Using JSON to retrieve and display images from Tumblr

Question

so i'm completely clueless here on the subject of retrieving, displaying and such using an API. I've already gotten a JSON URL with all the parameters setup and such but I don't know how to express this in an Android application. I used jsongen.com to format everything and parse the JSON into java objects but am clueless from that point on.

Java Code:

package com.android.tumblr.api;

import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ImageView;

public class MainActivity extends Activity {

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

    try {
          ImageView image = (ImageView)findViewById(R.id.tvImage);
          Bitmap bitmap = BitmapFactory.decodeStream((InputStream)
new URL("https://pbs.twimg.com/profile_images/423147305605554176/EYnBh68.jpeg")
.getContent());
          image.setImageBitmap(bitmap); 


        } catch (MalformedURLException e) {
          e.printStackTrace();
        } catch (IOException e) {
          e.printStackTrace();
        }

}
}

XML code of the Layout

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
   xmlns:tools="http://schemas.android.com/tools"
   android:layout_width="match_parent"
   android:layout_height="match_parent"
   tools:context="${packageName}.${activityClass}" >

<ImageView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/tvImage" 
    android:minHeight="50dp"
    android:minWidth="50dp"/>

</RelativeLayout>

XML code of manifest

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.android.tumblr.api"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-permission android:name="android.permission.INTERNET" /> 
    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="19" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.android.tumblr.api.MainActivity"
            android:label="@string/title_activity_main" >
        </activity>
    </application>

</manifest>

You need to be more specific. It is not clear from your original post what is it that you trying to solve. How to fire request to fetch JSON, how to handle retrieval of JSON or how to fetch actual images??? — peter_budo, May 27 '14 at 13:48

score 2 · Answer 1 · edited May 23 '17 at 11:57

2

You need to implement JSON parser and should consider implementing cache manager for better performance.

For the implementation of the Json parser you have a lot of alternatives but according to my experience - Gson and JsonParser are the best.

Gson provide you the ability to auto create json from java entity or java entity from the gson. Here you can find a good example for gson parsing, and from here you can download the library.

A good open source cache manager you can find here - bitmapFun, volley, picasso

If you don't want to add cache manager you can simply download the image and execute:

ImageView imageView = (ImageView)findViewById(R.id.image_view);
imageView.setBitmap(bitmap);

you can find here code that streaming image into bitmap

edited May 23 '17 at 11:57

Community

1
1

answered May 27 '14 at 13:39

Nativ

3,092
6
38
69

But that's my problem. How do I get the ImageView to recognize the image from a JSON link? – Victor Strandmoe May 27 '14 at 16:37
First of all you need to create a bitmap, into that bitmap you need to stream the image's bytes from the link( you can use the decoder from the last link I sent you), after you have the bitmap execute the two lines of code from above. – Nativ May 28 '14 at 08:41
I edited my code and did what you said. Yet it still doesn't work – Victor Strandmoe May 28 '14 at 08:53
Can you post your code in order for us to help you? – Nativ May 28 '14 at 08:56
I did so. Please check it out :) – Victor Strandmoe May 28 '14 at 09:02
It's giving me an error : "Failed to install TumblrAPITest.apk on device 'emulator-5554!" – Victor Strandmoe May 28 '14 at 09:03
@Victor Strandmoe it isn't a problem in loading the image from link to ImageView, it's a problem that you can't install the apk on your emulator. This is a totally different thread. Check that your emulator's OS version is at least the minSdkVersion from your manifest or try to load it on a real device. – Nativ May 28 '14 at 09:09
Well i know that isn't the problem because even when I try to run it o a physical device using an AppInstaller it doesn't open at all. I'm sure it's the code :/ – Victor Strandmoe May 28 '14 at 10:57
It is something with the installation of the apk, try to go through your project configuration or recreate the project(New -> Android project). – Nativ May 28 '14 at 11:14
Are you sure there is nothing wrong in my code? would you mind trying and running that and see if it works on your device(s)? – Victor Strandmoe May 28 '14 at 20:16
Yes the error that you wrote here is making it pretty clear, moreover, if you had something wrong with your code than you would had a better log to show me, something like NullPointerException, ClassCastException, etc – Nativ May 29 '14 at 08:38

score 0 · Answer 2 · answered May 27 '14 at 11:22

0

Try using Retrofit library for implementing REST client. And Picasso is good enough for displaying images from URL into ImageView

answered May 27 '14 at 11:22

Tishka17

305
2
12

Using JSON to retrieve and display images from Tumblr

2 Answers2