Usage

Command Line

1. Install aol cli to device

./aol.sh -i cli.apk

2. Run

# Instance layout (instance fields)./aol.sh -o instance -c java.util.HashMap# Class layout (static fields)./aol.sh -o class -c java.util.HashMap

Command Line Usage

Usage:    -i install aol cli to device    -s device serial    -o option of aol, one of [class, instance]    -c class name    -h help

Kotlin

val layout=ObjectLayout.parse(HashMap::class.java)layout.dumpToLog(classInfo=false)// Show instance layout (instance fields)layout.dumpToLog(classInfo=true)// Show class layout (static fields)

Output

Instance Layout

java.util.HashMap object internals: OFFSET  SIZE   DECLARING_CLASS             TYPE  FIELD      0     4            Object            Class  shadow$_klass_      4     4            Object              int  shadow$_monitor_      8     4       AbstractMap              Set  keySet     12     4       AbstractMap       Collection  values     16     4           HashMap              Set  entrySet     20     4           HashMap   HashMap$Node[]  table     24     4           HashMap              int  modCount     28     4           HashMap              int  size     32     4           HashMap              int  threshold     36     4           HashMap            float  loadFactorInstance size: 40 bytes

Class Layout

java.util.HashMap class internals: OFFSET  SIZE   DECLARING_CLASS          TYPE  FIELD      0     4            Object         Class  shadow$_klass_      4     4            Object           int  shadow$_monitor_      8     4             Class   ClassLoader  classLoader     12     4             Class         Class  componentType     16     4             Class        Object  dexCache     20     4             Class      ClassExt  extData     24     4             Class      Object[]  ifTable     28     4             Class        String  name     32     4             Class         Class  superClass     36     4             Class        Object  vtable     40     8             Class          long  iFields     48     8             Class          long  methods     56     8             Class          long  sFields     64     4             Class           int  accessFlags     68     4             Class           int  classFlags     72     4             Class           int  classSize     76     4             Class           int  clinitThreadId     80     4             Class           int  dexClassDefIndex     84     4             Class           int  dexTypeIndex     88     4             Class           int  numReferenceInstanceFields     92     4             Class           int  numReferenceStaticFields     96     4             Class           int  objectSize    100     4             Class           int  objectSizeAllocFastPath    104     4             Class           int  primitiveType    108     4             Class           int  referenceInstanceOffsets    112     4             Class           int  status    116     2             Class         short  copiedMethodsOffset    118     2             Class         short  virtualMethodsOffset    120   424                                  (alignment/padding gap)    544     8           HashMap          long  serialVersionUID    552     4           HashMap           int  DEFAULT_INITIAL_CAPACITY    556     4           HashMap           int  MAXIMUM_CAPACITY    560     4           HashMap           int  MIN_TREEIFY_CAPACITY    564     4           HashMap           int  TREEIFY_THRESHOLD    568     4           HashMap           int  UNTREEIFY_THRESHOLD    572     4           HashMap         float  DEFAULT_LOAD_FACTORClass size: 576 bytesSpace losses: 424 bytes internal + 0 bytes external = 424 bytes total