Maven Plugin Guide
Integrate the Migration Toolkit for Applications into the Maven build process.
Abstract
Making open source more inclusive
Red Hat is committed to replacing problematic language in our code, documentation, and web properties. We are beginning with these four terms: master, slave, blacklist, and whitelist. Because of the enormity of this endeavor, these changes will be implemented gradually over several upcoming releases. For more details, see our CTO Chris Wright’s message.
Chapter 1. Introduction
1.1. About the Maven Plugin Guide
This guide is for engineers, consultants, and others who want to use the Migration Toolkit for Applications (MTA) to migrate Java applications or other components. It describes how to install and run the Maven plugin, review the generated reports, and take advantage of additional features.
1.2. About the Migration Toolkit for Applications
What is the Migration Toolkit for Applications?
The Migration Toolkit for Applications (MTA) is an extensible and customizable rule-based tool that simplifies the migration of Java applications.
The MTA examines application artifacts, including project source directories and application archives, then produces an HTML report that highlights areas needing changes. MTA can migrate Java applications from earlier versions of Red Hat JBoss Enterprise Application Platform or from other application servers, such as Oracle WebLogic Server or IBM WebSphere Application Server.
How does the Migration Toolkit for Applications simplify migration?
The Migration Toolkit for Applications looks for common resources and highlights technologies and known trouble spots when migrating applications. The goal is to provide a high-level view into the technologies used by the application and provide a detailed report organizations can use to estimate, document, and migrate enterprise applications to Java EE and Red Hat JBoss Enterprise Application Platform.
How do I learn more?
See the Introduction to the Migration Toolkit for Applications to learn more about the features, supported configurations, system requirements, and available tools in the Migration Toolkit for Applications.
1.3. About the Maven Plugin
The Maven plugin for the Migration Toolkit for Applications integrates into the Maven build process, allowing developers to continuously evaluate migration and modernization efforts with each iteration of source code. It provides numerous reports that highlight the analysis results, and is designed for developers who want updates with each build.
Chapter 2. Getting started
2.1. Installing the Maven Plugin
You can install the Maven plugin in your local Maven repository.
Prerequisites
- OpenJDK 1.8, OpenJDK 11, Oracle JDK 1.8, or Oracle JDK 11
- 8 GB RAM
- Maven 3.2.5 or later
-
macOS: The value of
maxprocmust be2048or greater.
Procedure
Clone the Maven plugin Github repository:
$ git clone https://github.com/windup/windup-maven-plugin.git
Navigate to the
windup-maven-plugindirectory.$ cd windup-maven-plugin
Build the project:
$ mvn clean install
The
windup-maven-pluginjar is installed in your local Maven repository.
2.2. Running the Maven Plugin
The Maven plugin is executed by including a reference to the plugin inside your application’s pom.xml file. When the application is built, the Maven plugin is executed and generates the reports for analysis.
Procedure
Add the following
<plugin>to your application’spom.xmlfile:[...] <plugin> <groupId>org.jboss.windup.plugin</groupId> <artifactId>windup-maven-plugin</artifactId> <version>5.0.Final</version> <executions> <execution> <id>run-windup</id> <phase>package</phase> <goals> <goal>windup</goal> </goals> </execution> </executions> <configuration> <offlineMode>true</offlineMode> 1 </configuration> </plugin> [...]- 1
offlineModeruns the Maven plugin in offline mode, disabling network features to improve performance.
If using Java 11, then
--add-modules=java.semust be added to theMAVEN_OPTSenvironment variable. When using older versions of Java this is not necessary, and you can proceed to the next step.export MAVEN_OPTS=--add-modules=java.se
ImportantUsing the Maven plugin on Java 11 is provided as Technology Preview only. Technology Preview features are not supported with Red Hat production service level agreements (SLAs), might not be functionally complete, and Red Hat does not recommend to use them for production. These features provide early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process.
See Technology Preview Features support scope on the Red Hat Customer Portal for information about the support scope for Technology Preview features.
Build the project:
$ mvn clean install
You can access the generated reports.
2.3. Running the Maven Plugin with multiple modules
To use the Maven plugin in a project with multiple modules, place the configuration inside the parent’s pom.xml. During execution the Maven plugin will generate a single report that contains the analysis for the parent and any child modules.
It is strongly recommended to set inherited to false in multi-module projects; otherwise, the Maven plugin will be executed when each child is compiled, resulting in multiple executions of the Maven plugin against the child modules. Setting inherited to false results in each project being analyzed a single time and drastically decreased run times.
To run the Maven plugin in a project with multiple modules perform the following steps.
Include the following plugin inside the parent project’s
pom.xml. The following is a samplepom.xmlfor a parent module.<plugin> <groupId>org.jboss.windup.plugin</groupId> <artifactId>windup-maven-plugin</artifactId> <version>5.0.Final</version> <inherited>false</inherited> <executions> <execution> <id>run-windup</id> <phase>package</phase> <goals> <goal>windup</goal> </goals> </execution> </executions> <configuration> <input>${project.basedir}</input> <offlineMode>true</offlineMode> <windupHome>>/PATH/TO/CLI/<</windupHome> </configuration> </plugin>This
pom.xmlfile differs from the default in the following attributes:-
inherited: Defined at the plugin level, this attribute indicates whether or not this configuration should be used in child modules. Set tofalsefor performance improvements. -
input: Specifies the path to the directory containing the projects to be analyzed. This attribute defaults to{project.basedir}/src/main, and should be defined if the parent project does not have source code to analyze. windupHome: A path to an extracted copy of the MTA CLI. This attribute is optional, but is recommended as a performance improvement.The above example demonstrates a set of recommended arguments.
-
Build the parent project. During the build process the Maven plugin will execute against all children in the project without further configuration.
$ mvn clean install
- Once completed, you can access the generated reports. This report contains the analysis for the parent and all children.
2.4. Accessing the report
When you execute Migration Toolkit for Applications, the report is generated in the OUTPUT_REPORT_DIRECTORY that you specify using the outputDirectory argument in the pom.xml. Upon completion of the build, you will see the following message in the build log.
Windup report created: <OUTPUT_REPORT_DIRECTORY>/index.html
The output directory contains the following files and subdirectories:
<OUTPUT_REPORT_DIRECTORY>/ ├── index.html // Landing page for the report ├── <EXPORT_FILE>.csv // Optional export of data in CSV format ├── graph/ // Generated graphs used for indexing ├── reports/ // Generated HTML reports ├── stats/ // Performance statistics
See the Review the reports section of the MTA CLI Guide for information on the MTA reports and how to use them to assess your migration or modernization effort.
Chapter 3. Exporting the report in CSV format
MTA provides the ability to export the report data, including the classifications and hints, to a flat file on your local file system. The export function currently supports the CSV file format, which presents the report data as fields separated by commas (,).
The CSV file can be imported and manipulated by spreadsheet software such as Microsoft Excel, OpenOffice Calc, or LibreOffice Calc. Spreadsheet software provides the ability to sort, analyze, evaluate, and manage the result data from an MTA report.
3.1. Exporting the report
To export the report as a CSV file, run MTA with the exportCSV argument set to true.
A CSV file is created in the directory specified by the --output argument for each application analyzed. All discovered issues, spanning all the analyzed applications, are included in AllIssues.csv file.
The CSV files are exported to the directory specified by the outputDirectory argument.
3.2. Importing the CSV file into a spreadsheet program
- Launch the spreadsheet software, for example, Microsoft Excel.
- Choose File → Open.
- Browse to the CSV exported file and select it.
- The data is now ready to analyze in the spreadsheet software.
3.3. About the CSV data structure
The CSV formatted output file contains the following data fields:
- Rule Id
- The ID of the rule that generated the given item.
- Problem type
- hint or classification
- Title
- The title of the classification or hint. This field summarizes the issue for the given item.
- Description
- The detailed description of the issue for the given item.
- Links
- URLs that provide additional information about the issue. A link consists of two attributes: the link and a description of the link.
- Application
- The name of the application for which this item was generated.
- File Name
- The name of the file for the given item.
- File Path
- The file path for the given item.
- Line
- The line number of the file for the given item.
- Story points
- The number of story points, which represent the level of effort, assigned to the given item.
Appendix A. Reference material
A.1. About Maven Plugin arguments
The following is a detailed description of the available MTA Maven plugin arguments.
Table A.1. MTA Maven plugin arguments
| Argument | Description |
|---|---|
| customLoggingPropertiesFile |
An absolute path to a |
| disableTattletale |
Flag to disable generation of the Tattletale report. If both |
| enableCompatibleFilesReport | Flag to enable generation of the Compatible Files report. Due to processing all files without found issues, this report may take a long time for large applications. |
| enableTattletale |
Flag to enable generation of a Tattletale report for each application. This option is enabled by default when |
| excludePackages | A list of packages to exclude from evaluation. For example, entering "com.mycompany.commonutilities" would exclude all classes whose package name begins with "com.mycompany.commonutilities". |
| excludeTags | A list of tags to exclude. When specified, rules with these tags will not be processed. |
| explodedApps | Flag to indicate that the provided input directory contains source files for a single application. |
| exportCSV |
Flag to export the report data to a CSV file on your local file system. MTA creates the file in the directory specified by the |
| includeTags | A list of tags to use. When specified, only rules with these tags will be processed. |
| inputDirectory |
Specify the path to the directory containing the applications to be analyzed. This argument defaults to |
| keepWorkDirs | Flag to instruct MTA to not delete temporary working files, such as the graph database and unzipped archives. This is useful for debugging purposes. |
| packages | A list of the packages to be evaluated by MTA. This argument is required. |
| offlineMode | Flag to operate in offline mode, disabling network access features, such as scheme validation. Used to improve performance. |
| outputDirectory |
Specify the path to the directory to output the report information generated by MTA. This argument defaults to |
| overwrite |
Flag to force delete the existing output directory specified by Warning Be careful not to specify a report output directory that contains important information! |
| sourceTechnologies |
A list of one or more source technologies, servers, platforms, or frameworks to migrate from. This argument, in conjunction with the |
| sourceMode |
Flag to indicate that the application to be evaluated contains source files rather than compiled binaries. Defaults to |
| targetTechnologies |
A list of one or more target technologies, servers, platforms, or frameworks to migrate to. This argument, in conjunction with the |
| userIgnorePath | Specify a location for MTA to identify files that should be ignored. |
| userRulesDirectory |
Specify a location for MTA to look for custom MTA rules. The value can be a directory containing ruleset files or a single ruleset file. The ruleset files must use the |
| windupHome | An optional argument that points to the root of an extracted MTA CLI. By referencing a local installation of the CLI, the Maven plugin has direct access to all of the indexes, resulting in a performance increase. |
| windupVersion | Specify the version of MTA to run. By default, this is the Maven plugin’s build version. |
A.1.1. Specifying the input directory
A path to the file or directory containing one or more applications to be analyzed. This defaults to {project.basedir}/src/main/.
Usage
<inputDirectory>
<INPUT_ARCHIVE_OR_DIRECTORY>
</inputDirectory>
Depending on whether the input file type provided to the inputDirectory argument is a file or directory, it will be evaluated as follows depending on the additional arguments provided.
- Directory
--explodedApp --sourceMode Neither Argument The directory is evaluated as a single application.
The directory is evaluated as a single application.
Each subdirectory is evaluated as an application.
- File
--explodedApp --sourceMode Neither Argument Argument is ignored; the file is evaluated as a single application.
The file is evaluated as a compressed project.
The file is evaluated as a single application.
A.1.2. Specifying the output directory
Specify the path to the directory to output the report information generated by MTA.
Usage
<outputDirectory>
<OUTPUT_REPORT_DIRECTORY>
</outputDirectory>
-
If omitted, the report will be generated in the
{project.build.directory}/windup-reportdirectory. -
If the output directory exists, it will be overwritten based on the value of the
overwriteargument. This argument defaults totrue, and causes MTA to delete and recreate the directory.
A.1.3. Setting the source technology
A list of one or more source technologies, servers, platforms, or frameworks to migrate from. This argument, in conjunction with the targetTechnologies argument, helps to determine which rulesets are used.
Usage
<sourceTechnologies>
<source>eap:6</source>
</sourceTechnologies>
The sourceTechnologies argument now provides version support, which follows the Maven version range syntax. This instructs MTA to only run the rulesets matching the specified versions. For example, <source>eap:5</source>.
A.1.4. Setting the target argument
A list of one or more target technologies, servers, platforms, or frameworks to migrate to. This argument, in conjunction with the sourceTechnologies argument, helps to determine which rulesets are used. This argument is required
Usage
<targetTechnologies> <target>eap:7</target> </targetTechnologies>
The targetTechnologies argument now provides version support, which follows the Maven version range syntax. This instructs MTA to only run the rulesets matching the specified versions. For example, <target>eap:7</target>.
When migrating to JBoss EAP, be sure to specify the version in the target, for example, eap:6. Specifying only eap will run rulesets for all versions of JBoss EAP, including those not relevant to your migration path.
See Supported migration paths in the MTA Introduction to the Migration Toolkit for Applications for which JBoss EAP version is appropriate for your source platform.
A.1.5. Selecting packages
A list of the packages to be evaluated by MTA. It is highly recommended to use this argument.
Usage
<packages>
<package>
<PACKAGE_1>
</package>
<package>
<PACKAGE_2>
</package>
</packages>
In most cases, you are interested only in evaluating custom application class packages and not standard Java EE or third party packages. The
<PACKAGE_N>argument is a package prefix; all subpackages will be scanned. For example, to scan the packagescom.mycustomappandcom.myotherapp, use the following snippet in yourpom.xml.<packages> <package>com.mycustomapp</package> <package>com.myotherapp</package> </packages>
-
While you can provide package names for standard Java EE third party software like
org.apache, it is usually best not to include them as they should not impact the migration effort.
A.2. Default logging.properties in the Maven Plugin
The default logging.properties file included with the Maven plugin is provided below. This configuration omits many extraneous messages while allowing you to view the progress of the Maven plugin.
Default logging.properties file
# Licensed under the Eclipse Public License version 1.0, available at # http://www.eclipse.org/legal/epl-v10.html # # Additional loggers to configure (the root logger is always configured) #loggers= handlers=java.util.logging.ConsoleHandler .level=INFO #java.util.logging.ConsoleHandler.level=INFO #loggers=org.jboss.forge,org.jboss.weld,org.xnio,org.jboss.forge,org.ocpsoft.rewrite,org.jboss.windup.graph.GraphModelScanner,org.jboss.windup.reporting.xml.ClassificationHandler,org.jboss.windup.graph.GraphTyp$ org.jboss.forge.level=SEVERE org.janusgraph.level=SEVERE org.janusgraph.diskstorage.berkeleyje.BerkeleyJEKeyValueStore.level=SEVERE org.janusgraph.diskstorage.berkeleyje.level=SEVERE org.jboss.weld.level=SEVERE org.xnio.level=SEVERE org.jboss.forge.level=SEVERE org.ocpsoft.rewrite.level=SEVERE org.jboss.windup.graph.GraphModelScanner.level=SEVERE org.jboss.windup.reporting.xml.ClassificationHandler.level=SEVERE org.jboss.windup.graph.GraphTypeManager.level=SEVERE org.jboss.windup.graph.GraphContextImpl.level=SEVERE org.jboss.windup.rules.files.FileMapping.level=SEVERE org.jboss.windup.exec.level=SEVERE org.jboss.windup.config.level=SEVERE com.thinkaurelius.level=SEVERE org.jboss.windup=INFO
A.3. About rule story points
A.3.1. What are story points?
Story points are an abstract metric commonly used in Agile software development to estimate the level of effort needed to implement a feature or change.
The Migration Toolkit for Applications uses story points to express the level of effort needed to migrate particular application constructs, and the application as a whole. It does not necessarily translate to man-hours, but the value should be consistent across tasks.
A.3.2. How story points are estimated in rules
Estimating the level of effort for the story points for a rule can be tricky. The following are the general guidelines MTA uses when estimating the level of effort required for a rule.
| Level of Effort | Story Points | Description |
|---|---|---|
| Information | 0 | An informational warning with very low or no priority for migration. |
| Trivial | 1 | The migration is a trivial change or a simple library swap with no or minimal API changes. |
| Complex | 3 | The changes required for the migration task are complex, but have a documented solution. |
| Redesign | 5 | The migration task requires a redesign or a complete library change, with significant API changes. |
| Rearchitecture | 7 | The migration requires a complete rearchitecture of the component or subsystem. |
| Unknown | 13 | The migration solution is not known and may need a complete rewrite. |
A.3.3. Task category
In addition to the level of effort, you can categorize migration tasks to indicate the severity of the task. The following categories are used to group issues to help prioritize the migration effort.
- Mandatory
- The task must be completed for a successful migration. If the changes are not made, the resulting application will not build or run successfully. Examples include replacement of proprietary APIs that are not supported in the target platform.
- Optional
- If the migration task is not completed, the application should work, but the results may not be optimal. If the change is not made at the time of migration, it is recommended to put it on the schedule soon after your migration is completed. An example of this would be the upgrade of EJB 2.x code to EJB 3.
- Potential
- The task should be examined during the migration process, but there is not enough detailed information to determine if the task is mandatory for the migration to succeed. An example of this would be migrating a third-party proprietary type where there is no directly compatible type.
- Information
-
The task is included to inform you of the existence of certain files. These may need to be examined or modified as part of the modernization effort, but changes are typically not required. An example of this would be the presence of a logging dependency or a Maven
pom.xml.
For more information on categorizing tasks, see Using Custom Rule Categories in the Rules Development Guide.
A.4. Additional resources
A.4.1. Getting involved
To help the Migration Toolkit for Applications cover most application constructs and server configurations, including yours, you can help with any of the following items.
- Send an email to jboss-migration-feedback@redhat.com and let us know what MTA migration rules should cover.
- Provide example applications to test migration rules.
Identify application components and problem areas that may be difficult to migrate.
- Write a short description of these problem migration areas.
- Write a brief overview describing how to solve the problem migration areas.
- Try Migration Toolkit for Applications on your application. Be sure to report any issues you encounter.
Contribute to the Migration Toolkit for Applications rules repository.
- Write a Migration Toolkit for Applications rule to identify or automate a migration process.
- Create a test for the new rule.
- Details are provided in the Rules Development Guide.
Contribute to the project source code.
- Create a core rule.
- Improve MTA performance or efficiency.
- See the Core Development Guide for information about how to configure your environment and set up the project.
Any level of involvement is greatly appreciated!
A.4.2. Resources
- MTA forums: https://developer.jboss.org/en/windup
MTA JIRA issue trackers
- Core MTA: https://issues.jboss.org/browse/WINDUP
- MTA Rules: https://issues.jboss.org/browse/WINDUPRULE
- MTA mailing list: jboss-migration-feedback@redhat.com
-
MTA IRC channel: Server FreeNode (
irc.freenode.net), channel#windup(transcripts).
A.4.3. Reporting issues with MTA
The Migration Toolkit for Applications uses JIRA as its issue tracking system. If you encounter an issue executing MTA, please file a JIRA Issue.
If you do not have a JIRA user account, you must create an account in order to create a JIRA issue.
A.4.3.1. Creating a JIRA issue
Open a browser and navigate to the JIRA Create issue page.
If you have not yet logged in, click the Log In link at the top right side of the page and enter your credentials.
Choose the following options and click the Next button.
Project
For core MTA issues, choose Migration Toolkit for Applications (WINDUP).
For issues with MTA rules, choose: Migration Toolkit for Applications rules (WINDUPRULE).
- Issue Type: Bug
On the next screen complete the following fields.
- Summary: Enter a brief description of the problem or issue.
- Environment: Provide the details of your operating system, version of Java, and any other pertinent information.
- Description: Provide a detailed description of the issue. Be sure to include logs and exceptions traces.
- Attachment: If the application or archive causing the issue does not contain sensitive information and you are comfortable sharing it with the MTA development team, attach it to the issue using the browse button.
- Click the Create button to create the JIRA issue.
Revised on 2021-01-25 11:55:47 UTC
