net.sourceforge.pmd.lang.java.rule.strings
Class InefficientEmptyStringCheckRule

java.lang.Object
  net.sourceforge.pmd.AbstractPropertySource
      net.sourceforge.pmd.lang.rule.AbstractRule
          net.sourceforge.pmd.lang.java.rule.AbstractJavaRule
              net.sourceforge.pmd.lang.java.rule.AbstractInefficientZeroCheck
                  net.sourceforge.pmd.lang.java.rule.strings.InefficientEmptyStringCheckRule

All Implemented Interfaces:

JavaParserVisitor, ImmutableLanguage, PropertySource, Rule

public class InefficientEmptyStringCheckRule
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 class net.sourceforge.pmd.AbstractPropertySource

propertyDescriptors, propertyValuesByDescriptor

Fields inherited from interface net.sourceforge.pmd.Rule

VIOLATION_SUPPRESS_REGEX_DESCRIPTOR, VIOLATION_SUPPRESS_XPATH_DESCRIPTOR

Constructor Summary

InefficientEmptyStringCheckRule()

Method Summary

boolean	appliesToClassName(String name)
boolean	isTargetMethod(JavaNameOccurrence occ) Determine if we're dealing with String.length method

Methods inherited from class net.sourceforge.pmd.lang.java.rule.AbstractInefficientZeroCheck

checkNodeAndReport, getComparisonTargets, visit

Methods inherited from class net.sourceforge.pmd.lang.java.rule.AbstractJavaRule

apply, getDeclaringType, importsPackage, isQualifiedName, isSuppressed, 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, visit, visit, visit, visit, visit, visitAll

Methods inherited from class net.sourceforge.pmd.lang.rule.AbstractRule

addExample, addRuleChainVisit, addRuleChainVisit, addViolation, addViolation, addViolation, addViolationWithMessage, addViolationWithMessage, addViolationWithMessage, deepCopyValuesTo, end, equals, getDescription, getExamples, getExternalInfoUrl, getLanguage, getMaximumLanguageVersion, getMessage, getMinimumLanguageVersion, getName, getParserOptions, getPriority, getRuleChainVisits, getRuleClass, getRuleSetName, getSince, hashCode, isDeprecated, setDeprecated, setDescription, setExternalInfoUrl, setLanguage, setMaximumLanguageVersion, setMessage, setMinimumLanguageVersion, setName, setPriority, setRuleClass, setRuleSetName, setSince, setUsesDFA, setUsesTypeResolution, start, usesDFA, usesRuleChain, usesTypeResolution

Methods inherited from class net.sourceforge.pmd.AbstractPropertySource

copyPropertyDescriptors, copyPropertyValues, definePropertyDescriptor, dysfunctionReason, getPropertiesByPropertyDescriptor, getProperty, getPropertyDescriptor, getPropertyDescriptors, hasDescriptor, ignoredProperties, setProperty, useDefaultValueFor, usesDefaultValues

Methods inherited from class java.lang.Object

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

Methods inherited from interface net.sourceforge.pmd.PropertySource

definePropertyDescriptor, dysfunctionReason, getPropertiesByPropertyDescriptor, getProperty, getPropertyDescriptor, getPropertyDescriptors, hasDescriptor, ignoredProperties, setProperty, useDefaultValueFor, usesDefaultValues

Constructor Detail

InefficientEmptyStringCheckRule

public InefficientEmptyStringCheckRule()

Method Detail

isTargetMethod

public boolean isTargetMethod(JavaNameOccurrence occ)

Determine if we're dealing with String.length method

Specified by:

isTargetMethod in class AbstractInefficientZeroCheck

Parameters:

occ - The name occurrence

Returns:

true if it's String.length, else false

appliesToClassName

public boolean appliesToClassName(String name)

Specified by:

appliesToClassName in class AbstractInefficientZeroCheck