網路請求 + 使用子執行緒更新資料 + Asynctask實現非同步執行 + Gson解析
阿新 • • 發佈：2018-12-30
//主頁面MainActivity
public class MainActivity extends FragmentActivity {
private ViewPager pager; private RadioGroup radioGroup; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); findViewById( R.id.radioButton).setBackgroundColor(Color.RED); findViewById( R.id.radioButton2).setBackgroundColor(Color.GREEN); pager = findViewById(R.id.pager); radioGroup = findViewById(R.id.radiogroup); //預設選中第一個 radioGroup.check(radioGroup.getChildAt(0).getId()); //設定頁面滑動資料 ArrayList<Fragment> list=new ArrayList<Fragment>(); FragListview fragListview=new FragListview(); FragGridView fragGridView=new FragGridView(); list.add(fragListview); list.add(fragGridView); ///設定介面卡 pager.setAdapter(new MyFragmentAdapter(getSupportFragmentManager(),list)); //按鈕跟著頁面走 pager. addOnPageChangeListener(new ViewPager.OnPageChangeListener() { @Override public void onPageScrolled(int i, float v, int i1) { } @Override public void onPageSelected(int i) { //當頁面發生改變 按鈕也要跟著變 radioGroup.check(radioGroup.getChildAt(i).getId()); } @Override public void onPageScrollStateChanged(int i) { } }); //頁面跟著按鈕改變 radioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() { @Override public void onCheckedChanged(RadioGroup group, int checkedId) { //根據點選按鈕改變頁面 switch (checkedId){ case R.id.radioButton: findViewById( R.id.radioButton).setBackgroundColor(Color.RED); findViewById( R.id.radioButton2).setBackgroundColor(Color.GREEN); pager.setCurrentItem(0); break; case R.id.radioButton2: findViewById( R.id.radioButton).setBackgroundColor(Color.GREEN); findViewById( R.id.radioButton2).setBackgroundColor(Color.RED); pager.setCurrentItem(1); break; } } }); }
}
//2.FragListView 使用Gson解析
public class FragListview extends Fragment {
private ListView listView; @Nullable @Override public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) { View view = inflater.inflate(R.layout.fraglistview, container, false); listView = view.findViewById(R.id.listview); //解析網路資料 new Thread() { @Override public void run() { super.run(); //請求資料 String s = HttpUtile.requestHttpGet("https://api.apiopen.top/musicRankings"); //解析 Gson gson = new Gson(); JsonListBean listBean = gson.fromJson(s, JsonListBean.class); List<JsonListBean.ResultBean> list = listBean.getResult(); //子執行緒處理資料完畢 //更新ui Message message = new Message(); message.what = 0; message.obj = list; handler.sendMessage(message); } }.start(); return view; } Handler handler = new Handler() { @Override public void handleMessage(Message msg) { super.handleMessage(msg); switch (msg.what) { case 0: List<JsonListBean.ResultBean> list = (List<JsonListBean.ResultBean>) msg.obj; //展示到listview上 listView.setAdapter(new MyAdapter(list,getActivity())); break; } } };
}
//3.FragGridView網路格式
public class FragGridView extends Fragment implements MyAsyncTask.Callbacks {
private GridView grid; @Nullable @Override public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) { View view=inflater.inflate(R.layout.fraggradview,container,false); grid = view.findViewById(R.id.grid); //請求資料 MyAsyncTask task=new MyAsyncTask(); task.setCallbacks(this); task.execute("https://api.apiopen.top/musicRankings"); return view; } @Override public String getData(String string) { //解析 Gson gson = new Gson(); JsonListBean listBean = gson.fromJson(string, JsonListBean.class); List<JsonListBean.ResultBean> list = listBean.getResult(); grid.setAdapter(new MyAdapter(list,getActivity())); Toast.makeText(getActivity(),string,Toast.LENGTH_LONG).show(); return null; }
}
//4.HttpUtile
public class HttpUtile {
/**
* 請求資料GET請求
*/
public static String requestHttpGet(String strUrl) {
try { //設定url
URL url = new URL(strUrl);
//獲取HttpURLConnection
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
//設定為get請求
connection.setRequestMethod("GET");
//設定連線主機超時時間
connection.setConnectTimeout(5000);
//設定從主機讀取資料超時
connection.setReadTimeout(5000);
//獲取請求碼（來判斷網路請求是否正確）
int code = connection.getResponseCode();
//判斷請求是否成功
if (code == HttpURLConnection.HTTP_OK) {
//如果資料請求成功
//就獲取資料
InputStream stream = connection.getInputStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(stream, "utf-8"));
//拼接字串
StringBuilder builder = new StringBuilder();
//把資料讀取從成字串
String str = "";
while ((str = reader.readLine()) != null) {
//把一行行資料拼接成一行資料
builder.append(str);
}
//返回拼接後的資料
return builder.toString();
}
//關閉連線
connection.disconnect();
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
public static Bitmap httpGETImage(String string) {
try {
//設定URL
URL url = new URL(string);
//得到HttpURLConnection
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("GET");
//連線超時時間
connection.setConnectTimeout(5000);
//讀取超時
connection.setReadTimeout(5000);
//獲取請求碼 一般情況下200是成功
int code = connection.getResponseCode();
//判斷請求碼是否 請求成功
if (code == HttpURLConnection.HTTP_OK) {
//得到資料
InputStream stream = connection.getInputStream();
// 如果是圖片
Bitmap bitmap = BitmapFactory.decodeStream(stream);
return bitmap;
}
connection.disconnect();
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
//post請求
public static String httpPost(String str1, String str2) {
// http://apis.juhe.cn/cook/query ? key=&menu=蛋炒飯
try {
//設定url
URL url = new URL(str1);
//獲取HttpURLConnection
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
//設定為post請求
connection.setRequestMethod("POST");
//使用寫入和讀取(post請求必須要寫這個倆)
connection.setDoOutput(true);
connection.setDoInput(true);
//
PrintWriter writer = new PrintWriter(connection.getOutputStream());
writer.write(str2);// key= &menu=蛋炒飯
writer.flush();
;//重新整理
//判斷是否成功
int code = connection.getResponseCode();
if (code == 200) {
//讀取資料
InputStream stream = connection.getInputStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(stream, "utf-8"));
//拼接字串
StringBuilder builder = new StringBuilder();
String s = "";
//讀取資料
while ((s = reader.readLine()) != null) {
//拼接字串
builder.append(s);
}
return builder.toString();
}
connection.disconnect();
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
}
//5.MyAsyncTask
public class MyAsyncTask extends AsyncTask<String ,Void,String> {
@Override
protected String doInBackground(String… strings) {
return HttpUtile.requestHttpGet(strings[0]);
}
@Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
callbacks.getData(s);
}
public interface Callbacks{
String getData(String string);
}
private Callbacks callbacks;
public void setCallbacks(Callbacks callbacks) {
this.callbacks = callbacks;
}
}
//6.MyFragmentAdapter
public class MyFragmentAdapter extends FragmentPagerAdapter {
private ArrayList< Fragment> list;
public MyFragmentAdapter(FragmentManager fm, ArrayList<Fragment> list) {
super(fm);
this.list = list;
}
@Override
public Fragment getItem(int i) {
return list.get(i);
}
@Override
public int getCount() {
return list.size();
}
}
7.MyAdapter
public class MyAdapter extends BaseAdapter {
private List<JsonListBean.ResultBean> list;
private Context context;
public MyAdapter(List<JsonListBean.ResultBean> list, Context context) {
this.list = list;
this.context = context;
}
@Override
public int getCount() {
return list.size();
}
@Override
public Object getItem(int position) {
return null;
}
@Override
public long getItemId(int position) {
return 0;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder = null;
if (convertView == null) {
convertView = View.inflate(context, R.layout.item, null);
holder = new ViewHolder();
holder.text = convertView.findViewById(R.id.text);
holder.image = convertView.findViewById(R.id.image);
convertView.setTag(holder);
}
else {
holder= (ViewHolder) convertView.getTag();
}
JsonListBean.ResultBean resultBean = list.get(position);
holder.text.setText(resultBean.getName());
// holder.image.setImageBitmap( );
ImageLoader.getInstance().displayImage( resultBean.getPic_s444(), holder.image);
return convertView;
}
class ViewHolder {
TextView text;
ImageView image;
}
}
****8.App****
public class App extends Application {
@Override
public void onCreate() {
super.onCreate();
//配置屬性
DisplayImageOptions options = new DisplayImageOptions.Builder() .build();
//設定imageloader
ImageLoaderConfiguration loader = new ImageLoaderConfiguration.Builder(this)
.defaultDisplayImageOptions(options)//設定配置屬性
.build();
// 獲得例項
ImageLoader imageLoader = ImageLoader.getInstance();
// 初始化
imageLoader.init(loader);
}
}