Thursday, November 27, 2014

ADF - Access resources packaged in an ADF Library JAR

Oracle ADF and JDeveloper support packaging a reusable component and its resources into an ADF Library JAR. When the component is consumed by a web application, ADF and JDeveloper automatically make the resources of component available at runtime to serve requests. At most time, you don’t have to care about the detail behind the scene. But if the resources (css, js, png, jpeg, etc.) cannot be served from the ADF Library JAR, or only some special resources cannot be accessed, then this post is probably for you. As using bundled font files in a web application is getting so popular these days (e.g. Bootstrap uses font files for its glyph icons), I guess you are reading this post probably because of missing font files (eot,ttf,woff,svg).

When you deploy a project into an ADF Library JAR, JDeveloper packages artifacts under the web content root directory (if any) to the JAR. When you make use of a component from the JAR in your web application JDeveloper extends the web.xml file in your web application with two key players for accessing resources from an ADF Library JAR - the adflibResources servlet and the ADFLibraryFilter.

Here’s the entries for the adflibResources servlet:



And the entries for the ADFLibraryFilter:



Usually, JDeveloper can add these entries automatically if it’s aware that you are using a component from an ADF Library JAR, for example, when you use the wizard to create a page based on a page template exposed from the JAR. If for some reason, these entries are not there, you can surely manually add them there.

At runtime, when the web application serves a request, if a resource is not found in the web content directory of the web application, the ADFLibraryFilter forwards the request to the adflibResources servlet to load the resource from the ADF Library JAR. By default, the resources handled by the ADFLibraryFilter are files with an extension in the following list:


So, for any other type of resources, you will end up with a 404 error. Fortunately, it’s allowed to customize this list. For the Bootstrap font files case, you can customize the extension list with the include-extension-list initialization parameter of the ADFLibraryFilter like this:


Chinese Summary:

为了加载 ADF 库文档中的资源,Web 应用程序的 web.xml 文件需要配置 adflibResources servlet 以及 ADFLibraryFilter 过滤器。对于特殊文件类型的资源,例如字体文件等,还需要配置 ADFLibraryFilter 的初始化参数以允许其处理此类文件。

Sample Application:


JDeveloper Build JDEVADF_12.

Tuesday, November 25, 2014

ADF - Package reusable components into an ADF Library JAR

When we work on ADF components, we may want to reuse them across different projects, applications and teams. Oracle ADF and JDeveloper support to package reusable components and associated artifacts into an ADF Library JAR. An ADF Library JAR is a special JAR containing ADF components and appropriate control files for the components. ADF page templates is one of types of these high-level reusable components that can be packaged into an ADF Library JAR.

I’m not going to introduce how to package reusable ADF components into an ADF Library JAR in general here again, because the official documentation Developing Fusion Web Applications with Oracle Application Development Framework itself is a great resource where you can learn about it. You can find the information from the chapter 44 Reusing Application Components.

In this post, taking page templates as an example, I’ll be talking about a practical approach to package only required artifacts into an ADF Library JAR, leaving irrelevant files out of it, and still allowing us to develope and test the reusable components easily.

You can find and download sample sources for this post. The sample sources consists of two applications - the pagetemplates application for the ADF Library containing the page template, and the consumer application that uses the page template from the ADF Library:

Image: Sample Applications

To create ADF page templates as reusable components, we start from an ADF ViewController project. In the sample applications, the pagetemplates-webapp project in the pagetemplates application is such an ADF ViewController project. It uses the popular Bootstrap framework to create a very simple page template. We can test the page template with test pages in the root directory of web contents.

If we create an ADF Library JAR deployment profile for the pagetemplates-webapp project to package the page template as a reusable component, we will have all the required artifacts and resources in the result ADF Library JAR. As a side-effect, some artifacts we don’t really want will also be included, such as those test pages and irrelevant metadata files, in this case, files under the WEB-INF/ directory, etc. Unfortunately, it’s now allowed to configure the files and folders that are to be packaged into an ADF Library JAR.

You can surely remove unwanted artifacts from the project to get a tidy JAR, but that will make development and testing of your page templates very hard. You might consider creating another ADF ViewController project that uses the deployed ADF Library JAR to test the page templates. Better this time, but every time you make a change to you page templates, you have to build and deploy your ADF Library JAR, and then rebuild and run your testing project to see the result. You would eventually rather stay with your untidy JAR.

To get a clean ADF Library JAR without making testing a nightmare, instead of deploying the ADF Library JAR directly from the original ADF ViewController project containing the page templates, we can create another ADF ViewController project dedicated in deployment purpose. This second project is a bare ViewController project actually, with all appropriate project source paths configured to point to the corresponding ones in the original project. With project source paths, it’s allowed to configure a list of files or folders that are to be specifically included in the current project, such that you can choose now which artifacts are going to be packaged into the ADF Library JAR deployment profile.

In the sample application, the pagetemplates-adflib project is created as an ADF ViewController project for this purpose. Once the project is created, its project source paths are set to point to the respective ones in the pagetemplates-webapp project, and choose to include or exclude selected files or folders for the current project.Particularly, In the Project Source Paths window, it looks like this:

Image: Project Properties / Project Source Paths

And in the Project Source Paths: Web Application window, the setting is as follow:

Image: Project Properties / Project Source Paths: Web Application

Finally, create an ADF Library JAR deployment profile for the pagetemplates-adflib project:

Image: Project Properties / Deployment

Note: the deploy folder is configured intentionally under the root folder containing the sample applications.

With this approach, we can develop and test the page templates in the full ADF ViewController project, and deploy the ADF Library JAR any time from the bare ViewController project. The same approach also works for other types of reusable ADF components. Enjoy!

Chinese Summary:

在开发可重用的 ADF 组件,并将其打包为 ADF 库文档时,如果不希望包含那些无关的配置文件和用于测试的文件时。可以创建两个 ADF 视图控制器项目,其中之一为完整项目,包含组件及其所需工件和资源文件,以及所有用于测试的文件。另一个为裸项目,其项目源代码路径都设置指向完整项目中的对应路径,同时设置包含在该项目中的文件或目录的列表。基于这个方法,完整的项目用于开发和测试可重用组件;而为裸项目定义一个 ADF 库文档部署概要文件,专门用于部署 ADF 库文档。

Sample Applications:


  • Mac OS X Version 10.10
  • Safari Version 8.0
  • JDeveloper Build JDEVADF_12.
  • Oracle Alta UI