Getting started with MVC(8)

最新推荐文章于 2025-08-18 18:11:53 发布

转载最新推荐文章于 2025-08-18 18:11:53 发布 · 99 阅读

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原文链接：https://my.oschina.net/hantsy/blog/661902

文章标签：

#测试 #java

为什么80%的码农都做不了架构师？>>>

Parameter conversion

Spring MVC providesConversionServiceto convert data to bean target type from from data.

In MVC, we can use customParamConverterto convert form data to the target type.

Parameter conversion

As an example, add adueDatetoTaskentity. We need to convert the form field value(it is aString) toLocalDatetype.

Create a customParamConverterProviderforLocalDate.

@Provider
public class CustomConverterProvider implements ParamConverterProvider {

    final DateTimeFormatter DATE_FORMAT = DateTimeFormatter.ISO_DATE;

    @Override
    public <T> ParamConverter<T> getConverter(Class<T> rawType, Type genericType, Annotation[] annotations) {

        if (rawType.getName().equals(LocalDate.class.getName())) {

            return new ParamConverter<T>() {
                @Override
                public T fromString(String value) {
                    return value != null ? (T) LocalDate.parse(value, DATE_FORMAT) : null;
                }

                @Override
                public String toString(T value) {
                    return value != null ? ((LocalDate) value).format(DATE_FORMAT) : "";
                }
            };
        } 
        ....
}

Add a new field dueDate toTaskForm, which type isLocalDate.
```
@NotNull
@FormParam("duedate")
private LocalDate dueDate;
```

In the view, add a new form field namedduedate.

<input type="text" id="duedate" name="duedate" class="form-control" placeholder="Due date"/>

When the form is submitted, theduedatewill be converted toLocalDatetype and bind todueDateproperty ofTaskForm.

Format

Spring provides Formatting service in the display view. eg.@DateFormatand custom Formatters.

Unfortunately, MVC does not support such features. And JSTLfmt:formatDatedoes not accept Java 8 DateTime APIs.

We can define a custom CDI beans for date formatting, and call it via expression language.

CreateRequestScopedbeanFormatters.

@RequestScoped
@Named("formatters")
public class Formatters {

    static DateTimeFormatter DATE_FORMATTER = DateTimeFormatter.ISO_DATE;

    public String formatDate(LocalDate data) {
        return DATE_FORMATTER.format(data);
    }

}

Apply it on thedueDatein the details.jspx page.

<dt>Due date:</dt>
<dd>${formatters.formatDate(details.dueDate)}</dd>

The result looks like:

date formatting result

Source Codes

Clone the codes from my github.com account.

https://github.com/hantsy/ee8-sandbox/
Open the mvc project in NetBeans IDE.
Run it on Glassfish.
After it is deployed and runging on Glassfish application server, navigate http://localhost:8080/ee8-mvc/mvc/tasks in browser.

转载于:https://my.oschina.net/hantsy/blog/661902