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Walkmod plugin to automatically fix the reported problems by PMD
<?xml version="1.0"?>
<ruleset name="Unnecessary"
xmlns="http://pmd.sourceforge.net/ruleset/2.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://pmd.sourceforge.net/ruleset/2.0.0 http://pmd.sourceforge.net/ruleset_2_0_0.xsd">
<description>
The Unnecessary Ruleset contains a collection of rules for unnecessary code.
</description>
<rule name="UnnecessaryConversionTemporary"
since="0.1"
message="Avoid unnecessary temporaries when converting primitives to Strings"
class="net.sourceforge.pmd.lang.java.rule.unnecessary.UnnecessaryConversionTemporaryRule"
externalInfoUrl="https://pmd.github.io/pmd-5.4.1/pmd-java/rules/java/unnecessary.html#UnnecessaryConversionTemporary">
<description>
Avoid the use temporary objects when converting primitives to Strings. Use the static conversion methods
on the wrapper classes instead.
</description>
<priority>3</priority>
<example>
<![CDATA[
public String convert(int x) {
String foo = new Integer(x).toString(); // this wastes an object
return Integer.toString(x); // preferred approach
}
]]>
</example>
</rule>
<rule name="UnnecessaryReturn"
since="1.3"
message="Avoid unnecessary return statements"
class="net.sourceforge.pmd.lang.java.rule.unnecessary.UnnecessaryReturnRule"
externalInfoUrl="https://pmd.github.io/pmd-5.4.1/pmd-java/rules/java/unnecessary.html#UnnecessaryReturn">
<description>
Avoid the use of unnecessary return statements.
</description>
<priority>3</priority>
<example>
<![CDATA[
public class Foo {
public void bar() {
int x = 42;
return;
}
}
]]>
</example>
</rule>
<rule name="UnnecessaryFinalModifier"
language="java"
since="3.0"
message="Unnecessary final modifier in final class"
class="net.sourceforge.pmd.lang.rule.XPathRule"
externalInfoUrl="https://pmd.github.io/pmd-5.4.1/pmd-java/rules/java/unnecessary.html#UnnecessaryFinalModifier">
<description>
When a class has the final modifier, all the methods are automatically final and do not need to be
tagged as such.
</description>
<priority>3</priority>
<properties>
<property name="xpath">
<value>
<![CDATA[
//ClassOrInterfaceDeclaration[@Final='true' and @Interface='false']
/ClassOrInterfaceBody/ClassOrInterfaceBodyDeclaration/MethodDeclaration[@Final='true']
]]>
</value>
</property>
</properties>
<example>
<![CDATA[
public final class Foo {
// This final modifier is not necessary, since the class is final
// and thus, all methods are final
private final void foo() {
}
}
]]>
</example>
</rule>
<rule name="UselessOverridingMethod"
since="3.3"
message="Overriding method merely calls super"
class="net.sourceforge.pmd.lang.java.rule.unnecessary.UselessOverridingMethodRule"
externalInfoUrl="https://pmd.github.io/pmd-5.4.1/pmd-java/rules/java/unnecessary.html#UselessOverridingMethod">
<description>
The overriding method merely calls the same method defined in a superclass.
</description>
<priority>3</priority>
<example><![CDATA[
public void foo(String bar) {
super.foo(bar); // why bother overriding?
}
public String foo() {
return super.foo(); // why bother overriding?
}
@Id
public Long getId() {
return super.getId(); // OK if 'ignoreAnnotations' is false, which is the default behavior
}
]]></example>
</rule>
<rule name="UselessOperationOnImmutable"
since="3.5"
message="An operation on an Immutable object (String, BigDecimal or BigInteger) won't change the object itself"
class="net.sourceforge.pmd.lang.java.rule.unnecessary.UselessOperationOnImmutableRule"
externalInfoUrl="https://pmd.github.io/pmd-5.4.1/pmd-java/rules/java/unnecessary.html#UselessOperationOnImmutable">
<description>
An operation on an Immutable object (String, BigDecimal or BigInteger) won't change the object itself
since the result of the operation is a new object. Therefore, ignoring the operation result is an error.
</description>
<priority>3</priority>
<example>
<![CDATA[
import java.math.*;
class Test {
void method1() {
BigDecimal bd=new BigDecimal(10);
bd.add(new BigDecimal(5)); // this will trigger the rule
}
void method2() {
BigDecimal bd=new BigDecimal(10);
bd = bd.add(new BigDecimal(5)); // this won't trigger the rule
}
}
]]>
</example>
</rule>
<rule name="UnusedNullCheckInEquals"
language="java"
since="3.5"
message="Invoke equals() on the object you''ve already ensured is not null"
class="net.sourceforge.pmd.lang.rule.XPathRule"
externalInfoUrl="https://pmd.github.io/pmd-5.4.1/pmd-java/rules/java/unnecessary.html#UnusedNullCheckInEquals">
<description>
After checking an object reference for null, you should invoke equals() on that object rather than passing it to another object's equals() method.
</description>
<priority>3</priority>
<properties>
<property name="xpath">
<value>
<![CDATA[
(//PrimaryPrefix[ends-with(Name/@Image, '.equals') and Name/@Image != 'Arrays.equals'] | //PrimarySuffix[@Image='equals' and not(../PrimaryPrefix/Literal)])
/following-sibling::PrimarySuffix/Arguments/ArgumentList/Expression
/PrimaryExpression[count(PrimarySuffix)=0]/PrimaryPrefix
/Name[@Image = ./../../../../../../../../../../Expression/ConditionalAndExpression
/EqualityExpression[@Image="!=" and count(./preceding-sibling::*)=0 and
./PrimaryExpression/PrimaryPrefix/Literal/NullLiteral]
/PrimaryExpression/PrimaryPrefix/Name/@Image]
]]>
</value>
</property>
</properties>
<example>
<![CDATA[
public class Test {
public String method1() { return "ok";}
public String method2() { return null;}
public void method(String a) {
String b;
// I don't know it method1() can be "null"
// but I know "a" is not null..
// I'd better write a.equals(method1())
if (a!=null && method1().equals(a)) { // will trigger the rule
//whatever
}
if (method1().equals(a) && a != null) { // won't trigger the rule
//whatever
}
if (a!=null && method1().equals(b)) { // won't trigger the rule
//whatever
}
if (a!=null && "LITERAL".equals(a)) { // won't trigger the rule
//whatever
}
if (a!=null && !a.equals("go")) { // won't trigger the rule
a=method2();
if (method1().equals(a)) {
//whatever
}
}
}
}
]]>
</example>
</rule>
<rule name="UselessParentheses"
language="java"
since="5.0"
message="Useless parentheses."
class="net.sourceforge.pmd.lang.rule.XPathRule"
externalInfoUrl="https://pmd.github.io/pmd-5.4.1/pmd-java/rules/java/unnecessary.html#UselessParentheses">
<description>Useless parentheses should be removed.</description>
<priority>4</priority>
<properties>
<property name="xpath">
<value>
<![CDATA[
//Expression/PrimaryExpression/PrimaryPrefix/Expression
[count(*)=1][count(./CastExpression)=0][count(./ConditionalExpression[@Ternary='true'])=0]
[not(./AdditiveExpression[//Literal[@StringLiteral='true']])]
|
//Expression/ConditionalAndExpression/PrimaryExpression/PrimaryPrefix/Expression[
count(*)=1 and
count(./CastExpression)=0 and
count(./EqualityExpression/MultiplicativeExpression)=0 and
count(./ConditionalOrExpression)=0]
|
//Expression/ConditionalOrExpression/PrimaryExpression/PrimaryPrefix/Expression[
count(*)=1 and
count(./CastExpression)=0 and
count(./EqualityExpression/MultiplicativeExpression)=0]
|
//Expression/ConditionalExpression/PrimaryExpression/PrimaryPrefix/Expression[
count(*)=1 and
count(./CastExpression)=0 and
count(./EqualityExpression)=0]
|
//Expression/AdditiveExpression[not(./PrimaryExpression/PrimaryPrefix/Literal[@StringLiteral = 'true'])]/PrimaryExpression[1]/PrimaryPrefix/Expression[
count(*)=1 and
not(./CastExpression) and
not(./AdditiveExpression[@Image = '-']) and
not(./ShiftExpression) and
not(./RelationalExpression) and
not(./InstanceOfExpression) and
not(./EqualityExpression) and
not(./AndExpression) and
not(./ExclusiveOrExpression) and
not(./InclusiveOrExpression) and
not(./ConditionalAndExpression) and
not(./ConditionalOrExpression) and
not(./ConditionalExpression)]
|
//Expression/EqualityExpression/PrimaryExpression/PrimaryPrefix/Expression[
count(*)=1 and
count(./CastExpression)=0 and
count(./AndExpression)=0 and
count(./InclusiveOrExpression)=0 and
count(./ExclusiveOrExpression)=0 and
count(./ConditionalAndExpression)=0 and
count(./ConditionalOrExpression)=0 and
count(./EqualityExpression)=0]
]]>
</value>
</property>
</properties>
<example>
<![CDATA[
public class Foo {
private int _bar1;
private Integer _bar2;
public void setBar(int n) {
_bar1 = Integer.valueOf((n)); // here
_bar2 = (n); // and here
}
}
]]>
</example>
</rule>
<rule name="UselessQualifiedThis"
language="java"
since="5.4.0"
message="Useless qualified this usage in the same class."
class="net.sourceforge.pmd.lang.rule.XPathRule"
externalInfoUrl="https://pmd.github.io/pmd-5.4.1/pmd-java/rules/java/unnecessary.html#UselessQualifiedThis">
<description>Look for qualified this usages in the same class.</description>
<priority>3</priority>
<properties>
<property name="xpath">
<value>
<![CDATA[
//PrimaryExpression
[PrimaryPrefix/Name[@Image]]
[PrimarySuffix[@Arguments='false']]
[not(PrimarySuffix/MemberSelector)]
[ancestor::ClassOrInterfaceBodyDeclaration[1][@AnonymousInnerClass='false']]
/PrimaryPrefix/Name[@Image = ancestor::ClassOrInterfaceDeclaration[1]/@Image]
]]>
</value>
</property>
</properties>
<example>
<![CDATA[
public class Foo {
final Foo otherFoo = Foo.this; // use "this" directly
public void doSomething() {
final Foo anotherFoo = Foo.this; // use "this" directly
}
private ActionListener returnListener() {
return new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
doSomethingWithQualifiedThis(Foo.this); // This is fine
}
};
}
private class Foo3 {
final Foo myFoo = Foo.this; // This is fine
}
private class Foo2 {
final Foo2 myFoo2 = Foo2.this; // Use "this" direclty
}
}
]]>
</example>
</rule>
</ruleset> © 2015 - 2025 Weber Informatics LLC | Privacy Policy