Eclipse

Eclipse XPath Evaluation Plugin Example

Hello, I started using Eclipse IDE to work with XML. In this tutorial, we will learn to use the XML and XPath Editor available through the Web Tools Platform (WTP) within Eclipse.

1. Introduction

XML stands for Extensible Markup Language and is a text-based markup language derived from Standard Generalized Markup Language (SGML). XML tags identify the data and are used to store and organize the data, rather than specifying how to display them like HTML tags, which are used to display the data. XML is not going to replace HTML in the near future, but it introduces new possibilities by adopting many successful features of HTML.

Fig. 1: Overview to XML
Fig. 1: Overview to XML

1.1 XPath

XPath is an XML query language. It is an important and a core component of XSLT standard and is used to traverse the elements and attributes in an XML document. XPath provides various types of expressions which can be used to enquire relevant information from the XML document:

  • Structure Definitions
  • Path Expressions
  • Standard Functions
  • Solution to finding information in an XML document

Fig. 2: Overview to XPath
Fig. 2: Overview to XPath

This post details the instructions for adding XPath Plugin to the Eclipse. It is really a simple process, but I’ve detailed it out anyway.

1.2 Eclipse XPath Evaluation Plugin

Eclipse XPath Evaluation plugin provides a new view in an eclipse perspective and enables the user to evaluate XPath expressions against the active text editor containing XML and has the following features:

  • XPath 2.0 expression validation
  • Well-formed XML validation
  • Executing XPath 2.0 expressions against XML
  • Namespace support in XPath queries
  • Pretty print.

Fig. 3: Eclipse XPath Evaluation Plugin
Fig. 3: Eclipse XPath Evaluation Plugin

Supported Eclipse Versions:

  • Neon / 4.6+
  • Mars / 4.5+
  • Luna / 4.4+
  • Kepler / 4.3+
  • Juno / 4.2+
  • Indigo / 3.7+
  • Helios / 3.6+
  • Galileo / 3.5+
  • Ganymede / 3.4+

Supported Java Versions:

  • JDK 1.6 and above (from plugin version 1.4.1 onwards)
  • JDK 1.5 (up to plugin version 1.3.0)

1.3 Eclipse XPath Evaluation Plugin Installation

I’m using Eclipse Kepler SR2 and it’s probably a similar process in other versions. Below are the steps involved in the installation of this plugin.

  • Go to Help –> Install New Software…

Fig. 4: Installation Step 1
Fig. 4: Installation Step 1

  • Select the XPath Repository (https://raw.githubusercontent.com/stoupa91/eclipse-xpath-evaluation-plugin/master/eclipse-xpath-evaluation-plugin-update-site/) from the ‘Work with:‘ menu.

Fig. 5: Installation Step 2
Fig. 5: Installation Step 2

  • In the search box, enter XPath to filter the results and select ‘ Eclipse XPath Plugin‘. Click Confirm.

Fig. 6: Installation Step 3
Fig. 6: Installation Step 3

  • Accept the terms and click Finish.

Fig 7: Installation Step 4
Fig 7: Installation Step 4

  • Wait for the installation to run.

Fig. 8: Installation Step 5
Fig. 8: Installation Step 5

  • You might see this – just click OK.

Fig. 9: Installation Step 6
Fig. 9: Installation Step 6

  • Click Yes when ready.

Fig. 10: Installation Step 7
Fig. 10: Installation Step 7

  • Now you have finished installing the XPath plugin. After the restart, all you need to do is to go to Window -> Show View -> Other -> XML -> XPath. This view will be used for executing the XPath expressions.

Fig. 11: Eclipse XPath Console
Fig. 11: Eclipse XPath Console

Anyway, that was pretty easy, wasn’t it? Now, let’s start building the sample application!

2. Eclipse XPath Evaluation Plugin Tutorial

After installing and reviewing the XPath Plugin features, let us see now the XPath evaluation in action. Below are the steps involved in developing this application.

2.1 Getting Started

This section will demonstrate on how to create a Dynamic Web Java project with Eclipse. In Eclipse IDE, go to File -> New -> Dynamic web project.

Fig. 12: Create Dynamic Web Project
Fig. 12: Create Dynamic Web Project

In the New, Dynamic Project window fill in the below details and click next.

  • Enter the project name and project location.
  • Select Target runtime as Apache Tomcat v7.0 from the drop-down.

Fig. 13: Project Details
Fig. 13: Project Details

Leave everything as default in this window as we will be making the required java file at a later stage. Simply click next and we will land up on the web-module window.

Fig. 14: Java Src Window
Fig. 14: Java Src Window

In the Web Module window, leave the context_root and content_directory values as default (however, you can change the context_root but for the first application let’s keep it as a default value). Simply, check Generate web.xml deployment descriptor check box and click Finish.

Fig. 15: Web Module Window
Fig. 15: Web Module Window

Eclipse will create the project named EclipseXpathExample in the workspace and web.xml will be configured.

2.2 XPath in Action

Once the web project is created, we can now create a new XML file. Right click on the project context, and click New. Select XML file and provide a name to the file: xpathEvaluatorWelcome.xml. Click Next.

Fig. 16: XML File Creation (xpathEvaluatorWelcome.xml)
Fig. 16: XML File Creation (xpathEvaluatorWelcome.xml)

In this step, we will select the desired template to use for the new XML file. In this tutorial, we will use the already existing XML Template. Click Finish and the new XML file will be created.

Fig. 17: XML File Template Selection
Fig. 17: XML File Template Selection

Let us complete our example XML page by adding some tags.

2.3 Application Building

Here in the xpathEvaluatorWelcome.xml, we will have the basic XML components. Add the following code to it.

xpathEvaluatorWelcome.xml

<?xml version="1.0" encoding="UTF-8"?>
<company xmlns="urn:xmlns:9hoursaday-com:company">
	<staff id="101">
		<title>Mr.</title>
		<firstname>Java Code</firstname>
		<lastname>Geek</lastname>
		<nickname>JCG</nickname>
		<salary format="$">10000</salary>
	</staff>
	<staff id="102">
		<title>Mr.</title>
		<firstname>Harry</firstname>
		<lastname>Potter</lastname>
		<nickname>HP</nickname>
		<salary format="$">5000</salary>
	</staff>
</company>

3. Project Run

Once we are ready with all the changes, provide the XPath query you want to execute in the XPath combo box and press Enter. The result will be shown under the query combo box.

Query #1

//company

Fig. 18: Query #1 Output
Fig. 18: Query #1 Output

Query #2

//staff

Fig. 19: Query #2 Output
Fig. 19: Query #2 Output

Query #3

//staff/firstname

Fig. 20: Query #3 Output
Fig. 20: Query #3 Output

Query #4

//staff/nickname

Fig. 21: Query #4 Output
Fig. 21: Query #4 Output

That’s all for this post. Happy Learning!

5. Conclusion

In this article, we saw how to install the XPath Plugin in Eclipse. We also discussed what XML is and how we can easily create and edit a XML file in Eclipse.

6. Download the Eclipse Project

This was an example of Eclipse XPath Evaluation Plugin.

Download
You can download the full source code of this example here: EclipseXpathExample

Yatin

An experience full-stack engineer well versed with Core Java, Spring/Springboot, MVC, Security, AOP, Frontend (Angular & React), and cloud technologies (such as AWS, GCP, Jenkins, Docker, K8).
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Nat
Nat
1 year ago

Hello,
Thank you very much for these steps.
I have a question regarding the “result” section from Xpath evaluation.
all my search are showeed in one line and it is pretty hard to read it.
How can I put it to read the results separated?

(image attached)
I am pretty new, i am a student.

Captura de pantalla 2022-11-24 141048.png
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