Google Drive Api v3 and proguard

问题

After shrinking my release apk with proguard files().list() returns no files (in debug mode it does). I used the quickstart sample for login. There are no error messages. Login seems to be successful.

Here is my proguard.cfg:

-optimizationpasses 1
#-dontoptimize
-dontusemixedcaseclassnames
-dontskipnonpubliclibraryclasses
-dontpreverify
-verbose
-optimizations !code/simplification/arithmetic,!field/*,!class/merging/*,!class/unboxing/enum
-dontwarn android.support.v4.**
-dontwarn com.google.**
#-keep public class com.google.**
#-keep public class android.**
#-keep class com.google.android.gms.** { *; }
-keepattributes Signature,RuntimeVisibleAnnotations,AnnotationDefault

#-keep public class * extends android.app.Activity
#-keep public class * extends android.app.Application
-keep public class * extends android.app.Service
-keep public class * extends android.content.BroadcastReceiver
-keep public class * extends android.content.ContentProvider
-keep public class * extends android.app.backup.BackupAgentHelper
-keep public class * extends android.preference.Preference
-keep public class com.android.vending.licensing.ILicensingService


#-keep public class pub.devrel.easypermissions.**


-keepclasseswithmembernames class * {
    native <methods>;
}

-keepclasseswithmembers class * {
    public <init>(android.content.Context, android.util.AttributeSet);
}

-keepclasseswithmembers class * {
    public <init>(android.content.Context, android.util.AttributeSet, int);
}

-keepclassmembers class * extends android.app.Activity {
   public void *(android.view.View);
}


-keepclassmembers enum * {
    public static **[] values();
    public static ** valueOf(java.lang.String);
}

-keep class * implements android.os.Parcelable {
  public static final android.os.Parcelable$Creator *;
}

This is the Code for retrieving the files:

private List<String> getDataFromApi() throws Exception {
            // Get a list of up to 10 files.
            lib.setgstatus("getDataFromApi Start");
            List<String> fileInfo = new ArrayList<String>();
            FileList result = mService.files().list()
                    .setPageSize(10)
                    .setFields("nextPageToken, files(id, name)")
                    .execute();
            lib.setgstatus(result.toString());
            List<File> files = result.getFiles();

            if (files != null) {
                lib.setgstatus("getDataFromApi files.size:" + files.size());
                for (File file : files) {
                    fileInfo.add(String.format("%s (%s)\n",
                            file.getName(), file.getId()));
                }
            }
            else
            {
                lib.setgstatus("getDataFromApi files is null");
            }

            lib.setgstatus("getDataFromApi Finish");
            return fileInfo;
        }

result.toString() Returns a valid JSON result, but files is null.

This is my build.gradle:

apply plugin: 'com.android.application'

    android {
    compileSdkVersion 24
    buildToolsVersion "24.0.3"

    defaultConfig {
        applicationId "org.de.jmg.jmgphotouploader"
        minSdkVersion 11
        targetSdkVersion 24
    }
    signingConfigs {
        release {
            keyAlias 'jmgphotouploader'
            keyPassword '****'
            storeFile file('/pub/keystore')
            storePassword '****'
        }
        debug {
            keyAlias 'jmgphotouploader'
            keyPassword '****'
            storeFile file('/pub/keystore')
            storePassword '****'
        }
    }

    buildTypes {
        debug {
            debuggable true
            minifyEnabled false
            //shrinkResources true
            //proguardFile 'proguard.cfg'
        }
        release {
            debuggable false
            minifyEnabled true
            shrinkResources true
            proguardFile 'proguard.cfg'
            //proguardFile getDefaultProguardFile('proguard-android.txt')
            //proguardFiles getDefaultProguardFile('proguard-android.txt') ,'proguard.cfg'
        }
    }
}
dependencies {
    compile 'com.android.support:appcompat-v7:24.2.1'
    compile 'com.android.support:support-v4:24.2.1'
    compile project(':src')
    compile project(':utilities')
    compile 'com.google.android.gms:play-services-auth:9.6.1'
    compile 'pub.devrel:easypermissions:0.1.5'
    compile('com.google.api-client:google-api-client-android:1.22.0') {
        exclude group: 'org.apache.httpcomponents'
        }
    compile('com.google.apis:google-api-services-drive:v3-rev47-1.22.0') {
        exclude group: 'org.apache.httpcomponents'
        }

}

回答1:

Adding just

-keep class * extends com.google.api.client.json.GenericJson {
*;
}
-keep class com.google.api.services.drive.** {
*;
}

to proguard.cfg works!

回答2:

Check on this related issue.

Any chance Proguard kicks in when exporting your signed APK? If you rely on i.e. variable names to map the JSON onto POJOs, this is likely to brake without the appropriate Proguard exclusions/rules. Have a look in your project.properties file and comment out any lines in the form of proguard.config=<file_name>. After that, export another signed APK and retest.

Make sure that you add minifyEnabled true to the appropriate build type in your build.gradle file to enable code shrinking with ProGuard as stated on this documentation.

来源：https://stackoverflow.com/questions/40289822/google-drive-api-v3-and-proguard