PM2.5 AQI

#python
import json,urllib
from urllib import urlencode

url = 'http://api.k780.com'
params = {
  'app' : 'weather.pm25',
  'weaId' : '城市编号',
  'appkey' : 'APPKEY',
  'sign' : 'SIGN',
  'format' : 'json',
}
params = urlencode(params)

f = urllib.urlopen('%s?%s' % (url, params))
nowapi_call = f.read()
#print content
a_result = json.loads(nowapi_call)
if a_result:
  if a_result['success'] != '0':
    print a_result['result'];
  else:
    print a_result['msgid']+' '+a_result['msg']
else:
  print 'Request nowapi fail.';

import java.net.*;
import java.io.*;

public class test{
    public static void main(String args[]) throws Exception {
        URL u=new URL("http://api.k780.com/?app=weather.pm25&weaId=城市编号&appkey=APPKEY&sign=SIGN&format=json");
        InputStream in=u.openStream();
        ByteArrayOutputStream out=new ByteArrayOutputStream();
        try {
            byte buf[]=new byte[1024];
            int read = 0;
            while ((read = in.read(buf)) > 0) {
                out.write(buf, 0, read);
            }
        }  finally {
            if (in != null) {
                in.close();
            }
        }
        byte b[]=out.toByteArray( );
        System.out.println(new String(b,"utf-8"));
    }
}

curl "http://api.k780.com/?app=weather.pm25&weaId=城市编号&appkey=10003&sign=b59bc3ef6191eb9f747dd4e83c99f2a4&format=json"