Class StringConcatenation

java.lang.Object

edu.umd.cs.findbugs.visitclass.BetterVisitor

edu.umd.cs.findbugs.visitclass.PreorderVisitor

edu.umd.cs.findbugs.visitclass.AnnotationVisitor

edu.umd.cs.findbugs.visitclass.DismantleBytecode

edu.umd.cs.findbugs.BytecodeScanningDetector

edu.umd.cs.findbugs.bcel.OpcodeStackDetector

edu.umd.cs.findbugs.detect.StringConcatenation

All Implemented Interfaces:

Detector, Priorities, StatelessDetector, Cloneable, org.apache.bcel.classfile.Visitor

public class StringConcatenation
extends OpcodeStackDetector
implements StatelessDetector

Find occurrences of using the String "+" or "+=" operators within a loop. This is much less efficient than creating a dedicated StringBuffer object outside the loop, and then appending to it.

Author:

Dave Brosius, William Pugh

Nested Class Summary

Nested classes/interfaces inherited from class OpcodeStackDetector

OpcodeStackDetector.WithCustomJumpInfo

Field Summary

Fields inherited from class OpcodeStackDetector

stack

Fields inherited from class DismantleBytecode

codeBytes, lineNumberTable, M_BR, M_CP, M_INT, M_PAD, M_R, M_UINT

Fields inherited from interface Priorities

EXP_PRIORITY, HIGH_PRIORITY, IGNORE_PRIORITY, LOW_PRIORITY, NORMAL_PRIORITY

Constructor Summary

Constructors

Constructor	Description
StringConcatenation(BugReporter bugReporter)

Method Summary

Modifier and Type	Method	Description
void	sawOpcode(int seen)	By default, this method will not be called when stack is TOP.
void	visit(org.apache.bcel.classfile.Method obj)

Methods inherited from class OpcodeStackDetector

afterOpcode, beforeOpcode, getStack, isUsingCustomUserValue, visitCode

Methods inherited from class BytecodeScanningDetector

getClassContext, report, shouldVisitCode, visitClassContext

Methods inherited from class DismantleBytecode

areOppositeBranches, atCatchBlock, getBranchFallThrough, getBranchOffset, getBranchTarget, getClassConstantOperand, getClassDescriptorOperand, getCodeByte, getConstantRefOperand, getDefaultSwitchOffset, getDottedClassConstantOperand, getFieldDescriptorOperand, getIntConstant, getLongConstant, getMaxPC, getMethodDescriptorOperand, getNameConstantOperand, getNextCodeByte, getNextOpcode, getNextPC, getOpcode, getPC, getPrevOpcode, getRefFieldIsStatic, getRegisterOperand, getSigConstantOperand, getStringConstantOperand, getSwitchLabels, getSwitchOffsets, getXClassOperand, getXFieldOperand, getXMethodOperand, isBranch, isIf, isMethodCall, isRegisterLoad, isRegisterStore, isRegisterStore, isReturn, isShift, isSwitch, isWideOpcode, normalizeNullComparison, printOpCode, sawBranchTo, sawClass, sawDouble, sawField, sawFloat, sawIMethod, sawInt, sawLong, sawMethod, sawRegister, sawString, visit

Methods inherited from class AnnotationVisitor

getAnnotationParameterAsEnum, getAnnotationParameterAsString, getAnnotationParameterAsStringArray, visitAnnotation, visitAnnotation, visitParameterAnnotation, visitParameterAnnotation, visitSyntheticParameterAnnotation

Methods inherited from class PreorderVisitor

amVisitingMainMethod, asUnsignedByte, doVisitMethod, getClassDescriptor, getClassName, getCode, getConstantPool, getDottedClassName, getDottedMethodSig, getDottedSuperclassName, getField, getFieldDescriptor, getFieldIsStatic, getFieldName, getFieldSig, getFullyQualifiedFieldName, getFullyQualifiedMethodName, getMethod, getMethodDescriptor, getMethodName, getMethodSig, getMethodVisitOrder, getNumberArguments, getNumberMethodArguments, getPackageName, getSizeOfSurroundingTryBlock, getSizeOfSurroundingTryBlock, getSourceFile, getStringFromIndex, getSuperclassName, getSurroundingCaughtExceptions, getSurroundingCaughtExceptions, getSurroundingCaughtExceptionTypes, getSurroundingTryBlock, getSurroundingTryBlock, getThisClass, getXClass, getXField, getXMethod, hasInterestingClass, hasInterestingMethod, isVisitMethodsInCallOrder, setupVisitorForClass, setVisitMethodsInCallOrder, shouldVisit, toString, visitAfter, visitAfter, visitAnnotationDefault, visitAnnotationEntry, visitBootstrapMethods, visitConstantInvokeDynamic, visitConstantMethodHandle, visitConstantMethodType, visitConstantModule, visitConstantPackage, visitConstantPool, visitEnclosingMethod, visitingField, visitingMethod, visitInnerClasses, visitJavaClass, visitLineNumberTable, visitLocalVariableTable, visitMethodParameters, visitParameterAnnotationEntry, visitStackMap, visitStackMapEntry

Methods inherited from class BetterVisitor

clone, report, 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, visitCodeException, visitConstantClass, visitConstantDouble, visitConstantFieldref, visitConstantFloat, visitConstantInteger, visitConstantInterfaceMethodref, visitConstantLong, visitConstantMethodref, visitConstantNameAndType, visitConstantString, visitConstantUtf8, visitConstantValue, visitDeprecated, visitExceptionTable, visitField, visitInnerClass, visitLineNumber, visitLocalVariable, visitLocalVariableTypeTable, visitMethod, visitSignature, visitSourceFile, visitSynthetic, visitUnknown

Methods inherited from class Object

equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface StatelessDetector

clone

Methods inherited from interface org.apache.bcel.classfile.Visitor

visitConstantDynamic, visitMethodParameter, visitModule, visitModuleExports, visitModuleMainClass, visitModuleOpens, visitModulePackages, visitModuleProvides, visitModuleRequires, visitNestHost, visitNestMembers, visitRecord, visitRecordComponent, visitStackMapType

Constructor Details

StringConcatenation

public StringConcatenation(BugReporter bugReporter)

Method Details

visit

public void visit(org.apache.bcel.classfile.Method obj)

Overrides:

visit in class BetterVisitor

sawOpcode

public void sawOpcode(int seen)

Description copied from class: OpcodeStackDetector

By default, this method will not be called when stack is TOP. To change this behavior, override #beforeOpcode(int) and change to return true even if stack is TOP.

see Using FindBugs for Research to learn lattice and what TOP means.

Specified by:

sawOpcode in class OpcodeStackDetector

See Also:

• OpcodeStackDetector.beforeOpcode(int)