Form processing and verification skills in the Spring Web Flow framework
Spring Web Flow is a process control framework based on the Spring framework, which provides a function for processing web applications and forms.When using the Spring Web Flow framework, you can process and verify form data through some techniques to ensure the correctness and integrity of the data.Next, we will introduce some form processing and verification techniques in the Spring Web Flow framework, and provide Java code examples.
1. Use the Spring Form Tag Library (Spring Form Tag Library): The Spring framework provides a form tag library that can simplify the creation and processing process of the form.Use the form tag library to generate forms by simply labeling language, and can easily bind the model attributes.For example, you can use FORM tags to create a form, and use input tags to create form fields:
jsp
<%@ taglib prefix="form" uri="http://www.springframework.org/tags/form" %>
<html>
<body>
<h2> Create users </h2>
<form:form modelAttribute="user" method="post" action="createUser">
<table>
<tr>
<td><form:label path="name">姓名：</form:label></td>
<td><form:input path="name" /></td>
</tr>
<tr>
<td> <FORM: label Path = "Age"> Age: </form: label> </td>
<td><form:input path="age" /></td>
</tr>
<tr>
<td colspan="2"><input type="submit" value="提交" /></td>
</tr>
</table>
</form:form>
</body>
</html>
2. Form verification: The Spring framework provides a convenient form verification mechanism that can use annotations or configuration files to define verification rules.Add verification annotations to the attributes of the form object, which can specify rules and error information.The example code is as follows:
public class User {
@Notempty (MESSAGE = "Name cannot be empty")
private String name;
@Min (Value = 18, Message = "Age must be greater than or equal to 18 years"))
private int age;
// omit the getter and setter method
}
In the process submitted by the form, you can use the `bindingResult` object to obtain the verification results and further process the error message.The example code is as follows:
@PostMapping("/createUser")
public String createUser(@Valid User user, BindingResult result) {
if (result.hasErrors()) {
// Process verification error
return "errorPage";
}
// Form verification passes and processes
// ...
}
3. International support: The Spring Web Flow framework provides international support, which can easily achieve multi -language form verification error information.By defining error information corresponding to different languages in the configuration file, you can automatically select the appropriate error information according to the localization settings of the client.The example configuration is as follows:
<bean id="messageSource" class="org.springframework.context.support.ReloadableResourceBundleMessageSource">
<property name="basename" value="classpath:errorMessages" />
<property name="defaultEncoding" value="UTF-8" />
</bean>
Define the error information of different languages in the configuration file `ErrorMessages.properties`. The sample code is as follows:
properties
# default properties
NotEmpty.name=The name field is required.
The above is some form processing and verification techniques in the Spring Web Flow framework.By using these techniques reasonably, it can easily process and verify the form data in the web application to provide users with a better user experience.
