Is there a way to get count of number methods used in a jar file

Question

Can i have the count of all methods used in a jar file . My APK uses certain external JARS and there are a number of classes around hundred to be precise.

I have use

Answer 1

I wrote a script based on @JesusFreke's answer for this problem and for another problem (https://stackoverflow.com/a/21485222/6643139):

#!/bin/bash
unzip $1 classes.jar -d aarsize &&
  dx --dex --output=aarsize/temp.dex aarsize/classes.jar &&
  hexdump -s 88 -n 4 -e '1/4 "%d\n"' aarsize/temp.dex &&
  rm -rf aarsize

Save it to a file name "aarsize", chmod +x for it, output of aarsize your_aar_file :

$ aarsize status-bar-compat-release.aar 
Archive:  status-bar-compat-release.aar
  inflating: aarsize/classes.jar     
91

The 91 is the method counts of your aar file.

Answer 2

You can convert the jar to a dex file, and then pull the number of method references out of the header. It is stored as an unsigned little endian integer, at offset 88 (0x58).

dx --dex --output=temp.dex orig.jar
cat temp.dex | head -c 92 | tail -c 4 | hexdump -e '1/4 "%d\n"'

Keep in mind that this is the number of unique methods referenced, not the number of method references. In other words, if a particular method is referenced twice in the dex file, it will only be counted once in the count in the header. And when you import this jar into your apk, the method references that are common between the two are deduplicated, so the total method reference count of the final merged apk will be <= the sum of the two.

Answer 3

Use the http://github.com/mihaip/dex-method-counts for calculationg number of methods from everywhere (JAR, AAR, DEX, APK)

DEX or APK:

./dex-method-counts <your_file_path>.DEX or ./dex-method-counts <your_file_path>.APK

JAR

just make a DEX from JAR as it was shown above like this:

<your_path_to_android_buil_tools>/dx --dex --output=temp.dex orig.jar

and then

./dex-method-counts temp.dex

AAR

Firstly unzip it (yeah AAR it is ZIP actually) and then use classes.jar as it shown above in JAR section

unzip mylib.aar -d mylib

dx --dex --output=temp.dex mylib/classes.jar

dex-method-counts temp.dex

Answer 4

To find methods count in gradle library, you can use this - http://www.methodscount.com

It also provides plugin for android studio.

http://www.methodscount.com/plugins

Answer 5

I just wrote a python script for this to get a rough estimate

import re
import subprocess
import sys

for jarfile in sys.argv[1:]:
    class_output = subprocess.check_output(['jar', 'tf', jarfile])
    classes = [c.replace('/', '.') for c in re.findall(r'(.*)\.class', class_output)]
    methods = []
    if classes:
        def_out = subprocess.check_output(['javap', '-classpath', jarfile] + classes)
        # This is pretty hacky: look for parentheses in the declaration line.
        num_methods = sum(1 for line in def_out if '(' in line)
    else:
        num_methods = 0
    print '{} {} {}'.format(num_methods, len(classes), jarfile)

I had just run into the Android 64K method limit, and my dependencies weren't indexed by the methodcount.com service yet.

Answer 6

1. Use the jar program with the -x parameter to extract the files from your jar file.

2. Apply a decompiler to each .class file to get the number of methods in each file.

3. Add up the method counts.