diff --git a/build.gradle b/build.gradle
index cd74ded..b4148ef 100644
--- a/build.gradle
+++ b/build.gradle
@@ -3,9 +3,10 @@
 buildscript {
     repositories {
         jcenter()
+        google()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:1.2.3'
+        classpath 'com.android.tools.build:gradle:3.2.0'
     }
 }
 
@@ -15,5 +16,6 @@ allprojects {
 
     repositories {
         jcenter()
+        google()
     }
 }
\ No newline at end of file
diff --git a/demo/build.gradle b/demo/build.gradle
index 8b3ed8d..20044ae 100644
--- a/demo/build.gradle
+++ b/demo/build.gradle
@@ -1,12 +1,12 @@
 apply plugin: 'com.android.application'
 
 android {
-    compileSdkVersion 21
-    buildToolsVersion '21.1.1'
+    compileSdkVersion 30
+    buildToolsVersion '21.1.2'
     defaultConfig {
         applicationId 'me.gujun.android.taggroup.demo'
-        minSdkVersion 8
-        targetSdkVersion 21
+        minSdkVersion 14
+        targetSdkVersion 30
         versionName project.VERSION_NAME
         versionCode Integer.parseInt(project.VERSION_CODE)
     }
@@ -22,5 +22,5 @@ android {
 
 dependencies {
     compile project(':library')
-    compile 'com.android.support:appcompat-v7:21.0.3'
+    compile 'androidx.appcompat:appcompat:1.3.1'
 }
\ No newline at end of file
diff --git a/demo/src/main/java/me/gujun/android/taggroup/demo/MainActivity.java b/demo/src/main/java/me/gujun/android/taggroup/demo/MainActivity.java
index 872bf9f..958c66a 100644
--- a/demo/src/main/java/me/gujun/android/taggroup/demo/MainActivity.java
+++ b/demo/src/main/java/me/gujun/android/taggroup/demo/MainActivity.java
@@ -2,7 +2,8 @@
 
 import android.content.Intent;
 import android.os.Bundle;
-import android.support.v7.app.ActionBarActivity;
+import androidx.appcompat.app.AppCompatActivity;
+
 import android.view.Menu;
 import android.view.MenuItem;
 import android.view.View;
@@ -13,7 +14,7 @@
 import me.gujun.android.taggroup.demo.db.TagsManager;
 
 
-public class MainActivity extends ActionBarActivity {
+public class MainActivity extends AppCompatActivity {
     private TextView mPromptText;
 
     private TagGroup mDefaultTagGroup;
@@ -38,7 +39,7 @@ protected void onCreate(Bundle savedInstanceState) {
         mTagsManager = TagsManager.getInstance(getApplicationContext());
         String[] tags = mTagsManager.getTags();
 
-        mPromptText = (TextView) findViewById(R.id.tv_prompt);
+        mPromptText = findViewById(R.id.tv_prompt);
         mPromptText.setVisibility((tags == null || tags.length == 0) ? View.VISIBLE : View.GONE);
         mPromptText.setOnClickListener(new View.OnClickListener() {
             @Override
@@ -47,11 +48,11 @@ public void onClick(View v) {
             }
         });
 
-        mDefaultTagGroup = (TagGroup) findViewById(R.id.tag_group);
-        mSmallTagGroup = (TagGroup) findViewById(R.id.tag_group_small);
-        mLargeTagGroup = (TagGroup) findViewById(R.id.tag_group_large);
-        mBeautyTagGroup = (TagGroup) findViewById(R.id.tag_group_beauty);
-        mBeautyInverseTagGroup = (TagGroup) findViewById(R.id.tag_group_beauty_inverse);
+        mDefaultTagGroup = findViewById(R.id.tag_group);
+        mSmallTagGroup = findViewById(R.id.tag_group_small);
+        mLargeTagGroup = findViewById(R.id.tag_group_large);
+        mBeautyTagGroup = findViewById(R.id.tag_group_beauty);
+        mBeautyInverseTagGroup = findViewById(R.id.tag_group_beauty_inverse);
         if (tags != null && tags.length > 0) {
             mDefaultTagGroup.setTags(tags);
             mSmallTagGroup.setTags(tags);
diff --git a/demo/src/main/java/me/gujun/android/taggroup/demo/TagEditorActivity.java b/demo/src/main/java/me/gujun/android/taggroup/demo/TagEditorActivity.java
index 27d2ea1..50d363d 100644
--- a/demo/src/main/java/me/gujun/android/taggroup/demo/TagEditorActivity.java
+++ b/demo/src/main/java/me/gujun/android/taggroup/demo/TagEditorActivity.java
@@ -1,7 +1,8 @@
 package me.gujun.android.taggroup.demo;
 
 import android.os.Bundle;
-import android.support.v7.app.ActionBarActivity;
+import androidx.appcompat.app.AppCompatActivity;
+
 import android.view.Menu;
 import android.view.MenuItem;
 
@@ -9,7 +10,7 @@
 import me.gujun.android.taggroup.demo.db.TagsManager;
 
 
-public class TagEditorActivity extends ActionBarActivity {
+public class TagEditorActivity extends AppCompatActivity {
     private TagGroup mTagGroup;
     private TagsManager mTagsManager;
 
@@ -21,7 +22,7 @@ protected void onCreate(Bundle savedInstanceState) {
         mTagsManager = TagsManager.getInstance(getApplicationContext());
         String[] tags = mTagsManager.getTags();
 
-        mTagGroup = (TagGroup) findViewById(R.id.tag_group);
+        mTagGroup = findViewById(R.id.tag_group);
         mTagGroup.setTags(tags);
     }
 
diff --git a/gradle.properties b/gradle.properties
index e61bff9..1d0cf87 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -33,4 +33,6 @@ POM_DEVELOPER_ID=2dxgujun
 POM_DEVELOPER_NAME=Jun Gu
 
 SNAPSHOT_REPOSITORY_URL=https://oss.sonatype.org/content/repositories/snapshots
-RELEASE_REPOSITORY_URL=https://oss.sonatype.org/service/local/staging/deploy/maven2
\ No newline at end of file
+RELEASE_REPOSITORY_URL=https://oss.sonatype.org/service/local/staging/deploy/maven2
+android.useAndroidX=true
+android.enableJetifier=true
\ No newline at end of file
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index 0c71e76..ae99105 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,6 @@
-#Wed Apr 10 15:27:10 PDT 2013
+#Tue Aug 17 23:21:38 BDT 2021
 distributionBase=GRADLE_USER_HOME
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.8.1-bin.zip
 distributionPath=wrapper/dists
-zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-2.2.1-all.zip
+zipStoreBase=GRADLE_USER_HOME
diff --git a/library/build.gradle b/library/build.gradle
index 87bfd43..d295a57 100644
--- a/library/build.gradle
+++ b/library/build.gradle
@@ -1,10 +1,10 @@
 apply plugin: 'com.android.library'
 android {
-    compileSdkVersion 21
-    buildToolsVersion '21.1.1'
+    compileSdkVersion 30
+    buildToolsVersion '21.1.2'
     defaultConfig {
         minSdkVersion 8
-        targetSdkVersion 21
+        targetSdkVersion 30
     }
     lintOptions {
         abortOnError false