我试图在android studio中使用firebase从Youtube tutorial构建一个简单的博客应用程序一切都很好但是当我添加一个类 SimpleBlog 时，从那时我运行我的应用程序继续崩溃。
错误信息是：
11-05 17:32:35.525 2485-2485/naim.google.com.photographyblog E/UncaughtException: java.lang.NoClassDefFoundError: Failed resolution of: Lcom/squareup/okhttp/OkHttpClient;
at com.squareup.picasso.OkHttpDownloader.defaultOkHttpClient(OkHttpDownloader.java:31)
at com.squareup.picasso.OkHttpDownloader.<init>(OkHttpDownloader.java:76)
at com.squareup.picasso.OkHttpDownloader.<init>(OkHttpDownloader.java:65)
at naim.google.com.photographyblog.SimpleBlog.onCreate(SimpleBlog.java:22)
at android.app.Instrumentation.callApplicationOnCreate(Instrumentation.java:1024)
at android.app.ActivityThread.handleBindApplication(ActivityThread.java:5361)
at android.app.ActivityThread.-wrap2(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1528)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6077)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:866)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:756)
Caused by: java.lang.ClassNotFoundException: Didn't find class "com.squareup.okhttp.OkHttpClient" on path: DexPathList[[zip file "/data/app/naim.google.com.photographyblog-1/base.apk", zip file "/data/app/naim.google.com.photographyblog-1/split_lib_dependencies_apk.apk", zip file "/data/app/naim.google.com.photographyblog-1/split_lib_slice_0_apk.apk", zip file "/data/app/naim.google.com.photographyblog-1/split_lib_slice_1_apk.apk", zip file "/data/app/naim.google.com.photographyblog-1/split_lib_slice_2_apk.apk", zip file "/data/app/naim.google.com.photographyblog-1/split_lib_slice_3_apk.apk", zip file "/data/app/naim.google.com.photographyblog-1/split_lib_slice_4_apk.apk", zip file "/data/app/naim.google.com.photographyblog-1/split_lib_slice_5_apk.apk", zip file "/data/app/naim.google.com.photographyblog-1/split_lib_slice_6_apk.apk", zip file "/data/app/naim.google.com.photographyblog-1/split_lib_slice_7_apk.apk", zip file "/data/app/naim.google.com.photographyblog-1/split_lib_slice_8_apk.apk", zip file "/data/app/naim.google.com.photographyblog-1/split_lib_slice_9_apk.apk"],nativeLibraryDirectories=[/data/app/naim.google.com.photographyblog-1/lib/x86, /system/lib, /vendor/lib]]
at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
at java.lang.ClassLoader.loadClass(ClassLoader.java:380)
at java.lang.ClassLoader.loadClass(ClassLoader.java:312)
at com.squareup.picasso.OkHttpDownloader.defaultOkHttpClient(OkHttpDownloader.java:31)
at com.squareup.picasso.OkHttpDownloader.<init>(OkHttpDownloader.java:76)
at com.squareup.picasso.OkHttpDownloader.<init>(OkHttpDownloader.java:65)
at naim.google.com.photographyblog.SimpleBlog.onCreate(SimpleBlog.java:22)
at android.app.Instrumentation.callApplicationOnCreate(Instrumentation.java:1024)
at android.app.ActivityThread.handleBindApplication(ActivityThread.java:5361)
at android.app.ActivityThread.-wrap2(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1528)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6077)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:866)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:756)
11-05 17:32:36.753 2485-2485/naim.google.com.photographyblog E/AndroidRuntime: FATAL EXCEPTION: main
Process: naim.google.com.photographyblog, PID: 2485
java.lang.NoClassDefFoundError: Failed resolution of: Lcom/squareup/okhttp/OkHttpClient;
at com.squareup.picasso.OkHttpDownloader.defaultOkHttpClient(OkHttpDownloader.java:31)
at com.squareup.picasso.OkHttpDownloader.<init>(OkHttpDownloader.java:76)
at com.squareup.picasso.OkHttpDownloader.<init>(OkHttpDownloader.java:65)
at naim.google.com.photographyblog.SimpleBlog.onCreate(SimpleBlog.java:22)
at android.app.Instrumentation.callApplicationOnCreate(Instrumentation.java:1024)
at android.app.ActivityThread.handleBindApplication(ActivityThread.java:5361)
at android.app.ActivityThread.-wrap2(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1528)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6077)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:866)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:756)
Caused by: java.lang.ClassNotFoundException: Didn't find class "com.squareup.okhttp.OkHttpClient" on path: DexPathList[[zip file "/data/app/naim.google.com.photographyblog-1/base.apk", zip file "/data/app/naim.google.com.photographyblog-1/split_lib_dependencies_apk.apk", zip file "/data/app/naim.google.com.photographyblog-1/split_lib_slice_0_apk.apk", zip file "/data/app/naim.google.com.photographyblog-1/split_lib_slice_1_apk.apk", zip file "/data/app/naim.google.com.photographyblog-1/split_lib_slice_2_apk.apk", zip file "/data/app/naim.google.com.photographyblog-1/split_lib_slice_3_apk.apk", zip file "/data/app/naim.google.com.photographyblog-1/split_lib_slice_4_apk.apk", zip file "/data/app/naim.google.com.photographyblog-1/split_lib_slice_5_apk.apk", zip file "/data/app/naim.google.com.photographyblog-1/split_lib_slice_6_apk.apk", zip file "/data/app/naim.google.com.photographyblog-1/split_lib_slice_7_apk.apk", zip file "/data/app/naim.google.com.photographyblog-1/split_lib_slice_8_apk.apk", zip file "/data/app/naim.google.com.photographyblog-1/split_lib_slice_9_apk.apk"],nativeLibraryDirectories=[/data/app/naim.google.com.photographyblog-1/lib/x86, /system/lib, /vendor/lib]]
at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
at java.lang.ClassLoader.loadClass(ClassLoader.java:380)
at java.lang.ClassLoader.loadClass(ClassLoader.java:312)
at com.squareup.picasso.OkHttpDownloader.defaultOkHttpClient(OkHttpDownloader.java:31)
at com.squareup.picasso.OkHttpDownloader.<init>(OkHttpDownloader.java:76)
at com.squareup.picasso.OkHttpDownloader.<init>(OkHttpDownloader.java:65)
at naim.google.com.photographyblog.SimpleBlog.onCreate(SimpleBlog.java:22)
at android.app.Instrumentation.callApplicationOnCreate(Instrumentation.java:1024)
at android.app.ActivityThread.handleBindApplication(ActivityThread.java:5361)
at android.app.ActivityThread.-wrap2(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1528)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6077)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:866)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:756)
这是我的 build.gradle
apply plugin: 'com.android.application'
android {
compileSdkVersion 26
defaultConfig {
applicationId "naim.google.com.photographyblog"
minSdkVersion 15
targetSdkVersion 26
versionCode 1
versionName "1.0"
multiDexEnabled true
testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
}
dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation 'com.android.support:appcompat-v7:26.1.0'
implementation 'com.android.support:recyclerview-v7:26.1.0'
implementation 'com.android.support:cardview-v7:26.1.0'
implementation 'com.android.support.constraint:constraint-layout:1.0.2'
implementation 'com.google.firebase:firebase-auth:11.0.4'
implementation 'com.google.firebase:firebase-database:11.0.4'
implementation 'com.google.firebase:firebase-storage:11.0.4'
implementation 'com.google.android.gms:play-services:11.0.4'
implementation 'com.firebaseui:firebase-ui-database:2.3.0'
implementation 'com.squareup.picasso:picasso:2.5.2'
implementation 'com.squareup.okhttp3:okhttp:2.4.0'
implementation 'com.jakewharton.picasso:picasso2-okhttp3-downloader:1.0.2'
implementation 'com.android.support:multidex:1.0.1'
testImplementation 'junit:junit:4.12'
androidTestImplementation 'com.android.support.test:runner:1.0.1'
androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.1'
}
apply plugin: 'com.google.gms.google-services'
这是我的 SimpleBlog.java 文件：
package naim.google.com.photographyblog;
import android.app.Application;
import com.google.firebase.database.FirebaseDatabase;
import com.squareup.picasso.OkHttpDownloader;
import com.squareup.picasso.Picasso;
/**
* Created by bd on 11/5/2017.
*/
public class SimpleBlog extends Application {
@Override
public void onCreate() {
super.onCreate();
FirebaseDatabase.getInstance().setPersistenceEnabled(true);
Picasso.Builder builder = new Picasso.Builder(this);
builder.downloader(new OkHttpDownloader(this,Integer.MAX_VALUE));
Picasso built = builder.build();
built.setIndicatorsEnabled(false);
built.setLoggingEnabled(true);
Picasso.setSingletonInstance(built);
}
}
我认为问题出在我的主要活动中，所以这是我的 MainActivity.java 文件：
package naim.google.com.photographyblog;
import android.content.Context;
import android.content.Intent;
import android.support.annotation.NonNull;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;
import com.firebase.ui.database.FirebaseRecyclerAdapter;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.ValueEventListener;
import com.squareup.picasso.Picasso;
public class MainActivity extends AppCompatActivity {
private RecyclerView mBlogList;
private DatabaseReference mDatabase;
private DatabaseReference mDatabaseUsers;
private FirebaseAuth mAuth;
private FirebaseAuth.AuthStateListener mAuthListner;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mAuth = FirebaseAuth.getInstance();
mAuthListner = new FirebaseAuth.AuthStateListener() {
@Override
public void onAuthStateChanged(@NonNull FirebaseAuth firebaseAuth) {
if(firebaseAuth.getCurrentUser() == null)
{
Intent intent = new Intent(MainActivity.this , LoginActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(intent);
}
}
};
mDatabase = FirebaseDatabase.getInstance().getReference().child("Blog");
mDatabaseUsers = FirebaseDatabase.getInstance().getReference().child("Users");
mDatabase.keepSynced(true);
mDatabaseUsers.keepSynced(true);
mBlogList = findViewById(R.id.blog_list);
LinearLayoutManager layoutManager = new LinearLayoutManager(this);
layoutManager.setReverseLayout(true);
layoutManager.setStackFromEnd(true);
mBlogList.setHasFixedSize(true);
mBlogList.setLayoutManager(layoutManager);
}
@Override
protected void onStart() {
super.onStart();
mAuth.addAuthStateListener(mAuthListner);
FirebaseRecyclerAdapter<Blog , BlogViewHolder> firebaseRecyclerAdapter = new FirebaseRecyclerAdapter<Blog, BlogViewHolder>(
Blog.class,
R.layout.blog_row,
BlogViewHolder.class,
mDatabase
) {
@Override
protected void populateViewHolder(BlogViewHolder viewHolder, Blog model, int position) {
viewHolder.setTitle(model.getTitle());
viewHolder.setDescription(model.getDescription());
viewHolder.setImage(getApplicationContext() , model.getImage());
}
};
mBlogList.setAdapter(firebaseRecyclerAdapter);
}
private void checkUserExist()
{
if(mAuth.getCurrentUser()!=null)
{
final String user_id = mAuth.getCurrentUser().getUid();
mDatabaseUsers.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
if(!dataSnapshot.hasChild(user_id)){
Intent intent = new Intent(MainActivity.this , SetupActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(intent);
}
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
}
public static class BlogViewHolder extends RecyclerView.ViewHolder{
View mView;
public BlogViewHolder(View itemView) {
super(itemView);
mView = itemView;
}
public void setTitle(String title){
TextView post_title = mView.findViewById(R.id.post_title);
post_title.setText(title);
}
public void setDescription(String description){
TextView post_description = mView.findViewById(R.id.post_description);
post_description.setText(description);
}
public void setImage(Context ctx ,String image) {
ImageView post_image = mView.findViewById(R.id.post_image);
Picasso.with(ctx).load(image).into(post_image);
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main_menu,menu);
return super.onCreateOptionsMenu(menu);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
if(item.getItemId()==R.id.action_add)
{
startActivity(new Intent(MainActivity.this,PostActivity.class));
}
if(item.getItemId() == R.id.action_logout)
{
logout();
}
return super.onOptionsItemSelected(item);
}
private void logout()
{
mAuth.signOut();
}
}