Class Classfile

java.lang.Object
io.github.classgraph.Classfile
class Classfile extends Object
A classfile binary format parser. Implements its own buffering to avoid the overhead of using DataInputStream. This class should only be used by a single thread at a time, but can be re-used to scan multiple classfiles in sequence, to avoid re-allocating buffer memory.

See the class file format spec.

  • Field Details

    • reader

      private ClassfileReader reader
      The ClassfileReader for the current classfile.

    • classpathElement

      private final ClasspathElement classpathElement
      The classpath element that contains this classfile.

    • classpathOrder

      private final List<ClasspathElement> classpathOrder
      The classpath order.

    • relativePath

      private final String relativePath
      The relative path to the classfile (should correspond to className).

    • classfileResource

      private final Resource classfileResource
      The classfile resource.

    • stringInternMap

      private final ConcurrentHashMap<String,String> stringInternMap
      The string intern map.

    • className

      private String className
      The name of the class.

    • minorVersion

      private int minorVersion
      The minor version of the classfile format.

    • majorVersion

      private int majorVersion
      The major version of the classfile format.

    • isExternalClass

      private final boolean isExternalClass
      Whether this is an external class.

    • classModifiers

      private int classModifiers
      The class modifiers.

    • isInterface

      private boolean isInterface
      Whether this class is an interface.

    • isRecord

      private boolean isRecord
      Whether this class is a record.

    • isAnnotation

      private boolean isAnnotation
      Whether this class is an annotation.

    • superclassName

      private String superclassName
      The superclass name. (can be null if no superclass, or if superclass is rejected.)

    • implementedInterfaces

      private List<String> implementedInterfaces
      The implemented interfaces.

    • classAnnotations

      private AnnotationInfoList classAnnotations
      The class annotations.

    • fullyQualifiedDefiningMethodName

      private String fullyQualifiedDefiningMethodName
      The fully qualified name of the defining method.

    • classContainmentEntries

      private List<Classfile.ClassContainment> classContainmentEntries
      Class containment entries.

    • annotationParamDefaultValues

      private AnnotationParameterValueList annotationParamDefaultValues
      Annotation default parameter values.

    • refdClassNames

      private Set<String> refdClassNames
      Referenced class names.

    • fieldInfoList

      private FieldInfoList fieldInfoList
      The field info list.

    • methodInfoList

      private MethodInfoList methodInfoList
      The method info list.

    • typeSignatureStr

      private String typeSignatureStr
      The type signature.

    • sourceFile

      private String sourceFile
      The source file, such as Classfile.java

    • classTypeAnnotationDecorators

      private List<Classfile.ClassTypeAnnotationDecorator> classTypeAnnotationDecorators
      The type annotation decorators for the ClassTypeSignature instance.

    • acceptedClassNamesFound

      private final Set<String> acceptedClassNamesFound
      The names of accepted classes found in the classpath while scanning paths within classpath elements.

    • classNamesScheduledForExtendedScanning

      private final Set<String> classNamesScheduledForExtendedScanning
      The names of external (non-accepted) classes scheduled for extended scanning (where scanning is extended upwards to superclasses, interfaces and annotations).

    • additionalWorkUnits

      private List<Scanner.ClassfileScanWorkUnit> additionalWorkUnits
      Any additional work units scheduled for scanning.

    • scanSpec

      private final ScanSpec scanSpec
      The scan spec.

    • cpCount

      private int cpCount
      The number of constant pool entries plus one.

    • entryOffset

      private int[] entryOffset
      The byte offset for the beginning of each entry in the constant pool.

    • entryTag

      private int[] entryTag
      The tag (type) for each entry in the constant pool.

    • indirectStringRefs

      private int[] indirectStringRefs
      The indirection index for String/Class entries in the constant pool.

    • NO_ANNOTATIONS

      private static final AnnotationInfo[] NO_ANNOTATIONS
      An empty array for the case where there are no annotations.

  • Constructor Details

    • Classfile

      Classfile(ClasspathElement classpathElement, List<ClasspathElement> classpathOrder, Set<String> acceptedClassNamesFound, Set<String> classNamesScheduledForExtendedScanning, String relativePath, Resource classfileResource, boolean isExternalClass, ConcurrentHashMap<String,String> stringInternMap, WorkQueue<Scanner.ClassfileScanWorkUnit> workQueue, ScanSpec scanSpec, LogNode log) throws IOException, Classfile.ClassfileFormatException, Classfile.SkipClassException
      Directly examine contents of classfile binary header to determine annotations, implemented interfaces, the super-class etc. Creates a new ClassInfo object, and adds it to classNameToClassInfoOut. Assumes classpath masking has already been performed, so that only one class of a given name will be added.
      Parameters:
      classpathElement - the classpath element
      classpathOrder - the classpath order
      acceptedClassNamesFound - the names of accepted classes found in the classpath while scanning paths within classpath elements.
      classNamesScheduledForExtendedScanning - the names of external (non-accepted) classes scheduled for extended scanning (where scanning is extended upwards to superclasses, interfaces and annotations).
      relativePath - the relative path
      classfileResource - the classfile resource
      isExternalClass - if this is an external class
      stringInternMap - the string intern map
      workQueue - the work queue
      scanSpec - the scan spec
      log - the log
      Throws:
      IOException - If an IO exception occurs.
      Classfile.ClassfileFormatException - If a problem occurs while parsing the classfile.
      Classfile.SkipClassException - if the classfile needs to be skipped (e.g. the class is non-public, and ignoreClassVisibility is false)

  • Method Details

    • scheduleScanningIfExternalClass

      private void scheduleScanningIfExternalClass(String className, String relationship, LogNode log)
      Extend scanning to a superclass, interface or annotation.
      Parameters:
      className - the class name
      relationship - the relationship type
      log - the log

    • extendScanningUpwardsFromAnnotationParameterValues

      private void extendScanningUpwardsFromAnnotationParameterValues(Object annotationParamVal, LogNode log)
      Check if scanning needs to be extended upwards from an annotation parameter value.
      Parameters:
      annotationParamVal - the AnnotationInfo object for an annotation, or for an annotation parameter value.
      log - the log

    • extendScanningUpwards

      private void extendScanningUpwards(LogNode log)
      Check if scanning needs to be extended upwards to an external superclass, interface or annotation.
      Parameters:
      log - the log

    • link

      void link(Map<String, ClassInfo> classNameToClassInfo, Map<String, PackageInfo> packageNameToPackageInfo, Map<String, ModuleInfo> moduleNameToModuleInfo)
      Link classes. Not threadsafe, should be run in a single-threaded context.
      Parameters:
      classNameToClassInfo - map from class name to class info
      packageNameToPackageInfo - map from package name to package info
      moduleNameToModuleInfo - map from module name to module info

    • intern

      private String intern(String str)
      Intern a string.
      Parameters:
      str - the str
      Returns:
      the string

    • getConstantPoolStringOffset

      private int getConstantPoolStringOffset(int cpIdx, int subFieldIdx) throws Classfile.ClassfileFormatException
      Get the byte offset within the buffer of a string from the constant pool, or 0 for a null string.
      Parameters:
      cpIdx - the constant pool index
      subFieldIdx - should be 0 for CONSTANT_Utf8, CONSTANT_Class and CONSTANT_String, and for CONSTANT_NameAndType_info, fetches the name for value 0, or the type descriptor for value 1.
      Returns:
      the constant pool string offset
      Throws:
      Classfile.ClassfileFormatException - If a problem is detected

    • getConstantPoolString

      private String getConstantPoolString(int cpIdx, boolean replaceSlashWithDot, boolean stripLSemicolon) throws Classfile.ClassfileFormatException, IOException
      Get a string from the constant pool, optionally replacing '/' with '.'.
      Parameters:
      cpIdx - the constant pool index
      replaceSlashWithDot - if true, replace slash with dot in the result.
      stripLSemicolon - if true, strip 'L' from the beginning and ';' from the end before returning (for class reference constants)
      Returns:
      the constant pool string
      Throws:
      Classfile.ClassfileFormatException - If a problem occurs.
      IOException - If an IO exception occurs.

    • getConstantPoolString

      private String getConstantPoolString(int cpIdx, int subFieldIdx) throws Classfile.ClassfileFormatException, IOException
      Get a string from the constant pool.
      Parameters:
      cpIdx - the constant pool index
      subFieldIdx - should be 0 for CONSTANT_Utf8, CONSTANT_Class and CONSTANT_String, and for CONSTANT_NameAndType_info, fetches the name for value 0, or the type descriptor for value 1.
      Returns:
      the constant pool string
      Throws:
      Classfile.ClassfileFormatException - If a problem occurs.
      IOException - If an IO exception occurs.

    • getConstantPoolString

      private String getConstantPoolString(int cpIdx) throws Classfile.ClassfileFormatException, IOException
      Get a string from the constant pool.
      Parameters:
      cpIdx - the constant pool index
      Returns:
      the constant pool string
      Throws:
      Classfile.ClassfileFormatException - If a problem occurs.
      IOException - If an IO exception occurs.

    • getConstantPoolStringFirstByte

      private byte getConstantPoolStringFirstByte(int cpIdx) throws Classfile.ClassfileFormatException, IOException
      Get the first UTF8 byte of a string in the constant pool, or '\0' if the string is null or empty.
      Parameters:
      cpIdx - the constant pool index
      Returns:
      the first byte of the constant pool string
      Throws:
      Classfile.ClassfileFormatException - If a problem occurs.
      IOException - If an IO exception occurs.

    • getConstantPoolClassName

      private String getConstantPoolClassName(int cpIdx) throws Classfile.ClassfileFormatException, IOException
      Get a string from the constant pool, and interpret it as a class name by replacing '/' with '.'.
      Parameters:
      cpIdx - the constant pool index
      Returns:
      the constant pool class name
      Throws:
      Classfile.ClassfileFormatException - If a problem occurs.
      IOException - If an IO exception occurs.

    • getConstantPoolClassDescriptor

      private String getConstantPoolClassDescriptor(int cpIdx) throws Classfile.ClassfileFormatException, IOException
      Get a string from the constant pool representing an internal string descriptor for a class name ("Lcom/xyz/MyClass;"), and interpret it as a class name by replacing '/' with '.', and removing the leading "L" and the trailing ";".
      Parameters:
      cpIdx - the constant pool index
      Returns:
      the constant pool class descriptor
      Throws:
      Classfile.ClassfileFormatException - If a problem occurs.
      IOException - If an IO exception occurs.

    • constantPoolStringEquals

      private boolean constantPoolStringEquals(int cpIdx, String asciiStr) throws Classfile.ClassfileFormatException, IOException
      Compare a string in the constant pool with a given ASCII string, without constructing the constant pool String object.
      Parameters:
      cpIdx - the constant pool index
      asciiStr - the ASCII string to compare to
      Returns:
      true, if successful
      Throws:
      Classfile.ClassfileFormatException - If a problem occurs.
      IOException - If an IO exception occurs.

    • cpReadInt

      private int cpReadInt(int cpIdx) throws IOException
      Read an int from the constant pool.
      Parameters:
      cpIdx - the constant pool index.
      Returns:
      the int
      Throws:
      IOException - If an I/O exception occurred.

    • cpReadLong

      private long cpReadLong(int cpIdx) throws IOException
      Read a long from the constant pool.
      Parameters:
      cpIdx - the constant pool index.
      Returns:
      the long
      Throws:
      IOException - If an I/O exception occurred.

    • getFieldConstantPoolValue

      private Object getFieldConstantPoolValue(int tag, char fieldTypeDescriptorFirstChar, int cpIdx) throws Classfile.ClassfileFormatException, IOException
      Get a field constant from the constant pool.
      Parameters:
      tag - the tag
      fieldTypeDescriptorFirstChar - the first char of the field type descriptor
      cpIdx - the constant pool index
      Returns:
      the field constant pool value
      Throws:
      Classfile.ClassfileFormatException - If a problem occurs.
      IOException - If an IO exception occurs.

    • readAnnotation

      private AnnotationInfo readAnnotation() throws IOException
      Read annotation entry from classfile.
      Returns:
      the annotation, as an AnnotationInfo object.
      Throws:
      IOException - If an IO exception occurs.

    • readAnnotationElementValue

      private Object readAnnotationElementValue() throws IOException
      Read annotation element value from classfile.
      Returns:
      the annotation element value
      Throws:
      IOException - If an IO exception occurs.

    • readTypePath

      private List<Classfile.TypePathNode> readTypePath() throws IOException
      Throws:
      IOException

    • readConstantPoolEntries

      private void readConstantPoolEntries(LogNode log) throws IOException
      Read constant pool entries.
      Parameters:
      log - The log
      Throws:
      IOException - Signals that an I/O exception has occurred.

    • readBasicClassInfo

      private void readBasicClassInfo() throws IOException, Classfile.ClassfileFormatException, Classfile.SkipClassException
      Read basic class information.
      Throws:
      IOException - if an I/O exception occurs.
      Classfile.ClassfileFormatException - if the classfile is incorrectly formatted.
      Classfile.SkipClassException - if the classfile needs to be skipped (e.g. the class is non-public, and ignoreClassVisibility is false)

    • readInterfaces

      private void readInterfaces() throws IOException
      Read the class' interfaces.
      Throws:
      IOException - if an I/O exception occurs.

    • readFields

      private void readFields() throws IOException, Classfile.ClassfileFormatException
      Read the class' fields.
      Throws:
      IOException - if an I/O exception occurs.
      Classfile.ClassfileFormatException - if the classfile is incorrectly formatted.

    • readMethods

      private void readMethods() throws IOException, Classfile.ClassfileFormatException
      Read the class' methods.
      Throws:
      IOException - if an I/O exception occurs.
      Classfile.ClassfileFormatException - if the classfile is incorrectly formatted.

    • readClassAttributes

      private void readClassAttributes() throws IOException, Classfile.ClassfileFormatException
      Read class attributes.
      Throws:
      IOException - if an I/O exception occurs.
      Classfile.ClassfileFormatException - if the classfile is incorrectly formatted.