Issue in resolving nonnull and notnull symbol in l

问题:

I'm developing an android app please help me to solve dependency error.

package android.os;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;

I've add following dependencies:

dependencies {

    compile group: 'com.google.code.findbugs', name: 'jsr305', version: '3.0.0'
    compile 'com.android.support:multidex:1.0.1'
    compile fileTree(include: ['*.jar'], dir: 'libs')
    testCompile 'junit:junit:4.12'
    compile 'com.android.support:appcompat-v7:23.1.1'
    compile 'com.android.support:support-v4:23.1.1'
    compile 'com.android.support:design:23.1.1'
    compile 'com.parse:parse-android:1.12.0'
    compile fileTree(include: '*.jar', dir: 'libs')
    compile 'com.squareup.picasso:picasso:2.5.2'
    compile 'com.android.support:support-annotations:23.1.1'
}

回答1:

Add following in your dependencies

compile 'com.android.support:support-annotations:+'

Also, verify this

Go to File -> Setting -> search for "nullable" and verify these settings.

回答2:

Add following in your dependencies

dependencies {
    compile 'com.android.support:support-annotations:+'
}

回答3:

Since Google announced at IO17 gradle:3.0, the compile configuration is now deprecated and should be replaced by implementation or api

So prefer

dependencies {
    ...
    implementation 'com.android.support:support-annotations:27.1.1'
    ...
}

or greater version

回答4:

try to import android.support.annotation.NonNull; also add gradle build as other guys already mentioned:

dependencies {
        compile 'com.android.support:support-annotations:+'
    }