我需要在列表视图中解析和显示 url 内容。我已经使用延迟加载解析了标题、日期、内容、名称和图像，但现在我需要解析 url 并在列表视图中显示其内容。但这里的问题不是显示 url，而是显示图像 url。它像这样显示http://imageshack.us/photo/my-images/18/device20130202121840.png/以下是我的 json 响应（这里只包含几个响应）和解析代码
"posts": [
{
"id": 2954,
"type": "ad_listing",
"slug": "commander-retreat-for-sale",
"url": "http://avoidserum/ads/commander-retreat-for-sale/",
"status": "publish",
"title": "Commander Retreat for sale",
"title_plain": "Commander Retreat for sale",
"content": "<p>Commander Retreat : Hebbal Lake<br />\n2 BHK<br />\nBuilt up: 1180sft<br />\n3rd floor<br />\nTotal G+3 floors<br />\nWest facing<br />\nFurnished<br />\nSale price Rs. 50lacs ( nego)<br />\nFor further details please call M/s. Farid Consultants @ 9844106901 /9880123548<br />\nEmail: manjula@faridconsultants.com</p>\n",
"excerpt": "Commander Retreat : Hebbal Lake 2 BHK Built up: 1180sft 3rd floor Total G+3 floors West facing Furnished Sale price Rs. 50lacs ( nego) For further details please call M/s. Farid Consultants @ 9844106901 /9880123548 Email: manjula@faridconsultants.com",
"date": "2013-02-01 05:09:58",
"modified": "2013-02-01 05:09:58",
"categories": [],
"tags": [],
"author": {
"id": 344,
"slug": "ruby",
"name": "Ruby",
"first_name": "",
"last_name": "",
"nickname": "Ruby",
"url": "",
"description": ""
},
"comments": [],
"attachments": [
{
"id": 2955,
"url": "http://imageurl/wp-content/uploads/2013/01/785862.jpg",
"slug": "commander-retreat-for-sale",
"title": "Commander Retreat for sale",
"description": "",
"caption": "",
"parent": 2954,
"mime_type": "image/jpeg",
},
.....................
解析代码
static final String KEY_POSTS = "posts";
static final String KEY_ID = "id";
static final String KEY_SITEURL = "url";
static final String KEY_TITLE = "title";
static final String KEY_DATE = "date";
static final String KEY_CONTENT = "content";
static final String KEY_AUTHOR = "author";
static final String KEY_NAME = "name";
static final String KEY_ATTACHMENTS = "attachments";
static final String KEY_SLUG = "slug";
static final String KEY_THUMB_URL = "thumbnail";
static final String KEY_IMAGES = "images";
static final String KEY_URL = "url";
final ArrayList<HashMap<String, String>> songsList = new ArrayList<HashMap<String, String>>();
// Creating JSON Parser instance
final JSONParser jParser = new JSONParser();
// getting JSON string from URL
JSONObject json = jParser.getJSONFromUrl(URL);
try {
posts = json.getJSONArray(KEY_POSTS);
// looping through all song nodes <song>
for(int i = 0; i < posts.length(); i++){
JSONObject c = posts.getJSONObject(i);
// Storing each json item in variable
String id = c.getString(KEY_ID);
String siteurl = c.getString(KEY_SITEURL);
String title = c.getString(KEY_TITLE);
String date = c.getString(KEY_DATE);
String content = c.getString(KEY_CONTENT);
// to remove all <P> </p> and <br /> and replace with ""
content = content.replace("<br />", "");
content = content.replace("<p>", "");
content = content.replace("</p>", "");
//authornumber is agin JSON Object
JSONObject author = c.getJSONObject(KEY_AUTHOR);
String name = author.getString(KEY_NAME);
String url1 = null;
String slug1 = null;
try {
JSONArray atta = c.getJSONArray("attachments");
for(int j = 0; j < atta.length(); j++){
JSONObject d = atta.getJSONObject(j);
slug1 = d.getString(KEY_SLUG);
JSONObject images = d.getJSONObject(KEY_IMAGES);
JSONObject thumbnail = images.getJSONObject(KEY_THUMB_URL);
url1 = thumbnail.getString(KEY_URL);
}
} catch (Exception e) {
e.printStackTrace();
}
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(KEY_ID, id);
map.put(KEY_TITLE, title);
map.put(KEY_SITEURL, siteurl);
map.put(KEY_DATE, date);
map.put(KEY_NAME, name);
map.put(KEY_CONTENT, content);
map.put(KEY_SLUG, slug1);
map.put(KEY_URL, url1);
// adding HashList to ArrayList
songsList.add(map);
}
}catch (JSONException e) {
e.printStackTrace();
}
final ListView list=(ListView)findViewById(android.R.id.list);
// Getting adapter by passing json data ArrayList
adapter=new LazyAdapter(this, songsList);
list.setAdapter(adapter);
LazyAdapter.java
public class LazyAdapter extends BaseAdapter {
private Activity activity;
private ArrayList<HashMap<String, String>> data;
private static LayoutInflater inflater=null;
public ImageLoader imageLoader;
public LazyAdapter(Activity a, ArrayList<HashMap<String, String>> d) {
activity = a;
data=d;
inflater = (LayoutInflater)activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
imageLoader=new ImageLoader(activity.getApplicationContext());
}
public int getCount() {
return data.size();
}
public Object getItem(int position) {
return position;
}
public long getItemId(int position) {
return position;
}
public View getView(int position, View convertView, ViewGroup parent) {
View vi=convertView;
if(convertView==null)
vi = inflater.inflate(R.layout.list_item, null);
TextView title = (TextView)vi.findViewById(R.id.title); // title
TextView siteurl = (TextView)vi.findViewById(R.id.siteurl);
TextView date = (TextView)vi.findViewById(R.id.date); // artist name
TextView content = (TextView)vi.findViewById(R.id.content); // duration
TextView name = (TextView)vi.findViewById(R.id.name);
// duration
ImageView thumb_image=(ImageView)vi.findViewById(R.id.list_image); // thumb image
HashMap<String, String> song = new HashMap<String, String>();
song = data.get(position);
ListView list;
// Setting all values in listview
title.setText(song.get(MainActivity.KEY_TITLE));
siteurl.setText(song.get(MainActivity.KEY_SITEURL));
date.setText(song.get(MainActivity.KEY_DATE));
content.setText(song.get(MainActivity.KEY_CONTENT));
name.setText(song.get(MainActivity.KEY_NAME));
imageLoader.DisplayImage(song.get(MainActivity.KEY_URL), thumb_image);
return vi;
}
}
ImageLoader.java
public class ImageLoader {
MemoryCache memoryCache=new MemoryCache();
FileCache fileCache;
private Map<ImageView, String> imageViews=Collections.synchronizedMap(new WeakHashMap<ImageView, String>());
ExecutorService executorService;
public ImageLoader(Context context){
fileCache=new FileCache(context);
executorService=Executors.newFixedThreadPool(5);
}
final int stub_id = R.drawable.dollardesi;
public void DisplayImage(String url, ImageView imageView)
{
imageViews.put(imageView, url);
Bitmap bitmap=memoryCache.get(url);
System.out.println("Image bitmap object from url*********$$$$$$$$"+bitmap);
if(bitmap!=null)
imageView.setImageBitmap(bitmap);
else
{
System.out.println("In the else where there is null bitmap>>>>>>>>>");
queuePhoto(url, imageView);
imageView.setImageResource(stub_id);
}
}
private void queuePhoto(String url, ImageView imageView)
{
PhotoToLoad p=new PhotoToLoad(url, imageView);
executorService.submit(new PhotosLoader(p));
}
private Bitmap getBitmap(String url)
{
File f=fileCache.getFile(url);
//from SD cache
Bitmap b = decodeFile(f);
if(b!=null)
return b;
//from web
try {
Bitmap bitmap=null;
URL imageUrl = new URL(url);
HttpURLConnection conn = (HttpURLConnection)imageUrl.openConnection();
conn.setConnectTimeout(30000);
conn.setReadTimeout(30000);
conn.setInstanceFollowRedirects(true);
InputStream is=conn.getInputStream();
OutputStream os = new FileOutputStream(f);
Utils.CopyStream(is, os);
os.close();
bitmap = decodeFile(f);
return bitmap;
} catch (Exception ex){
ex.printStackTrace();
return null;
}
}
//decodes image and scales it to reduce memory consumption
private Bitmap decodeFile(File f){
try {
//decode image size
BitmapFactory.Options o = new BitmapFactory.Options();
o.inJustDecodeBounds = true;
BitmapFactory.decodeStream(new FileInputStream(f),null,o);
//Find the correct scale value. It should be the power of 2.
final int REQUIRED_SIZE=70;
int width_tmp=o.outWidth, height_tmp=o.outHeight;
int scale=1;
while(true){
if(width_tmp/2<REQUIRED_SIZE || height_tmp/2<REQUIRED_SIZE)
break;
width_tmp/=2;
height_tmp/=2;
scale*=2;
}
//decode with inSampleSize
BitmapFactory.Options o2 = new BitmapFactory.Options();
o2.inSampleSize=scale;
return BitmapFactory.decodeStream(new FileInputStream(f), null, o2);
} catch (FileNotFoundException e) {}
return null;
}
//Task for the queue
private class PhotoToLoad
{
public String url;
public ImageView imageView;
public PhotoToLoad(String u, ImageView i){
url=u;
imageView=i;
}
}
class PhotosLoader implements Runnable {
PhotoToLoad photoToLoad;
PhotosLoader(PhotoToLoad photoToLoad){
this.photoToLoad=photoToLoad;
}
@Override
public void run() {
if(imageViewReused(photoToLoad))
return;
Bitmap bmp=getBitmap(photoToLoad.url);
memoryCache.put(photoToLoad.url, bmp);
if(imageViewReused(photoToLoad))
return;
BitmapDisplayer bd=new BitmapDisplayer(bmp, photoToLoad);
Activity a=(Activity)photoToLoad.imageView.getContext();
a.runOnUiThread(bd);
}
}
boolean imageViewReused(PhotoToLoad photoToLoad){
String tag=imageViews.get(photoToLoad.imageView);
if(tag==null || !tag.equals(photoToLoad.url))
return true;
return false;
}
//Used to display bitmap in the UI thread
class BitmapDisplayer implements Runnable
{
Bitmap bitmap;
PhotoToLoad photoToLoad;
public BitmapDisplayer(Bitmap b, PhotoToLoad p){bitmap=b;photoToLoad=p;}
public void run()
{
if(imageViewReused(photoToLoad))
return;
if(bitmap!=null)
photoToLoad.imageView.setImageBitmap(bitmap);
else
photoToLoad.imageView.setImageResource(stub_id);
}
}
public void clearCache() {
memoryCache.clear();
fileCache.clear();
}
}