = request.getReader();
String s = reader.readLine();
System.out.println(s);
UserInfo userInfo = JSON.parseObject(s, UserInfo.class);
userService.add(userInfo);
response.getWriter().write("success");
}
}
