Problem description:
has the name attribute in the HTML (JSP) page, but the value printed out in the background is null.

problem solved:
really spit out blood. The member variables of the action class corresponding to the (HTML) JSP should have the same value as the name attribute of the input tag in the HTML (JSP).

my struts.xml configuration

1, the Error: both Please install mysql2 package manually
A lot of what is said on the Internet is wrong, in fact, as long as the implementation of this sentence can solve the problem.

npm install mysql2 --save

 

Meet the vue has been an error assigning to rvalue solution, always thought that is a question of js code, look behind for a long time, were found in the HTML template v – model binding attribute is not defined in the data property. As follows:

<template>
    <div class="search-box">
        <div class="wrap">
            <input  v-model="searchText" class="search-input" type="text">
            <div class="search-botton"></div>
        </div>
    </div>
</template>

<script>
    export default {
        name: 'searchBox',
        data() {
            return {
            };
        }
    };
</script>

After modification:

<template>
    <div class="search-box">
        <div class="wrap">
            <input  v-model="searchText" class="search-input" type="text">
            <div class="search-botton"></div>
        </div>
    </div>
</template>

<script>
    export default {
        name: 'searchBox',
        data() {
            return {
                searchText: ''
            };
        }
    };
</script>

Solve problems.
The main thing to notice here is that in js code searchText is named in hump format, as well as in V-Model. Props being used in the template is not the same as wanting to convert the hump in JS to a short line. This is because the attributes in HTML are case-insensitive. However, v-Model is enclosed in quotation marks, so it is case sensitive, while short lines make an error. Detailed reference: https://blog.csdn.net/yuetingzhuying/article/details/49820689