public final class ClassDataAbstractionCouplingCheck extends AbstractClassCouplingCheck
This metric measures the number of instantiations of other classes within the given class. This type of coupling is not caused by inheritance or the object oriented paradigm. Generally speaking, any data type with other data types as members or local variable that is an instantiation (object) of another class has data abstraction coupling (DAC). The higher the DAC, the more complex the structure of the class.
This check processes files in the following way:
import java.math.BigDecimal),
or the class was referenced with the package name (i.e. java.math.BigDecimal value)
and the package was added to the excludedPackages parameter, the class
does not increase complexity.
excludedClasses parameter,
the class does not increase complexity.
max - Specify the maximum threshold allowed.
Default value is 7.
excludedClasses - Specify user-configured class names to ignore.
Default value is ArrayIndexOutOfBoundsException, ArrayList, Boolean, Byte,
Character, Class, Deprecated, Deque, Double, Exception, Float, FunctionalInterface,
HashMap, HashSet, IllegalArgumentException, IllegalStateException,
IndexOutOfBoundsException, Integer, LinkedList, List, Long, Map, NullPointerException,
Object, Override, Queue, RuntimeException, SafeVarargs, SecurityException, Set, Short,
SortedMap, SortedSet, String, StringBuffer, StringBuilder, SuppressWarnings, Throwable,
TreeMap, TreeSet, UnsupportedOperationException, Void, boolean, byte, char, double,
float, int, long, short, void.
excludeClassesRegexps - Specify user-configured regular
expressions to ignore classes.
Default value is ^$.
excludedPackages - Specify user-configured packages to ignore.
Default value is {}.
To configure the check:
<module name="ClassDataAbstractionCoupling"/>
To configure the check with a threshold of 5:
<module name="ClassDataAbstractionCoupling"> <property name="max" value="5"/> </module>
To configure the check with two excluded classes HashMap and HashSet:
<module name="ClassDataAbstractionCoupling"> <property name="excludedClasses" value="HashMap, HashSet"/> </module>
To configure the check with two regular expressions ^Array.* and .*Exception$:
<module name="ClassDataAbstractionCoupling">
<property name="excludeClassesRegexps"
value="^Array.*, .*Exception$"/>
</module>
The following example demonstrates usage of excludedClasses and excludeClassesRegexps properties
Expected result is one class Date
<module name="ClassDataAbstractionCoupling"> <property name="excludedClasses" value="ArrayList"/> <property name="excludeClassesRegexps" value="^Hash.*"/> </module>
public class InputClassCoupling {
public Set _set = new HashSet();
public Map _map = new HashMap();
public List<String> _list = new ArrayList<>();
public Date _date = new Date();
}
To configure the check with two excluded classes HashMap and HashSet:
<module name="ClassDataAbstractionCoupling"> <property name="excludedClasses" value="HashMap, HashSet"/> </module>
To configure the check with two regular expressions ^Array.* and .*Exception$:
<module name="ClassDataAbstractionCoupling"> <property name="excludeClassesRegexps" value="^Array.*, .*Exception$"/> </module>
The following example demonstrates usage of excludedClasses and excludeClassesRegexps properties
Expected result is one class Date
<module name="ClassDataAbstractionCoupling"> <property name="excludedClasses" value="ArrayList"/> <property name="excludeClassesRegexps" value="^Hash.*"/> </module>
public class InputClassCoupling {
public Set _set = new HashSet();
public Map _map = new HashMap();
public List<String> _list = new ArrayList<>();
public Date _date = new Date();
}
Override property excludedPackages to mark some packages as excluded.
Each member of excludedPackages should be a valid identifier:
java.util - valid, excludes all classes inside java.util,
but not from the subpackages.
java.util. - invalid, should not end with a dot.
java.util.* - invalid, should not end with a star.
Note, that checkstyle will ignore all classes from the java.lang
package and its subpackages, even if the java.lang was not listed
in the excludedPackages parameter.
Also note, that excludedPackages will not exclude classes, imported
via wildcard (e.g. import java.math.*). Instead of wildcard import
you should use direct import (e.g. import java.math.BigDecimal).
Also note, that checkstyle will not exclude classes within the same file
even if it was listed in the excludedPackages parameter.
For example, assuming the config is
<module name="ClassDataAbstractionCoupling"> <property name="excludedPackages" value="a.b"/> </module>
And the file a.b.Foo.java is:
package a.b;
import a.b.Bar;
import a.b.c.Baz;
public class Foo {
public Bar bar; // Will be ignored, located inside ignored a.b package
public Baz baz; // Will not be ignored, located inside a.b.c package
public Data data; // Will not be ignored, same file
class Data {
public Foo foo; // Will not be ignored, same file
}
}
The bar member will not be counted, since the a.b added
to the excludedPackages. The baz member will be counted,
since the a.b.c was not added to the excludedPackages.
The data and foo members will be counted, as they are inside same file.
Example of usage:
<module name="ClassDataAbstractionCoupling"> <property name="excludedPackages" value="java.util, java.math"/> </module>
AutomaticBean.OutputStreamOptions| Modifier and Type | Field and Description |
|---|---|
static java.lang.String |
MSG_KEY
A key is pointing to the warning message text in "messages.properties"
file.
|
| Constructor and Description |
|---|
ClassDataAbstractionCouplingCheck()
Creates bew instance of the check.
|
| Modifier and Type | Method and Description |
|---|---|
int[] |
getAcceptableTokens()
The configurable token set.
|
protected java.lang.String |
getLogMessageId()
Returns message key we use for log violations.
|
int[] |
getRequiredTokens()
The tokens that this check must be registered for.
|
beginTree, getDefaultTokens, leaveToken, setExcludeClassesRegexps, setExcludedClasses, setExcludedPackages, setMax, visitTokenclearMessages, destroy, finishTree, getFileContents, getLine, getLines, getMessages, getTabWidth, getTokenNames, init, isCommentNodesRequired, log, log, log, setFileContents, setTabWidth, setTokensfinishLocalSetup, getCustomMessages, getId, getMessageBundle, getSeverity, getSeverityLevel, setId, setSeverityconfigure, contextualize, getConfiguration, setupChildpublic static final java.lang.String MSG_KEY
public ClassDataAbstractionCouplingCheck()
public int[] getRequiredTokens()
AbstractCheckgetRequiredTokens in class AbstractCheckTokenTypespublic int[] getAcceptableTokens()
AbstractCheckgetAcceptableTokens in class AbstractCheckTokenTypesprotected java.lang.String getLogMessageId()
AbstractClassCouplingCheckgetLogMessageId in class AbstractClassCouplingCheckCopyright © 2001-2019. All Rights Reserved.