json数据中有图片的url，怎么把url添加到imageview中，谢谢大家

这是我获取数据的代码，还有顺便问一下怎么写线程
try {

                        JSONObject  dataJson=new JSONObject(responseString);
                        JSONArray data=dataJson.getJSONArray("retData");
                      // 创建一个List集合，List集合的元素是Map
                        List<Map<String, Object>> listItems =new ArrayList<Map<String, Object>>();
                        for (int i = 0; i < 5; i++) {
                            JSONObject info = data.getJSONObject(i);
                            Map<String, Object> listItem = new HashMap<String, Object>();
                            Bitmap bit= BitmapFactory.decodeFile(info.getString("img_url"));
                            listItem.put("title", info.getString("title"));
                            listItem.put("image", bit);
                            listItem.put("abs", info.getString("abstract"));
                            listItems.add(listItem);
                        }
                        // 创建一个SimpleAdapter
                        SimpleAdapter simpleAdapter = new SimpleAdapter(getActivity(), listItems,R.layout.news_simple_item,
                                new String[]{"image", "title", "abs"},
                                new int[]{R.id.image, R.id.title, R.id.abs});
                        ListView list = (ListView) view.findViewById(R.id.chat_news);
                        // 为ListView设置Adapter
                        list.setAdapter(simpleAdapter);

发错了不好意思你没这个glide的jar文件，用这个吧：
dependencies {
compile 'com.github.bumptech.glide:glide:3.6.1'
}

你这个应该是android的吧，你可以使用第三方的图片加载库glide来实现加载，非常简单，先在build.gradle的dependencies中添加

dependencies {
compile files('libs/glide-3.6.1.jar')
}
然后需要重新编译一下程序，实现下面代码就可以加载了：
Glide.with(this).load(url).asBitmap().into(imagView);

simpleAdapter.setViewBinder(new ViewBinder() {

        @Override
        public boolean setViewValue(View view, Object data,
                String textRepresentation) {
            if (view instanceof ImageView && data instanceof Bitmap) {
                ImageView iv = (ImageView) view;
                iv.setImageBitmap((Bitmap) data);
                return true;
            }
            return false;
        }
    });

list.setAdapter(simpleAdapter);
这是网上的答案，是我的话应该会重写adapter

public class Adapter extends BaseAdapter{

private Context context;
private int itemLayoutID;
private int[] itemIds;
private List<Map<String, Object>> listItems;

public Adapter(Context context, int itemLayoutID,
        int[] itemIds, List<Map<String, Object>> listItems ) {
    this.context = context;
    this.itemLayoutID = itemLayoutID;
    this.itemIds = itemIds;
    this.listItems = listItems;
}

@Override
public int getCount() {
    // TODO Auto-generated method stub
    return listItems.size();
}

@Override
public Object getItem(int arg0) {
    // TODO Auto-generated method stub
    return listItems.get(arg0);
}

@Override
public long getItemId(int arg0) {
    // TODO Auto-generated method stub
    return 0;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    // TODO Auto-generated method stub
    ViewHolder holder;
    if (convertView == null) {
        LayoutInflater layoutInflater = LayoutInflater.from(context);
        convertView = layoutInflater.inflate(itemLayoutID, null);
        holder = new ViewHolder();
        holder.title = (TextView) convertView
                .findViewById(itemIds[0]);
        holder.image = (ImageView) convertView
                .findViewById(itemIds[1]);
        holder.abs = (TextView) convertView
                .findViewById(itemIds[2]);
        convertView.setTag(holder);

    } else {
        holder = (ViewHolder) convertView.getTag();
    }

    holder.title.setText((String)listItems.get(position).get("title"));
    Bitmap bit = BitmapFactory.decodeFile((String)listItems.get(position).get("img_url"));
    holder.image.setImageBitmap(bit);
    holder.abs.setText((String)listItems.get(position).get("abs"));
    return null;
}


static class ViewHolder {
    public TextView title;
    public ImageView image;
    public TextView abs;
}

}

    JSONObject  dataJson=new JSONObject(responseString);
    JSONArray data=dataJson.getJSONArray("retData");
  // 创建一个List集合，List集合的元素是Map
    List<Map<String, Object>> listItems =new ArrayList<Map<String, Object>>();
    for (int i = 0; i < 5; i++) {
        JSONObject info = data.getJSONObject(i);
        Map<String, Object> listItem = new HashMap<String, Object>();     
        listItem.put("title", info.getString("title"));
        listItem.put("image", info.getString("img_url"));
        listItem.put("abs", info.getString("abstract"));
        listItems.add(listItem);
    }
    Adapter adapter = new Adapter(getActivity(),R.layout.news_simple_item,
            new int[]{R.id.image, R.id.title, R.id.abs}, listItems);
    ListView list = (ListView) view.findViewById(R.id.chat_news);
    // 为ListView设置Adapter
    list.setAdapter(adapter);