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Java mapping: Selma vs MapStruct [closed]

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Currently there are two main popular Java Object to Object mapping frameworks that supersede Dozer (http://dozer.sourceforge.net/documentation/mappings.html), they are:
Selma - http://www.selma-java.org/
MapStruct - http://mapstruct.org/
With the exception of this page (http://vytas.io/blog/java/java-object-to-object-mapping-which-framework-to-choose-part-2/) I haven't been able to find much online regarding which framework is better than the other, or under what circumstances they are better. Wondering if anyone you can shed some light on this. In terms of functionality based on the documents, they seem to be doing the same thing.

(Original author of Selma so slight different point of view)
Selma and MapStruct does the same job with some differences. First it appears that Selma generated code is just a bit faster than MapStruct (http://javaetmoi.com/wp-content/uploads/2015/09/2015-09-mapping-objet-objet2.png). The 0.13 release number does not really reflects the maturity of code Selma is stable and robust it is in use in production for 2 years.
The main idea behind Selma is to prohibit magic conversion and just automate all mappings without any side effects. When mapping appears to be too complex, the developer should handle it by himself using custom mappings or interceptor.
The footprint of Selma is built to be as small as possible we only depend on a JavaWriter and the JDK.
Selma tries to only use static compiled generated code without any reflection at runtime or pseudo-code written in string fields.
You can use composition to build a chain of mappers and inside a single mapper you can have global configuration that can be overwritten on a per method basis.
Compiler messages are built to give developer early feedback, tips to solve the issue and learn the API.
At the end for sure MapStruct is more feature rich but Selma gives developer all the tools needed for complex mapping with the responsibility of writing the business logic. You could also find one of the 2 APIs nicer than the other from a user perspective so best thing to do is to try both and choose the one you feel more comfortable with. It won't be time consuming.

(Original author of MapStruct here, so naturally I am biased)
Indeed, both projects are based on the same general idea of generating mapping code at compile time; I recommend you MapStruct for the following reasons:
Proven and stable codebase: MapStruct is the older of the two, coming up with the idea of mapping generation originally. It has been enhanced and polished over quite a long time, based on real-world feedback from usage in many different projects; We released the stable 1.0 Final last year
Larger developer and user community as per the number of committers (MapStruct, Selma) and user questions (MapStruct, Selma)
Feature-rich (Some things supported in MapStruct I didn't find (to the same extend) in the Selma docs):
Many built-in type conversions, including advanced support for JAXB types such as JAXBElement
Support for default values and constants
Mapping customizations through inline expressions
Sharing configurations across mappers
Nicely integrates with CDI and JSR 330 (in addition to Spring)
Eclipse plug-in avaible: Still work in progress, but its quickfixes and auto-completions are already very helpful when designing mapper interfaces
IntelliJ plug-in: helps when editing mapper interfaces via auto-completion, go to referenced properties, refactoring support etc.

CheckStyle, FindBugs, and PMD configurations without overlap

At my company we started using CheckStyle, FindBugs, and PMD to check our code quality and unify our programming styles. These tools are very effective but unfortunately they have some overlapping rule sets.
Are there configurations available online which have removed the overlapping rules?
Of course, these default rule sets are not applicable to every project but it would be a good starting point for us. We could take this default (non overlapping) configuration and adapt it to our style instead of pruning the rule sets for duplicates first.

Sonar ships with some pretty good configurations called Sonar Way and Sonar Way with FindBugs which don't appear to have any overlap between the different tools (CheckStyle, FindBugs, and PMD). They seem to fulfill my needs as a decent starting point for a configuration without all the superfluous rules.
PS I was hesitant to answer my own question but nobody else had an answer or even an insightful comment. This thread on Meta also seems to think it's okay.

Any library for clean code generation from i18n resource bundles? [closed]

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In my project I would like to have compile time checks on my existing resource bundle. I already have a set of *.properties localized files and I'm about to hook them up to some i18n tool. I was thinking about regular ResourceBundles, but I don't like the fact, that this mechanism does not guarantee any kind of checks, neither compile-time or maintenance checks like - finding duplicates or finding unused keys.
So, I'm looking for a library, which would take my existing *.properties files and converted them into neat and clean Java code, which I could use in my project.
The best possible outcome would be to have a mechanism similar to GWT i18n support. One, clean interface with all messages as a separate methods.
I have looked at jlibs and ForgeRock. I really like jlibs, but it's not a separate lib, so it's hard for me to imagine introducing so huge lib dependency just for i18n. ForgeRock does pretty much what I would like, but it produces constants rather than clean interfaces to work with, like jlibs does.
This entry blog is also helpful in understanding which approach I would like to use. I made a big research regarding available i18n tools, I just cannot find 'that one', which would suit my needs the best.
Regards.

Another library satisfying your requirements of code generation would be i18n-binder.
Personally, I would approach this problem from another angle, using the gettext framework you would mark translatable strings in the source code and generate the resource bundles from them. There are tools and editors that can then update the translations based on the extracted strings, and detect no longer used or modified strings.

I am currently working exactly on the kind of library you are looking for, check it out. It's still work in progress, but I should be having my first release fairly soon.
The first release will just contain support for annotation based translations. I don't yet have any ideas on how to migrate existing projects into c10n style, though. Any ideas, suggestions are always welcome!

To solve this problem I implemented a Message Compiler, which creates the resource bundle files and constant definitions as Java enum for the keys from one single source file. So the constants can be used in the Java source code, which is a much safer way. The message compiler cannot only be used for Java. It creates also resource files and constants for Objective-C or Swift and can be extended for other Programming environments.

I like JUnit. Not exactly what you are looking for, but by creating tests you are sure that all the items in de propertyfiles are available.

Checkstyle vs. PMD

We are introducing static analysis tools into the build system for our Java product. We are using Maven2 so Checkstyle and PMD integration come for free. However it looks like there is a large overlap in functionality between these two tools, in terms of enforcing basic style rules.
Is there a benefit from utilizing both of these? I don't want to maintain 2 tools if one will work. If we choose one, which one should we use and why?
We are also planning on using FindBugs. Are there other static analysis tools we should look at?
Update: Consensus seems to be that PMD is preferred over CheckStyle. I don't see a solid reason to use both, and I don't want to maintain 2 sets of rule files, so we will probably aim for PMD exclusively. We'll also be bringing in FindBugs, and perhaps, eventually, Macker to enforce architectural rules.

You should definitely use FindBugs. In my experience, the false-positive rate is very low, and even the least-critical warnings it reports are worth addressing to some extent.
As for Checkstyle vs. PMD, I would not use Checkstyle since it is pretty much only concerned with style. In my experience, Checkstyle will report on a ton of things that are completely irrelevant. PMD on the other hand is also able to point out questionable coding practices and its output is generally more relevant and useful.

Both softwares are useful. Checkstyle will help you during your programming by checking your coding style i.e braces, naming etc. Simple things but very numerous!
PMD will help you by checking more complicate rules like during the design of your classes, or for more special problems like implementing correctly the clone function. Simply, PMD will check your programming style
However, both softwares suffers from similar rules sometimes bad explained. With a bad configuration, you may check things twice or two opposite things i.e "Remove useless constructors" and "Always one constructor".

If we choose one, which one should we use and why?
These tools are not competing but are complementary and should be used simultaneously.
The convention type (Checkstyle) is the glue that enables people to work together and to free up their creativity instead of spending time and energy at understanding inconsistent code.
Checkstyle examples:
Is there javadoc on public methods ?
Is the project following Sun naming conventions ?
Is the code written with a consistent format ?
while PMD reminds you bad practices:
Catching an exception without doing anything
Having dead code
Too many complex methods
Direct use of implementations instead of interfaces
Implementing the hashcode() method without the not equals(Object object) method
source:
http://www.sonarsource.org/what-makes-checkstyle-pmd-findbugs-and-macker-complementary/

We use both:
Checkstyle to make sure that everyone in the team write code in a similar maner
PMD to find problematic code areas and next refactoring targets

If your primary place of use is while developing in eclipse, then CodePro from Instantiations will be best. Earlier it was a commercial tool, but now Google bought Instantiations so CodePro analytix is free now.
Check out http://code.google.com/javadevtools/download-codepro.html

If you reviewed Checkstyle, PMD and Findbugs rule lists, you have seen that all three provide valuable output and all three overlap to a degree and also bring their own, unique rules to the table. This is why tools like Sonar use all three.
That said, Findbugs has the most specific or niche rules (e.g. "Dubious catching of IllegalMonitorStateException" - how often are you likely to run into that?) so it is usable with little or no configuration and its warnings should be taken seriously. With Checkstyle and PMD the rules are more general and style-related so they should only be used with custom configuration files to spare the team from an avalanche of irrelevant feedback ("Tab char on line 5", "Tab char on line 6", "Tab char on line 7"... you get the picture). They also provide powerful tools to write your own advanced rules, e.g. the Checkstyle DescendentToken rule.
When using all three (especially with a tool like Sonar), all of them should be configured separately (takes at least a few days to cover all the rules) while paying attention to prevent duplication (all three tools detect that hashCode() has been overridden and equals() not, for example).
In summary, if you consider static code analysis valuable, rejecting the value any of the three provides makes no sense, but to use all three, you have to invest time to configure them to give you usable feedback.

Sonar (http://www.sonarsource.org/) is a very useful open platform to manage code quality, and includes Checkstyle, PMD, Findbugs and much more.
This also indicates that all 3 tools have their right to exist...

Both tools are configurable and can do just about the same things. That said, if we're talking about out-of-the-box stuff, there is a great deal of overlap, but there are distinct rules/checks as well. For example, Checkstyle has stronger support for checking Javadoc and finding magic numbers, to name a couple. Additionally, Checkstyle has an "import control" feature that looks similar to the functionality of Macker (I've not used Macker).
If there are things that are important to you that Checkstyle does out-of-the-box that PMD doesn't, you might consider a minimal Checkstyle configuration with only those checks. Then institute a policy that the Checkstyle configuration cannot grow, simply remove checks as you implement similar functionality with, say, custom PMD rules.
Also consider that if you decide that the Checkstyle "import control" feature covers what you wanted from Macker, then you could implement PMD/Checkstyle instead of PMD/Macker. Either way it's two tools, but with Checkstyle, you'd get the stuff that PMD doesn't do out-of-the-box "for free."

Checkstyle and PMD both are good at checking coding standards and are easy to extend.
But PMD has additional rules to check for cyclomatic complexity,Npath complexity,etc which allows you write healthy code.
Another advantage of using PMD is CPD (Copy/Paste Detector).It finds out code duplication across projects and is not constrained to JAVA.It works for JSP too.
Neal Ford has a good presentation on Metrics Driven Agile Development, which talks about many tools that are helpful for Java/Java EE Development

I find Checkstyle and PMD are best for enforcing style issues and simple obvious coding bugs. Although I've found that I like using Eclipse and all the warnings it provides better for that purpose. We enforce stuff by using shared preferences and marking them as actual errors. That way, they never get checked in in the first place.
What I would strongly and enthusiastically recommend is using FindBugs. Because it works at the bytecode level it can check things that are impossible at the source level. While it spits out its fair share of junks, it has found many actual and important bugs in our code.

And 10 years later ...
In 2018 I use all of them Checkstyle, PMD and FindBugs.
Start with FindBugs. Maybe add PMD and Checkstyle later.
Never blindly enforce the default rules !
Steps:
run one tool with default rules on a project which has a lot of code
adapt the rules to this project, comment out useless rules with some notes
focus on the low hanging fruits rules (NPE, logger checks, unclosed resource checks, ...)
perform some fixes for rules you find worthwhile (one at a time !)
do this for each tool but not all at once !
repeat this process
Ideally each project can have separate rules.
I like running the rules via the build (via maven plugins) and fail on rule errors once I know a project passes all the rules I defined.
This forces developers to take action, because reporting is not enough.
From that point on your project is pretty much bullet proof and you could even add more rules later on and/or write custom rules.

One point I have not seen so far is that there are plugins for IDEs that will enforce CheckStyle rulesets on your code, whereas PMD plugins will only report on violations. For example, in a multi-site project over several programming teams, it's important to actively enforce standards, rather than just to report on them.
Both tools have plugins available for IntelliJ, NetBeans, and Eclipse (in my view this covers most usage). I'm not as familiar with NetBeans, so can only comment on IntelliJ and Eclipse.
Anyway, the PMD plugins for IntelliJ, and Eclipse, will generate reports on demand on PMD violations within the project codebase.
The CheckStyle plugins, on the other hand, will highlight violations on the fly, and can (at least for IntelliJ, I have less experience with Eclipse) be configured to automatically convert some issues (e.g. for 'OneStatementPerLine', will place CR-LF between statements, for 'NeedBraces', will add braces where they are missing, etc.). Obviously, only the simpler violations can be automatically fixed, but it's still a help on legacy projects, or projects located over several locations.
'On demand' for PMD means that the developer must consciously decide to run the report. Whereas Checkstyle violations are automatically reported to them as they develop. While PMD does contain a more extensive ruleset, in my mind the automatic enforecement/reporting of violations in IDEs is worth the hassle of maintaining 2 sets of rules.
So for any projects I work on, we use both tools, Checkstyle enforced in the IDE, PMD reported in the IDE, and both reported and measured in builds (through Jenkins).

Take a look at qulice-maven-plugin that combines together Checkstyle, PMD, FindBugs and a few other static analyzers, and pre-configures them. The beauty of this combination is that you don't need to configure them individually in every project:
<plugin>
<groupId>com.qulice</groupId>
<artifactId>qulice-maven-plugin</artifactId>
<version>0.15</version>
<executions>
<execution>
<goals>
<goal>check</goal>
</goals>
</execution>
</executions>
</plugin>

I would echo the comment that PMD is the more current product for Java style/convention checking. With respect to FindBugs, many commercial development groups are using Coverity.

PMD is what I find more people referring to. Checkstyle was what people were referring to 4 years ago but I believe PMD is maintained more continuously and what other IDEs/plugins choose to work with.

I have just started to use Checkstyle and PMD. To me, PMD is more easier to create customized rules for things such that whether there exists System.gc(), Runtime.gc(), as long as you can write the XPath Query which is also not difficult at all. However, PMD has not shown me that it has the feature to show column number. So for things like check column limits. You might would like to use Checkstyle.

PMD is the finest tool when compare with checkstyles. Checkstyles may not have the capability to analyse the code while PMD offering many features to do so! Offcourse PMD has not released rules for javadoc, comments, indentations and etc. And by the way i am planning to implement these rules.......thanx

What code analysis tools do you use for your Java projects? [closed]

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Closed 10 years ago.
What code analysis tools do you use on your Java projects?
I am interested in all kinds
static code analysis tools (FindBugs, PMD, and any others)
code coverage tools (Cobertura, Emma, and any others)
any other instrumentation-based tools
anything else, if I'm missing something
If applicable, also state what build tools you use and how well these tools integrate with both your IDEs and build tools.
If a tool is only available a specific way (as an IDE plugin, or, say, a build tool plugin) that information is also worth noting.

For static analysis tools I often use CPD, PMD, FindBugs, and Checkstyle.
CPD is the PMD "Copy/Paste Detector" tool. I was using PMD for a little while before I noticed the "Finding Duplicated Code" link on the PMD web page.
I'd like to point out that these tools can sometimes be extended beyond their "out-of-the-box" set of rules. And not just because they're open source so that you can rewrite them. Some of these tools come with applications or "hooks" that allow them to be extended. For example, PMD comes with the "designer" tool that allows you to create new rules. Also, Checkstyle has the DescendantToken check that has properties that allow for substantial customization.
I integrate these tools with an Ant-based build. You can follow the link to see my commented configuration.
In addition to the simple integration into the build, I find it helpful to configure the tools to be somewhat "integrated" in a couple of other ways. Namely, report generation and warning suppression uniformity. I'd like to add these aspects to this discussion (which should probably have the "static-analysis" tag also): how are folks configuring these tools to create a "unified" solution? (I've asked this question separately here)
First, for warning reports, I transform the output so that each warning has the simple format:
/absolute-path/filename:line-number:column-number: warning(tool-name): message
This is often called the "Emacs format," but even if you aren't using Emacs, it's a reasonable format for homogenizing reports. For example:
/project/src/com/example/Foo.java:425:9: warning(Checkstyle):Missing a Javadoc comment.
My warning format transformations are done by my Ant script with Ant filterchains.
The second "integration" that I do is for warning suppression. By default, each tool supports comments or an annotation (or both) that you can place in your code to silence a warning that you want to ignore. But these various warning suppression requests do not have a consistent look which seems somewhat silly. When you're suppressing a warning, you're suppressing a warning, so why not always write "SuppressWarning?"
For example, PMD's default configuration suppresses warning generation on lines of code with the string "NOPMD" in a comment. Also, PMD supports Java's #SuppressWarnings annotation. I configure PMD to use comments containing "SuppressWarning(PMD." instead of NOPMD so that PMD suppressions look alike. I fill in the particular rule that is violated when using the comment style suppression:
// SuppressWarnings(PMD.PreserveStackTrace) justification: (false positive) exceptions are chained
Only the "SuppressWarnings(PMD." part is significant for a comment, but it is consistent with PMD's support for the #SuppressWarning annotation which does recognize individual rule violations by name:
#SuppressWarnings("PMD.CompareObjectsWithEquals") // justification: identity comparision intended
Similarly, Checkstyle suppresses warning generation between pairs of comments (no annotation support is provided). By default, comments to turn Checkstyle off and on contain the strings CHECKSTYLE:OFF and CHECKSTYLE:ON, respectively. Changing this configuration (with Checkstyle's "SuppressionCommentFilter") to use the strings "BEGIN SuppressWarnings(CheckStyle." and "END SuppressWarnings(CheckStyle." makes the controls look more like PMD:
// BEGIN SuppressWarnings(Checkstyle.HiddenField) justification: "Effective Java," 2nd ed., Bloch, Item 2
// END SuppressWarnings(Checkstyle.HiddenField)
With Checkstyle comments, the particular check violation (HiddenField) is significant because each check has its own "BEGIN/END" comment pair.
FindBugs also supports warning generation suppression with a #SuppressWarnings annotation, so no further configuration is required to achieve some level of uniformity with other tools. Unfortunately, Findbugs has to support a custom #SuppressWarnings annotation because the built-in Java #SuppressWarnings annotation has a SOURCE retention policy which is not strong enough to retain the annotation in the class file where FindBugs needs it. I fully qualify FindBugs warnings suppressions to avoid clashing with Java's #SuppressWarnings annotation:
#edu.umd.cs.findbugs.annotations.SuppressWarnings("UWF_FIELD_NOT_INITIALIZED_IN_CONSTRUCTOR")
These techniques makes things look reasonably consistent across tools. Note that having each warning suppression contain the string "SuppressWarnings" makes it easy to run a simple search to find all instances for all tools over an entire code base.

I use a combination of Cobertura, Checkstyle, (Ecl)Emma and Findbugs.
EclEmma is an awesome Eclipse plugin that shows the code coverage by coloring the java source in the editor (screenshot) - the coverage is generated by running a JUnit test. This is really useful when you are trying to figure out which lines are covered in a particular class, or if you want to see just which lines are covered by a single test. This is much more user friendly and useful than generating a report and then looking through the report to see which classes have low coverage.
The Checkstyle and Findbugs Eclipse plugins are also useful, they generate warnings in the editor as you type.
Maven2 has report plugins that work with the above tools to generate reports at build time. We use this to get overall project reports, which are more useful when you want aggregate numbers. These are generated by our CI builds, which run using Continuum.

All of the following we use and integrate easiy in both our Maven 2.x builds and Eclipse/RAD 7:
Testing - JUnit/TestNG
Code analysis - FindBugs, PMD
Code coverage - Clover
In addition, in our Maven builds we have:
JDepend
Tag checker (TODO, FIXME, etc)
Furthermore, if you're using Maven 2.x, CodeHaus has a collection of handy Maven plugins in their Mojo project.
Note: Clover has out-of-the-box integration with the Bamboo CI server (since they're both Atlassian products). There are also Bamboo plugins for FindBugs, PMD, and CheckStyle but, as noted, the free Hudson CI server has those too.

I use the static analysis built into IntelliJ IDEA. Perfect integration.
I use the code coverage built into Intellij IDEA (based on EMMA). Again, perfect integration.
This integrated solution is reliable, powerful, and easy-to-use compared to piecing together tools from various vendors.

Checkstyle is another one I've used at a previous company... it's mainly for style checking, but it can do some static analysis too. Also, Clover for code coverage, though be aware it is not a free tool.

We are using FindBugs and Checkstyle as well as Clover for Code Coverage.
I think it's important to have some kind of static analysis, supporting your development. Unfortunately it's still not widely spread that these tools are important.

We use FindBugs and JDepend integrated with Ant. We use JUnit but we're not using any coverage tool.
I'm not using it integrated to Rational Application Developer (the IDE I'm using to develop J2EE applications) because I like how neat it looks when you run javac in the Windows console. :P

I've had good luck with Cobertura. It's a code coverage tool which can be executed via your ant script as part of your normal build and can be integrated into Hudson.

Our team use PMD and Cobertura, actually our projects are maven projects and there is very simple to include plug ins for code analysis. The real question would be for specific project which analysis you need to use, my opinion is that it's you couldn't use the same plugins for each project.

in our project we use Sonar in front of checkstyle, pmd.... together with the CI (Bamboo, Hudson) we get also a nice history of our source quality and what directing we go. I do like Sonar, because you one central tool in the CI Stack that does it for you, and you can easy customize the rules for each project.

Structure 101 is good at code analysis and finding the cyclic package dependencies.

I am looking for many answers to learn about new tools and consolidate this knowledge in a one question/thread, so I doubt there will be 1 true answer to this question.
My answer to my own question is that we use:
Findbugs to look for common errors bad/coding - run from maven, and also integrates easily into Eclipse
Cobertura for our coverage reports - run from maven
Hudson also has a task-scanner plugin that will display a count of your TODO and FIXMEs, as well as show where they are in the source files.
All are integrated with Maven 1.x in our case and tied into Hudson, which runs our builds on check-in as well as extra things nightly and weekly. Hudson trend graphs our JUnit tests, coverage, findbugs, as well as open tasks. There is also a Hudson plugin that reports and graphs our compile warnings. We also have several performance tests with their own graphs of performance and memory use over time using the Hudson plots plugin as well.