android - 显示来自 json android 的图像

Question

嗨，我从 json 解析图像时遇到问题。我可以显示来自 json 的 textview，但未显示图像。

这里的代码

 package com.testimage;

import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;
import java.util.ArrayList;
import java.util.HashMap;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import android.app.Activity;
import android.app.ProgressDialog;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.widget.ImageView;
import android.widget.TextView;

public class DetailPeta extends Activity {

    ArrayList<HashMap<String, String>> dataMap = new ArrayList<HashMap<String, String>>();
    private ProgressDialog pDialog;
    JSONParser jParser = new JSONParser();

    JSONArray str_json = null;
    Koneksi lo_Koneksi = new Koneksi();
    String isi = lo_Koneksi.isi_koneksi();
    String link_url = isi + "detail.php";
    TextView judul_set, keterangan_set, tanggal_set;
    ImageView gambar_set;

    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.detail_peta);

        keterangan_set = (TextView) findViewById(R.id.keterangan);
        judul_set = (TextView) findViewById(R.id.judul);
        tanggal_set = (TextView) findViewById(R.id.tanggal);
        gambar_set = (ImageView) findViewById(R.id.gambar);

        Bundle b = getIntent().getExtras();
        String nama = b.getString("nama");

        link_url = isi + "detail.php?nama="+nama;
        new getListInfo().execute();
    }

    class getListInfo extends AsyncTask<String, String, String> {
        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            pDialog = new ProgressDialog(DetailPeta.this);
            pDialog.setMessage("Menghubungkan ke server...");
            pDialog.setIndeterminate(false);
            pDialog.setCancelable(true);
            pDialog.show();
        }

        protected String doInBackground(String... args) {

            JSONObject json = jParser.AmbilJson(link_url);

            try {
                str_json = json.getJSONArray("info");

                for(int i = 0; i < str_json.length(); i++)
                {
                    JSONObject ar = str_json.getJSONObject(i);
                    HashMap<String, String> map = new HashMap<String, String>();

                    map.put("nama", ar.getString("nama"));
                    map.put("lat",  ar.getString("lat"));
                    map.put("lng",  ar.getString("lng"));
                    map.put("Tanggal",  ar.getString("Tanggal"));
                    map.put("deskrpsi",  ar.getString("deskripsi"));
                    map.put("gambar",  ar.getString("gambar"));

                    dataMap.add(map);
                }
            } catch (JSONException e) {
                e.printStackTrace();
            }

            return null;
        }

        protected void onPostExecute(String file_url) {
            pDialog.dismiss();
            runOnUiThread(new Runnable() {
                public void run() {

                    for (int i = 0; i < dataMap.size(); i++)
                    {
                        HashMap<String, String> map = new HashMap<String, String>();
                        map = dataMap.get(i);
                        judul_set.setText(map.get("nama"));
                        keterangan_set.setText(map.get("deskrpsi"));
                        tanggal_set.setText(map.get("Tanggal"));

                        new DownloadImagesTask().execute(isi+"detil.php"+map.get("gambar"));
                    }
                }
            });
        }

    }
    public class DownloadImagesTask extends AsyncTask<String, Void, Bitmap> {

        @Override
        protected Bitmap doInBackground(String... urls) {
            return download_Image(urls[0]);
        }

        @Override
        protected void onPostExecute(Bitmap result) {
            gambar_set.setImageBitmap(result);
        }

        private Bitmap download_Image(String url) {
            Bitmap bm = null;
            try {
                URL aURL = new URL(url);
                URLConnection conn = aURL.openConnection();
                conn.connect();
                InputStream is = conn.getInputStream();
                BufferedInputStream bis = new BufferedInputStream(is);
                bm = BitmapFactory.decodeStream(bis);
                bis.close();
                is.close();
            } catch (IOException e) {
                Log.e("Hub","Error getting the image from server : " + e.getMessage().toString());
            }
            return bm;
        }
    }
}

我可以解析来自 nama 和 keterangan 的文本，但未显示图像。

display_detail.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:padding="10dp" >

<ScrollView
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
>
    <LinearLayout
    android:layout_height="wrap_content" android:layout_width="fill_parent"
    android:orientation="vertical" >

    <TextView android:text=""
        android:layout_height="wrap_content"
        android:id="@+id/judul"
        android:textSize="20sp"
        android:textColor="#000"
        android:layout_width="fill_parent" >
    </TextView>

    <ImageView
        android:layout_height="200dp"
        android:id="@+id/gambar"
        android:layout_width="fill_parent" >
    </ImageView>

    <TextView android:text=""
        android:layout_height="wrap_content"
        android:id="@+id/keterangan"
        android:textSize="14sp"
        android:textColor="#000"
        android:layout_width="fill_parent" >
    </TextView>

</LinearLayout>
</ScrollView>

</LinearLayout>

请帮我解决这个问题