Package edu.umd.cs.findbugs.detect
Class StringConcatenation
- java.lang.Object
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- All Implemented Interfaces:
Detector
,Priorities
,StatelessDetector
,java.lang.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.
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Nested Class Summary
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Nested classes/interfaces inherited from class edu.umd.cs.findbugs.bcel.OpcodeStackDetector
OpcodeStackDetector.WithCustomJumpInfo
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Field Summary
Fields Modifier and Type Field Description private BugReporter
bugReporter
private java.util.Map<java.lang.Integer,java.lang.Integer>
clobberedRegisters
(package private) static int
CONSTRUCTED_STRING_ON_STACK
private int
createPC
private static boolean
DEBUG
(package private) static int
POSSIBLE_CASE
private boolean
reportedThisMethod
(package private) static int
SEEN_APPEND1
(package private) static int
SEEN_APPEND2
(package private) static int
SEEN_NEW
(package private) static int
SEEN_NOTHING
private int
state
private int
stringSource
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Fields inherited from class edu.umd.cs.findbugs.bcel.OpcodeStackDetector
stack
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Fields inherited from class edu.umd.cs.findbugs.visitclass.DismantleBytecode
codeBytes, lineNumberTable, M_BR, M_CP, M_INT, M_PAD, M_R, M_UINT
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Fields inherited from interface edu.umd.cs.findbugs.Priorities
EXP_PRIORITY, HIGH_PRIORITY, IGNORE_PRIORITY, LOW_PRIORITY, NORMAL_PRIORITY
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Constructor Summary
Constructors Constructor Description StringConcatenation(BugReporter bugReporter)
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description private int
getRegisterOnStack()
private int
getRegisterOnStack(int idx)
private void
reset()
void
sawOpcode(int seen)
By default, this method will not be called when stack is TOP.private boolean
storeIntoRegister(int seen, int reg)
void
visit(org.apache.bcel.classfile.Method obj)
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Methods inherited from class edu.umd.cs.findbugs.bcel.OpcodeStackDetector
afterOpcode, beforeOpcode, getStack, isUsingCustomUserValue, visitCode
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Methods inherited from class edu.umd.cs.findbugs.BytecodeScanningDetector
getClassContext, report, shouldVisitCode, visitClassContext
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Methods inherited from class edu.umd.cs.findbugs.visitclass.DismantleBytecode
areOppositeBranches, atCatchBlock, getBranchFallThrough, getBranchOffset, getBranchTarget, getClassConstantOperand, getClassDescriptorOperand, getCodeByte, getConstantRefOperand, getDefaultSwitchOffset, getDottedClassConstantOperand, getFieldDescriptorOperand, getIntConstant, getLongConstant, getMaxPC, getMethodDescriptorOperand, getNameConstantOperand, getNextCodeByte, getNextOpcode, getNextPC, getOpcode, getPC, getPrevOpcode, getRefConstantOperand, getRefFieldIsStatic, getRegisterOperand, getSigConstantOperand, getStringConstantOperand, getSwitchLabels, getSwitchOffsets, getXClassOperand, getXFieldOperand, getXMethodOperand, isBranch, isMethodCall, isRegisterLoad, isRegisterStore, isRegisterStore, isReturn, isShift, isSwitch, isWideOpcode, printOpCode, sawBranchTo, sawClass, sawDouble, sawField, sawFloat, sawIMethod, sawInt, sawLong, sawMethod, sawRegister, sawString, visit
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Methods inherited from class edu.umd.cs.findbugs.visitclass.AnnotationVisitor
getAnnotationParameterAsString, getAnnotationParameterAsStringArray, visitAnnotation, visitAnnotation, visitParameterAnnotation, visitParameterAnnotation, visitSyntheticParameterAnnotation
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Methods inherited from class edu.umd.cs.findbugs.visitclass.PreorderVisitor
amVisitingMainMethod, asUnsignedByte, doVisitMethod, getClassDescriptor, getClassName, getCode, getConstantPool, getDottedClassName, getDottedFieldSig, 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
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Methods inherited from class edu.umd.cs.findbugs.visitclass.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
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Methods inherited from class java.lang.Object
equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
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Methods inherited from interface edu.umd.cs.findbugs.StatelessDetector
clone
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Methods inherited from interface org.apache.bcel.classfile.Visitor
visitConstantDynamic, visitMethodParameter, visitModule, visitModuleExports, visitModuleMainClass, visitModuleOpens, visitModulePackages, visitModuleProvides, visitModuleRequires, visitNestHost, visitNestMembers, visitRecord, visitRecordComponent, visitStackMapType
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Field Detail
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DEBUG
private static final boolean DEBUG
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SEEN_NOTHING
static final int SEEN_NOTHING
- See Also:
- Constant Field Values
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SEEN_NEW
static final int SEEN_NEW
- See Also:
- Constant Field Values
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SEEN_APPEND1
static final int SEEN_APPEND1
- See Also:
- Constant Field Values
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SEEN_APPEND2
static final int SEEN_APPEND2
- See Also:
- Constant Field Values
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CONSTRUCTED_STRING_ON_STACK
static final int CONSTRUCTED_STRING_ON_STACK
- See Also:
- Constant Field Values
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POSSIBLE_CASE
static final int POSSIBLE_CASE
- See Also:
- Constant Field Values
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bugReporter
private final BugReporter bugReporter
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reportedThisMethod
private boolean reportedThisMethod
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stringSource
private int stringSource
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createPC
private int createPC
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state
private int state
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clobberedRegisters
private java.util.Map<java.lang.Integer,java.lang.Integer> clobberedRegisters
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Constructor Detail
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StringConcatenation
public StringConcatenation(BugReporter bugReporter)
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Method Detail
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visit
public void visit(org.apache.bcel.classfile.Method obj)
- Overrides:
visit
in classBetterVisitor
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reset
private void reset()
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storeIntoRegister
private boolean storeIntoRegister(int seen, int reg)
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getRegisterOnStack
private int getRegisterOnStack()
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getRegisterOnStack
private int getRegisterOnStack(int idx)
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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 classOpcodeStackDetector
- See Also:
OpcodeStackDetector.beforeOpcode(int)
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