我正在尝试获取数据并将其设置为listview ....我已经看过教程并构建了自己的逻辑但是没有错误在logcat ....但应用程序显示空白页
我试图重复删除程序，以便在调试第二个tryCatch块后自动跳过它.......
package com.example.altaf;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.HashMap;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.annotation.SuppressLint;
import android.os.Bundle;
import android.os.StrictMode;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.os.Build;
public class MainActivity extends ActionBarActivity {
String id,name,email,address,gender,phone,mobile,home,office,contacts,line;
String CONTACT="contact";
InputStream is;
String response;
ListView lv;
SimpleAdapter sadp;
ArrayList<HashMap<String, String>>list=new ArrayList<HashMap<String,String>>();
String url="http://api.androidhive.info/contacts/";
@SuppressLint("NewApi")
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder()
.permitAll().build();StrictMode.setThreadPolicy(policy);
lv=(ListView)findViewById(R.id.listView1);
ArrayList<NameValuePair> namevalue = new ArrayList<NameValuePair>();
list=new ArrayList<HashMap<String,String>>();
try {
HttpClient hpclient = new DefaultHttpClient();
HttpGet httpGet=new HttpGet(url);
HttpPost httppost = new HttpPost(url);
httppost.setEntity(new UrlEncodedFormEntity(namevalue));
HttpResponse response = hpclient.execute(httppost);
HttpEntity entity = response.getEntity();
is = entity.getContent();
Log.e("pass1", "Connection sucess");
} catch (Exception e) {
Log.e("fail", e.toString());
}
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(is, "iso-8859-1"), 8);
StringBuilder sb = new StringBuilder();
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
response = sb.toString();
Log.e("pass2", "sucess");
} catch (Exception e) {
Log.e("fail", e.toString());
}
try {
JSONObject objsnrry = new JSONObject(response);
JSONArray arr = objsnrry.getJSONArray(CONTACT);
String nm = " ";
for (int i = 0; i < arr.length(); i++)
{
JSONObject obj = arr.getJSONObject(i);
String id = obj.getString("id");
String name = obj.getString("name");
String email = obj.getString("email");
String address = obj.getString("address");
String gender = obj.getString("gender");
JSONObject phone1 = obj.getJSONObject("phone");
String mobile1 = phone1.getString("mobile");
String home1 = phone1.getString("home");
String office1 = phone1.getString("office");
HashMap<String, String> map = new HashMap<String, String>();
map.put("id", id);
map.put("name", name);
map.put("email", email);
map.put("address", address);
map.put("mobile",mobile1);
list.add(map);
}
} catch (JSONException e) {
e.printStackTrace();
}
sadp = new SimpleAdapter(this, list,
R.layout.altaf, new String[] { "name",
"email", "mobile" }, new int[] { R.id.name,
R.id.emai, R.id.mobile });
lv.setAdapter(sadp);
}
}
答案 0 :(得分：1)
您正在获取UI线程上的网络操作的例外，因为您正在捕获异常，这就是您无法看到它的原因。 使用AsyncTask ...
private class CopyAsync extends AsyncTask<Void, Void, Void>{
ProgressDialog pd = null;
@Override
protected void onPreExecute()
{
// TODO Auto-generated method stub
super.onPreExecute();
pd = ProgressDialog.show(MainActivity.this, "Loading data ...", "Please wait...");
}
@Override
protected void doInBackground(Void... arg0)
{
try {
HttpClient hpclient = new DefaultHttpClient();
HttpGet httpGet=new HttpGet(url);
HttpPost httppost = new HttpPost(url);
httppost.setEntity(new UrlEncodedFormEntity(namevalue));
HttpResponse response = hpclient.execute(httppost);
HttpEntity entity = response.getEntity();
is = entity.getContent();
Log.e("pass1", "Connection sucess");
} catch (Exception e) {
Log.e("fail", e.toString());
}
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(is, "iso-8859-1"), 8);
StringBuilder sb = new StringBuilder();
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
response = sb.toString();
Log.e("pass2", "sucess");
} catch (Exception e) {
Log.e("fail", e.toString());
}
try {
JSONObject objsnrry = new JSONObject(response);
JSONArray arr = objsnrry.getJSONArray(CONTACT);
String nm = " ";
for (int i = 0; i < arr.length(); i++)
{
JSONObject obj = arr.getJSONObject(i);
String id = obj.getString("id");
String name = obj.getString("name");
String email = obj.getString("email");
String address = obj.getString("address");
String gender = obj.getString("gender");
JSONObject phone1 = obj.getJSONObject("phone");
String mobile1 = phone1.getString("mobile");
String home1 = phone1.getString("home");
String office1 = phone1.getString("office");
HashMap<String, String> map = new HashMap<String, String>();
map.put("id", id);
map.put("name", name);
map.put("email", email);
map.put("address", address);
map.put("mobile",mobile1);
list.add(map);
}
} catch (JSONException e) {
e.printStackTrace();
}
@Override
protected void onPostExecute(LinkedList<String> spinList)
{
// TODO Auto-generated method stub
super.onPostExecute(spinList);
if(pd!=null) pd.dismiss();
sadp = new SimpleAdapter(this, list,
R.layout.altaf, new String[] { "name",
"email", "mobile" }, new int[] { R.id.name,
R.id.emai, R.id.mobile });
lv.setAdapter(sadp);
}
}
并从OnCreate中调用它;
new CopyAsync ().execute();
并且不要忘记将Internet权限放入清单中。
我建议的另一件事，总是以适当的方式关闭（流，读者，游标等）。 喜欢：
BufferedReader reader=null;
try {
reader = new BufferedReader(new InputStreamReader(is, "iso-8859-1"), 8);
StringBuilder sb = new StringBuilder();
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
response = sb.toString();
Log.e("pass2", "sucess");
} catch (Exception e) {
Log.e("fail", e.toString());
}finally{
try{
is.close()
reader.close()
}catch(Exception e){ //like my Ex gf.. i don't care }
}