Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;
//License from project: Apache License 

import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import java.io.File;

import java.lang.reflect.Constructor;
import java.lang.reflect.Method;
import android.util.DisplayMetrics;

public class Main {
    /**
     * Because of a BUG of Android (API 13-),
     * get signature info by using "getPackageArchiveInfo" of "PackageManager"
     * always causes "NullPointerException".
     * Lack of code in method "getPackageArchiveInfo":
     *     if ((flags & GET_SIGNATURES) != 0)
     *     {
     *         packageParser.collectCertificates(pkg, 0);
     *     }
     */
    @SuppressWarnings("unchecked")
    public static PackageInfo getPackageArchiveInfo(String archiveFilePath, int flags) {
        try {
            Class packageParserClass = Class.forName("android.content.pm.PackageParser");
            Class[] innerClasses = packageParserClass.getDeclaredClasses();
            Class packageParserPackageClass = null;
            for (Class innerClass : innerClasses) {
                if (0 == innerClass.getName().compareTo("android.content.pm.PackageParser$Package")) {
                    packageParserPackageClass = innerClass;
                    break;
                }
            }
            Constructor packageParserConstructor = packageParserClass.getConstructor(String.class);
            Method parsePackageMethod = packageParserClass.getDeclaredMethod("parsePackage", File.class,
                    String.class, DisplayMetrics.class, int.class);
            Method collectCertificatesMethod = packageParserClass.getDeclaredMethod("collectCertificates",
                    packageParserPackageClass, int.class);
            Method generatePackageInfoMethod = packageParserClass.getDeclaredMethod("generatePackageInfo",
                    packageParserPackageClass, int[].class, int.class, long.class, long.class);
            packageParserConstructor.setAccessible(true);
            parsePackageMethod.setAccessible(true);
            collectCertificatesMethod.setAccessible(true);
            generatePackageInfoMethod.setAccessible(true);

            Object packageParser = packageParserConstructor.newInstance(archiveFilePath);

            DisplayMetrics displayMetrics = new DisplayMetrics();
            displayMetrics.setToDefaults();

            final File sourceFile = new File(archiveFilePath);

            Object pkg = parsePackageMethod.invoke(packageParser, sourceFile, archiveFilePath, displayMetrics, 0);
            if (pkg == null) {
                return null;
            }

            if ((flags & PackageManager.GET_SIGNATURES) != 0) {
                collectCertificatesMethod.invoke(packageParser, pkg, 0);
            }

            return (PackageInfo) generatePackageInfoMethod.invoke(null, pkg, null, flags, 0, 0);
        } catch (Exception e) {
            e.printStackTrace();
        }

        return null;
    }
}