net.sourceforge.pmd.rules.strings

Class InefficientEmptyStringCheck

java.lang.Object

net.sourceforge.pmd.CommonAbstractRule

net.sourceforge.pmd.AbstractJavaRule

net.sourceforge.pmd.AbstractRule

net.sourceforge.pmd.rules.AbstractInefficientZeroCheck

net.sourceforge.pmd.rules.strings.InefficientEmptyStringCheck

All Implemented Interfaces:

JavaParserVisitor, Rule

public class InefficientEmptyStringCheck
extends AbstractInefficientZeroCheck

This rule finds code which inefficiently determines empty strings. This code

         if(str.trim().length()==0){....
 

is quite inefficient as trim() causes a new String to be created. Smarter code to check for an empty string would be:

 Character.isWhitespace(str.charAt(i));
 

Author:

acaplan

Field Summary

Fields inherited from interface net.sourceforge.pmd.Rule

LOWEST_PRIORITY, PRIORITIES

Constructor Summary

Constructors

Constructor and Description
InefficientEmptyStringCheck()

Method Summary

Methods

Modifier and Type	Method and Description
boolean	appliesToClassName(java.lang.String name)
boolean	isTargetMethod(NameOccurrence occ) Determine if we're dealing with String.length method

Methods inherited from class net.sourceforge.pmd.rules.AbstractInefficientZeroCheck

visit

Methods inherited from class net.sourceforge.pmd.AbstractJavaRule

addViolation, addViolation, addViolation, addViolationWithMessage, apply, getDeclaringType, importsPackage, isQualifiedName, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visitAll

Methods inherited from class net.sourceforge.pmd.CommonAbstractRule

addExample, addProperties, addProperty, addRuleChainVisit, asFixedMap, asFixedMap, end, equals, getBooleanProperties, getBooleanProperty, getBooleanProperty, getDescription, getDoubleProperties, getDoubleProperty, getDoubleProperty, getExample, getExamples, getExternalInfoUrl, getIntProperties, getIntProperty, getIntProperty, getMessage, getName, getPriority, getPriorityName, getProperties, getRuleChainVisits, getRuleClass, getRuleSetName, getSince, getStringProperties, getStringProperty, getStringProperty, getTypeProperties, getTypeProperty, hashCode, hasProperty, include, propertiesByName, propertyDescriptorFor, setDescription, setExternalInfoUrl, setInclude, setMessage, setName, setPriority, setProperties, setProperty, setRuleClass, setRuleSetName, setSince, setUsesDFA, setUsesTypeResolution, start, usesDFA, usesRuleChain, usesTypeResolution

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

InefficientEmptyStringCheck

public InefficientEmptyStringCheck()

Method Detail

isTargetMethod

public boolean isTargetMethod(NameOccurrence occ)

Determine if we're dealing with String.length method

Specified by:

isTargetMethod in class AbstractInefficientZeroCheck

Parameters:

occ - The name occurance

Returns:

true if it's String.length, else false

appliesToClassName

public boolean appliesToClassName(java.lang.String name)

Specified by:

appliesToClassName in class AbstractInefficientZeroCheck