1 

private String showUninstallAPKSignatures(String apkPath) {

 2         String PATH_PackageParser = "android.content.pm.PackageParser";

 3         

try {

 4             

//

 apk包的文件路径

 5 

            

//

 这是一个Package 解释器, 是隐藏的

 6 

            

//

 构造函数的参数只有一个, apk文件的路径

 7 

            

//

 PackageParser packageParser = new PackageParser(apkPath);

 8 

            Class pkgParserCls = Class.forName(PATH_PackageParser);

 9             Class[] typeArgs = 

new Class[1];

10             typeArgs[0] = String.

class;

11             Constructor pkgParserCt = pkgParserCls.getConstructor(typeArgs);

12             Object[] valueArgs = 

new Object[1];

13             valueArgs[0] = apkPath;

14             Object pkgParser = pkgParserCt.newInstance(valueArgs);

15             MediaApplication.logD(DownloadApk.

class, "pkgParser:" + pkgParser.toString());

16             

//

 这个是与显示有关的, 里面涉及到一些像素显示等等, 我们使用默认的情况

17 

            DisplayMetrics metrics = 

new DisplayMetrics();

18             metrics.setToDefaults();

19             

//

 PackageParser.Package mPkgInfo = packageParser.parsePackage(new

20 

            

//

 File(apkPath), apkPath,

21 

            

//

 metrics, 0);

22 

            typeArgs = 

new Class[4];

23             typeArgs[0] = File.

class;

24             typeArgs[1] = String.

class;

25             typeArgs[2] = DisplayMetrics.

class;

26             typeArgs[3] = Integer.TYPE;

27             Method pkgParser_parsePackageMtd = pkgParserCls.getDeclaredMethod("parsePackage",

28                     typeArgs);

29             valueArgs = 

new Object[4];

30             valueArgs[0] = 

new File(apkPath);

31             valueArgs[1] = apkPath;

32             valueArgs[2] = metrics;

33             valueArgs[3] = PackageManager.GET_SIGNATURES;

34             Object pkgParserPkg = pkgParser_parsePackageMtd.invoke(pkgParser, valueArgs);

35             

36             typeArgs = 

new Class[2];

37             typeArgs[0] = pkgParserPkg.getClass();

38             typeArgs[1] = Integer.TYPE;

39             Method pkgParser_collectCertificatesMtd = pkgParserCls.getDeclaredMethod("collectCertificates",

40                     typeArgs);

41             valueArgs = 

new Object[2];

42             valueArgs[0] = pkgParserPkg;

43             valueArgs[1] = PackageManager.GET_SIGNATURES;

44             pkgParser_collectCertificatesMtd.invoke(pkgParser, valueArgs);

45             

//

 应用程序信息包, 这个公开的, 不过有些函数, 变量没公开

46 

            Field packageInfoFld = pkgParserPkg.getClass().getDeclaredField("mSignatures");

47             Signature[] info = (Signature[]) packageInfoFld.get(pkgParserPkg);

48             MediaApplication.logD(DownloadApk.

class, "size:"+info.length);

49             MediaApplication.logD(DownloadApk.

class, info[0].toCharsString());

50             

return info[0].toCharsString();

51         } 

catch (Exception e) {

52             e.printStackTrace();

53         }

54         

return 

null;

55     }

 

获取程序自身的签名：

private String getSign(Context context) {

        PackageManager pm = context.getPackageManager();

        List<PackageInfo> apps = pm.getInstalledPackages(PackageManager.GET_SIGNATURES);

        Iterator<PackageInfo> iter = apps.iterator();

        while(iter.hasNext()) {

             PackageInfo packageinfo = iter.next();

             String packageName = packageinfo.packageName;

             if (packageName.equals(instance.getPackageName())) {

                MediaApplication.logD(DownloadApk.class, packageinfo.signatures[0].toCharsString());

                return packageinfo.signatures[0].toCharsString();

             }

     }

        return null;

    }

 

对比2个方法的返回值来判断APK升级包的签名是否一致，一致就提示可以安装。