Return an empty array instead of null. Open
return null;
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Returning null
instead of an actual array or collection forces callers of the method to explicitly test for nullity, making them more
complex and less readable.
Moreover, in many cases, null
is used as a synonym for empty.
Noncompliant Code Example
public static List<Result> getResults() { return null; // Noncompliant } public static Result[] getResults() { return null; // Noncompliant } public static void main(String[] args) { Result[] results = getResults(); if (results != null) { // Nullity test required to prevent NPE for (Result result: results) { /* ... */ } } }
Compliant Solution
public static List<Result> getResults() { return Collections.emptyList(); // Compliant } public static Result[] getResults() { return new Result[0]; } public static void main(String[] args) { for (Result result: getResults()) { /* ... */ } }
See
- CERT, MSC19-C. - For functions that return an array, prefer returning an empty array over a null value
- CERT, MET55-J. - Return an empty array or collection instead of a null value for methods that return an array or collection
Return an empty array instead of null. Open
return null;
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- Exclude checks
Returning null
instead of an actual array or collection forces callers of the method to explicitly test for nullity, making them more
complex and less readable.
Moreover, in many cases, null
is used as a synonym for empty.
Noncompliant Code Example
public static List<Result> getResults() { return null; // Noncompliant } public static Result[] getResults() { return null; // Noncompliant } public static void main(String[] args) { Result[] results = getResults(); if (results != null) { // Nullity test required to prevent NPE for (Result result: results) { /* ... */ } } }
Compliant Solution
public static List<Result> getResults() { return Collections.emptyList(); // Compliant } public static Result[] getResults() { return new Result[0]; } public static void main(String[] args) { for (Result result: getResults()) { /* ... */ } }
See
- CERT, MSC19-C. - For functions that return an array, prefer returning an empty array over a null value
- CERT, MET55-J. - Return an empty array or collection instead of a null value for methods that return an array or collection
Line is longer than 100 characters (found 102). Open
c -> getLogger().info((String) c), c -> getLogger().warn((String) c), c -> getLogger()
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Checks for long lines.
Rationale: Long lines are hard to read in printouts or if developershave limited screen space for the source code, e.g. if the IDEdisplays additional information like project tree, class hierarchy,etc.
This documentation is written and maintained by the Checkstyle community and is covered under the same license as the Checkstyle project.
Line is longer than 100 characters (found 103). Open
return Objects.requireNonNullElse(getDmnCheckExtension().excludeList, Collections.emptyList());
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Checks for long lines.
Rationale: Long lines are hard to read in printouts or if developershave limited screen space for the source code, e.g. if the IDEdisplays additional information like project tree, class hierarchy,etc.
This documentation is written and maintained by the Checkstyle community and is covered under the same license as the Checkstyle project.
Using the '.*' form of import should be avoided - org.gradle.api.tasks.*. Open
import org.gradle.api.tasks.*;
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Checks that there are no import statements that use the *
notation.
Rationale: Importing all classes from a package or staticmembers from a class leads to tight coupling between packagesor classes and might lead to problems when a new version of alibrary introduces name clashes.
This documentation is written and maintained by the Checkstyle community and is covered under the same license as the Checkstyle project.
Abbreviation in name 'classpathURLs' must contain no more than '2' consecutive capital letters. Open
final URL[] classpathURLs = files.stream()
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Validates abbreviations (consecutive capital letters) length in identifier name,it also allows to enforce camel case naming. Please read more atGoogle Style Guideto get to know how to avoid long abbreviations in names.
allowedAbbreviationLength
specifies how many consecutive capital letters areallowed in the identifier.A value of 3 indicates that up to 4 consecutive capital letters are allowed,one after the other, before a violation is printed. The identifier 'MyTEST' would beallowed, but 'MyTESTS' would not be.A value of 0 indicates that only 1 consecutive capital letter is allowed. Thisis what should be used to enforce strict camel casing. The identifier 'MyTest' wouldbe allowed, but 'MyTEst' would not be.
ignoreFinal
, ignoreStatic
, and ignoreStaticFinal
control whether variables with the respective modifiers are to be ignored.Note that a variable that is both static and final will always be considered underignoreStaticFinal
only, regardless of the values of ignoreFinal
and ignoreStatic
. So for example if ignoreStatic
is true butignoreStaticFinal
is false, then static final variables will not be ignored.
This documentation is written and maintained by the Checkstyle community and is covered under the same license as the Checkstyle project.
Line is longer than 100 characters (found 103). Open
return (DmnCheckExtension) getExtensions().getByName(DmnCheckGradlePlugin.DMN_CHECK_EXTENSION);
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- Exclude checks
Checks for long lines.
Rationale: Long lines are hard to read in printouts or if developershave limited screen space for the source code, e.g. if the IDEdisplays additional information like project tree, class hierarchy,etc.
This documentation is written and maintained by the Checkstyle community and is covered under the same license as the Checkstyle project.