Java 从Tumblr解析JSONObject_Java_Android_Json_Parsing_Tumblr

Java 从Tumblr解析JSONObject

java android json parsing

Java 从Tumblr解析JSONObject,java,android,json,parsing,tumblr,Java,Android,Json,Parsing,Tumblr,我试图教自己制作android应用程序，因此我试图创建一个应用程序，在列表视图中显示tumblr帐户中的图像我在解析JSONObject时遇到一些问题，我的应用程序因为nullPointerException而崩溃我的代码如下所示： public class Example extends Activity { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstan

我试图教自己制作android应用程序，因此我试图创建一个应用程序，在列表视图中显示tumblr帐户中的图像

我在解析JSONObject时遇到一些问题，我的应用程序因为nullPointerException而崩溃

我的代码如下所示：

public class Example extends Activity {

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    ArrayList<Tweet> tweets;
    try {
        tweets = getTweets();
        ListView listView = (ListView) findViewById(R.id.ListViewId);
        listView.setAdapter(new UserItemAdapter(this, R.layout.listitem,
                tweets));
    } catch (ClientProtocolException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (JSONException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

}

public class UserItemAdapter extends ArrayAdapter<Tweet> {
    private ArrayList<Tweet> tweets;

    public UserItemAdapter(Context context, int imageViewResourceId,
            ArrayList<Tweet> tweets) {
        super(context, imageViewResourceId, tweets);
        this.tweets = tweets;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        View v = convertView;
        if (v == null) {
            LayoutInflater vi = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            v = vi.inflate(R.layout.listitem, null);
        }

        Tweet tweet = tweets.get(position);
        if (tweet != null) {

            ImageView image = (ImageView) v.findViewById(R.id.avatar);

            if (image != null) {
                image.setImageBitmap(getBitmap(tweet.image_url));
            }
        }
        return v;
    }
}

public Bitmap getBitmap(String bitmapUrl) {
    try {
        URL url = new URL(bitmapUrl);
        return BitmapFactory.decodeStream(url.openConnection()
                .getInputStream());
    } catch (Exception ex) {
        return null;
    }
}

public ArrayList<Tweet> getTweets() throws ClientProtocolException,
        IOException, JSONException {
    String searchUrl = "http://api.tumblr.com/v2/blog/www.richkidsofinstagram.tumblr.com/posts?api_key=API_KEY";

    ArrayList<Tweet> tweets = new ArrayList<Tweet>();

    HttpClient client = new DefaultHttpClient();
    HttpGet get = new HttpGet(searchUrl);

    ResponseHandler<String> responseHandler = new BasicResponseHandler();

    String responseBody = null;
    try {
        responseBody = client.execute(get, responseHandler);
    } catch (Exception ex) {
        ex.printStackTrace();
    }

    JSONObject jsonObject = new JSONObject(responseBody);

    JSONArray arr = null;

    try {
        arr = jsonObject.getJSONArray("results");
    } catch (Exception ex) {
        Log.v("TEST", "Exception: " + ex.getMessage());
    }

    for (int i = 0; i < arr.length(); i++) {
        Tweet tweet = new Tweet(arr.getJSONObject(i).getString("photos"));
        tweets.add(tweet);
    }

    return tweets;
}

public class Tweet {

    public String image_url;

    public Tweet(String url) {

        this.image_url = url;
    }
    }
    }

{
"meta": {
    "status": 200,
    "msg": "OK"
},
"response": {
    "blog": {
        "title": "Rich Kids Of Instagram",
        "posts": 154,
        "name": "richkidsofinstagram",
        "url": "http://richkidsofinstagram.tumblr.com/",
        "updated": 1346803265,
        "description": "They have more money than you and this is what they do.
        "ask": true,
        "ask_anon": true
    },
    "posts": [
        {
            "blog_name": "richkidsofinstagram",
            "id": 30900248446,
            "post_url":          "http://richkidsofinstagram.tumblr.com/post/30900248446/hamptons-are-good",
            "slug": "hamptons-are-good",
            "type": "photo",
            "date": "2012-09-04 23:58:45 GMT",
            "timestamp": 1346803125,
            "state": "published",
            "format": "html",
            "reblog_key": "2KosMjea",
            "tags": [
                "pool",
                "hamptons",
                "summer",
                "rich",
                "wealth"
            ],
            "highlighted": [],
            "note_count": 99,
            "caption": "<p><span>The Hamptons are…….. good. by matthewmorton</span></p>",
            "photos": [
                {
                    "caption": "",
                    "alt_sizes": [
                        {
                            "width": 500,
                            "height": 500,
                            "url": "http://24.media.tumblr.com/tumblr_m9uiqy9Mi71rb86ldo1_500.jpg"
                        },
                        {
                            "width": 400,
                            "height": 400,
                            "url": "http://25.media.tumblr.com/tumblr_m9uiqy9Mi71rb86ldo1_400.jpg"
                        },
                        {
                            "width": 250,
                            "height": 250,
                            "url": "http://25.media.tumblr.com/tumblr_m9uiqy9Mi71rb86ldo1_250.jpg"
                        },
                        {
                            "width": 100,
                            "height": 100,
                            "url": "http://25.media.tumblr.com/tumblr_m9uiqy9Mi71rb86ldo1_100.jpg"
                        },
                        {
                            "width": 75,
                            "height": 75,
                            "url": "http://25.media.tumblr.com/tumblr_m9uiqy9Mi71rb86ldo1_75sq.jpg"
                        }
                    ],
                    "original_size": {
                        "width": 500,
                        "height": 500,
                        "url": "http://24.media.tumblr.com/tumblr_m9uiqy9Mi71rb86ldo1_500.jpg"
                    }
                }
            ]
        },

公共类示例扩展活动{
@凌驾
创建时的公共void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（R.layout.main）；
ArrayList推文；
试一试{
tweets=getTweets（）；
ListView ListView=（ListView）findViewById（R.id.ListViewId）；
setAdapter（新的UserItemAdapter（这个，R.layout.listitem，
推特）；
}捕获（客户端协议例外e）{
//TODO自动生成的捕捉块
e、 printStackTrace（）；
}捕获（IOE异常）{
//TODO自动生成的捕捉块
e、 printStackTrace（）；
}捕获（JSONException e）{
//TODO自动生成的捕捉块
e、 printStackTrace（）；
}
}
公共类UserItemAdapter扩展了ArrayAdapter{
私人ArrayList推文；
公共UserItemAdapter（上下文上下文，int-imageViewResourceId，
ArrayList推文）{
超级（上下文、imageViewResourceId、tweets）；
this.tweets=tweets；
}
@凌驾
公共视图getView（int位置、视图转换视图、视图组父视图）{
视图v=转换视图；
如果（v==null）{
LayoutInflater vi=（LayoutInflater）getSystemService（Context.LAYOUT\u INFLATER\u SERVICE）；
v=vi.充气（R.layout.listitem，空）；
}
Tweet=tweets.get（位置）；
if（tweet！=null）{
ImageView图像=（ImageView）v.findViewById（R.id.avatar）；
如果（图像！=null）{
setImageBitmap（getBitmap（tweet.image_url））；
}
}
返回v；
}
}
公共位图getBitmap（字符串bitmapUrl）{
试一试{
URL URL=新URL（位图URL）；
返回BitmapFactory.decodeStream（url.openConnection（）
.getInputStream（））；
}捕获（例外情况除外）{
返回null；
}
}
public ArrayList getTweets（）抛出ClientProtocolException，
IOException，jsoneexception{
字符串搜索URL=”http://api.tumblr.com/v2/blog/www.richkidsofinstagram.tumblr.com/posts?api_key=API_KEY";
ArrayList tweets=新建ArrayList（）；
HttpClient=new DefaultHttpClient（）；
HttpGet=newhttpget（searchUrl）；
ResponseHandler ResponseHandler=新BasicResponseHandler（）；
字符串responseBody=null；
试一试{
responseBody=client.execute（get，responseHandler）；
}捕获（例外情况除外）{
例如printStackTrace（）；
}
JSONObject JSONObject=新的JSONObject（ResponseBy）；
JSONArray arr=null；
试一试{
arr=jsonObject.getJSONArray（“结果”）；
}捕获（例外情况除外）{
Log.v（“测试”，“异常：+ex.getMessage（））；
}
对于（int i=0；i


nullPointerException发生在第124行：
  for (int i = 0; i < arr.length(); i++) {
        Tweet tweet = new Tweet(arr.getJSONObject(i).getString("photos"));
        tweets.add(tweet);
    }

for（int i=0；i

我还通过www.jsonlint.com验证了地址，JSON如下所示：
public class Example extends Activity {

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    ArrayList<Tweet> tweets;
    try {
        tweets = getTweets();
        ListView listView = (ListView) findViewById(R.id.ListViewId);
        listView.setAdapter(new UserItemAdapter(this, R.layout.listitem,
                tweets));
    } catch (ClientProtocolException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (JSONException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

}

public class UserItemAdapter extends ArrayAdapter<Tweet> {
    private ArrayList<Tweet> tweets;

    public UserItemAdapter(Context context, int imageViewResourceId,
            ArrayList<Tweet> tweets) {
        super(context, imageViewResourceId, tweets);
        this.tweets = tweets;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        View v = convertView;
        if (v == null) {
            LayoutInflater vi = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            v = vi.inflate(R.layout.listitem, null);
        }

        Tweet tweet = tweets.get(position);
        if (tweet != null) {

            ImageView image = (ImageView) v.findViewById(R.id.avatar);

            if (image != null) {
                image.setImageBitmap(getBitmap(tweet.image_url));
            }
        }
        return v;
    }
}

public Bitmap getBitmap(String bitmapUrl) {
    try {
        URL url = new URL(bitmapUrl);
        return BitmapFactory.decodeStream(url.openConnection()
                .getInputStream());
    } catch (Exception ex) {
        return null;
    }
}

public ArrayList<Tweet> getTweets() throws ClientProtocolException,
        IOException, JSONException {
    String searchUrl = "http://api.tumblr.com/v2/blog/www.richkidsofinstagram.tumblr.com/posts?api_key=API_KEY";

    ArrayList<Tweet> tweets = new ArrayList<Tweet>();

    HttpClient client = new DefaultHttpClient();
    HttpGet get = new HttpGet(searchUrl);

    ResponseHandler<String> responseHandler = new BasicResponseHandler();

    String responseBody = null;
    try {
        responseBody = client.execute(get, responseHandler);
    } catch (Exception ex) {
        ex.printStackTrace();
    }

    JSONObject jsonObject = new JSONObject(responseBody);

    JSONArray arr = null;

    try {
        arr = jsonObject.getJSONArray("results");
    } catch (Exception ex) {
        Log.v("TEST", "Exception: " + ex.getMessage());
    }

    for (int i = 0; i < arr.length(); i++) {
        Tweet tweet = new Tweet(arr.getJSONObject(i).getString("photos"));
        tweets.add(tweet);
    }

    return tweets;
}

public class Tweet {

    public String image_url;

    public Tweet(String url) {

        this.image_url = url;
    }
    }
    }

{
"meta": {
    "status": 200,
    "msg": "OK"
},
"response": {
    "blog": {
        "title": "Rich Kids Of Instagram",
        "posts": 154,
        "name": "richkidsofinstagram",
        "url": "http://richkidsofinstagram.tumblr.com/",
        "updated": 1346803265,
        "description": "They have more money than you and this is what they do.
        "ask": true,
        "ask_anon": true
    },
    "posts": [
        {
            "blog_name": "richkidsofinstagram",
            "id": 30900248446,
            "post_url":          "http://richkidsofinstagram.tumblr.com/post/30900248446/hamptons-are-good",
            "slug": "hamptons-are-good",
            "type": "photo",
            "date": "2012-09-04 23:58:45 GMT",
            "timestamp": 1346803125,
            "state": "published",
            "format": "html",
            "reblog_key": "2KosMjea",
            "tags": [
                "pool",
                "hamptons",
                "summer",
                "rich",
                "wealth"
            ],
            "highlighted": [],
            "note_count": 99,
            "caption": "<p><span>The Hamptons are…….. good. by matthewmorton</span></p>",
            "photos": [
                {
                    "caption": "",
                    "alt_sizes": [
                        {
                            "width": 500,
                            "height": 500,
                            "url": "http://24.media.tumblr.com/tumblr_m9uiqy9Mi71rb86ldo1_500.jpg"
                        },
                        {
                            "width": 400,
                            "height": 400,
                            "url": "http://25.media.tumblr.com/tumblr_m9uiqy9Mi71rb86ldo1_400.jpg"
                        },
                        {
                            "width": 250,
                            "height": 250,
                            "url": "http://25.media.tumblr.com/tumblr_m9uiqy9Mi71rb86ldo1_250.jpg"
                        },
                        {
                            "width": 100,
                            "height": 100,
                            "url": "http://25.media.tumblr.com/tumblr_m9uiqy9Mi71rb86ldo1_100.jpg"
                        },
                        {
                            "width": 75,
                            "height": 75,
                            "url": "http://25.media.tumblr.com/tumblr_m9uiqy9Mi71rb86ldo1_75sq.jpg"
                        }
                    ],
                    "original_size": {
                        "width": 500,
                        "height": 500,
                        "url": "http://24.media.tumblr.com/tumblr_m9uiqy9Mi71rb86ldo1_500.jpg"
                    }
                }
            ]
        },

{
“元”：{
“地位”：200，
“msg”：“好的”
},
“答复”：{
“博客”：{
“标题”：“Instagram的富家子弟”，
“员额”：154，
“名称”：“richkidsofinstagram”，
“url”：”http://richkidsofinstagram.tumblr.com/",
“更新”：1346803265，
“描述”：“他们的钱比你多，他们就是这么做的。
“问”：没错，
“问安”：对
},
“员额”：[
{
“博客名称”：“richkidsofinstagram”，
“id”：30900248446，
“发布url”：http://richkidsofinstagram.tumblr.com/post/30900248446/hamptons-are-good",
“鼻涕虫”：“汉普顿很好”，
“类型”：“照片”，
“日期”：“2012-09-04 23:58:45 GMT”，
“时间戳”：1346803125，
“国家”：“已出版”，
“格式”：“html”，
“重新登录密钥”：“2KosMjea”，
“标签”：[
“游泳池”，
“汉普顿”，
“夏天”，
“富有”，
“财富”
],
“突出显示”：[]，
“票据计数”：99，
“说明”：“汉普顿是……好的。作者：马修莫顿””，
“照片”：[
{
“标题”：“，
“alt_尺寸”：[
{
“宽度”：500，
“高度”：500，
“url”：”http://24.media.tumblr.com/tumblr_m9uiqy9Mi71rb86ldo1_500.jpg"
},
{
“宽度”：400，
“高度”：400，
“url”：”http://25.media.tumblr.com/tumblr_m9uiqy9Mi71rb86ldo1_400.jpg"
},
{
“宽度”：250，
“高度”：250，
“url”：”http://25.media.tumblr.com/tumblr_m9uiqy9Mi71rb86ldo1_250.jpg"
},
{
“宽度”：100，
“高度”：100，
“url”：”http://25.media.tumblr.com/tumblr_m9uiqy9Mi71rb86ldo1_100.jpg"
},
{
“宽度”：75，
“高度”：75，
“url”：
tweets.add(tweet);