MainActivity.java

package com.example.pradeepkumar.adpost;

import android.content.Context;
import android.content.Intent;
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 com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.squareup.picasso.Picasso;
import com.firebase.ui.database.FirebaseRecyclerAdapter;

public class MainActivity extends AppCompatActivity {
    private RecyclerView mBlogList;
    private DatabaseReference mDatabase;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mDatabase= FirebaseDatabase.getInstance().getReference().child("PMIT");
        mBlogList=(RecyclerView)findViewById(R.id.blog_list);
        mBlogList.setHasFixedSize(true);
        mBlogList.setLayoutManager(new LinearLayoutManager(this));

    }

    @Override
    protected void onStart() {
        super.onStart();
        FirebaseRecyclerAdapter<Blog,BlogViewHolder> firebaseRecyclerAdapter=new FirebaseRecyclerAdapter<Blog,BlogViewHolder>(
                Blog.class,
                R.layout.blog_row,
                BlogViewHolder.class,mDatabase

        ){
            protected void populateViewHolder(BlogViewHolder viewHolder,Blog model,int position){
                viewHolder.setTitle(model.getTitle());
                viewHolder.setDesc(model.getDesc());
                viewHolder.setImage(getApplicationContext(),model.getImage());
            }
        };
        mBlogList.setAdapter(firebaseRecyclerAdapter);
    }

    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=(TextView) mView.findViewById(R.id.post_title);
            post_title.setText(title);
        }
        public void setDesc(String desc){
            TextView post_desc=(TextView)mView.findViewById(R.id.post_desc);
            post_desc.setText(desc);
        }
        public void setImage(Context ctx,String image){
            ImageView post_image=(ImageView)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_post){
            startActivity(new Intent(MainActivity.this,PostActivity.class));
        }
        return super.onOptionsItemSelected(item);
    }
}