package com.pixplicity.workshop.beginners.listviews;

import android.app.ListActivity;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.widget.ListView;

public class CustomAdapterActivity extends ListActivity {

    private CustomAdapter mCustomAdapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        mCustomAdapter = new CustomAdapter(this);
        getListView().setAdapter(mCustomAdapter);
    }

    @Override
    protected void onListItemClick(ListView l, View v, int position, long id) {
        // TODO Complete the `onListItemClick` method. Use the `position` to retrieve an `Animal` object from the `mCustomerAdapter` field and use the `animal.infoUrl` information to create a valid `Uri`
        Uri uri = null;
        Intent intent = new Intent(Intent.ACTION_VIEW, uri);
        startActivity(intent);
    }

}
package com.pixplicity.workshop.beginners.listviews;

import android.app.ListActivity;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.widget.ListView;

public class CustomAdapterActivity extends ListActivity {

    private CustomAdapter mCustomAdapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        mCustomAdapter = new CustomAdapter(this);
        getListView().setAdapter(mCustomAdapter);
    }

    @Override
    protected void onListItemClick(ListView l, View v, int position, long id) {
        // TODO Exercise 04.03
        Uri uri = null;
        Intent intent = new Intent(Intent.ACTION_VIEW, uri);
        startActivity(intent);
    }

}

Update CustomAdapterActivity.java