Android開發之Google天氣顯示（綜合例子）

Android的google天氣顯示，包括讀取網絡信息，讀取xml，使用網絡信息二級制碼生成文件

1.生成url
2.獲取google返回的網絡信息 new InputSource(aURL.openStream())
3.生成解析xml的處理器
4.解析xml
5.封裝解析後的xml文件
6.根據解析後的數據，生成url，獲取google返回的天氣圖標，賦值給圖片

代碼：

                      /*獲取用戶輸入的城市名稱*/
                String city = ((EditText) findViewById(R.id.input))
                    .getText().toString();
               
                /*組成URL字符串*/
                //中文：http://www.google.com/ig/api?hl=zh-cn&weather=
                //英文：http://www.google.com/ig/api?weather=
                String queryString = "http://www.google.com/ig/api?weather="
                    + city;
                /*將可能的空格替換為"%20"*/
                URL aURL = new URL(queryString.replace(" ", "%20"));
                                       
                /* 從SAXParserFactory獲取SAXParser*/
                    SAXParserFactory spf = SAXParserFactory.newInstance();
                    SAXParser sp = spf.newSAXParser();

                    /* 從SAXParser得到XMLReader*/
                    XMLReader xr = sp.getXMLReader();

                    /*
                     * 創建GoogleWeatherHandler，以便解析XML內容
                     */
                    GoogleWeatherHandler gwh = new GoogleWeatherHandler();
                    xr.setContentHandler(gwh);

                    /* 解析XML文件內容 */
                    xr.parse(new InputSource(aURL.openStream()) );

                   
                    TextView tv1 = (TextView)findViewById(R.id.tem);
                    tv1.setText("溫度：" + gwh.getCurrentTemp() + "攝氏度");
                   
                    TextView tv2 = (TextView)findViewById(R.id.weather);
                    tv2.setText(gwh.getCurrentCondition());
                   
                    TextView tv3 = (TextView)findViewById(R.id.hum);
                    tv3.setText(""+ gwh.getCurrentHum() );
                   
                   
                    URL iconURL = new URL("http://www.google.com"+ gwh.getIconURL());
                URLConnection conn = iconURL.openConnection();
                    conn.connect();
                    InputStream is = conn.getInputStream();
                    BufferedInputStream bis = new BufferedInputStream(is);
                    //設置icon
                    ImageView iv = (ImageView)findViewById(R.id.iconOfWeather);
                    Bitmap bm = null;
                    bm = BitmapFactory.decodeStream(bis);
                    iv.setImageBitmap(bm);
                    bis.close();
                    is.close();

分析google返回的xml的處理類代碼：
     private boolean in_current_conditions = false;
     private boolean in_forecast_conditions = false;
    
     private Integer current_temp;
     private String current_condition;
     private String current_hum;
     private String iconURL;

     @Override
     public void startDocument() throws SAXException {
  
     }

     @Override
     public void endDocument() throws SAXException {
         
     }

     @Override
     public void startElement(String namespaceURI, String localName,
               String qName, Attributes atts) throws SAXException {
          // 'Outer' Tags
          if (localName.equals("forecast_information")) {
               this.in_forecast_information = true;
          } else if (localName.equals("current_conditions")) {
               this.in_current_conditions = true;
          } else if (localName.equals("forecast_conditions")) {
               this.in_forecast_conditions = true;
          } else {
               String dataAttribute = atts.getValue("data");
               // 'Inner' Tags of "<forecast_information>"
               if (localName.equals("city")) {
               } else if (localName.equals("postal_code")) {
               } else if (localName.equals("latitude_e6")) {
                    /* One could use this to convert city-name to Lat/Long. */
               } else if (localName.equals("longitude_e6")) {
                    /* One could use this to convert city-name to Lat/Long. */
               } else if (localName.equals("forecast_date")) {
               } else if (localName.equals("current_date_time")) {
               } else if (localName.equals("unit_system")) {
                    if (dataAttribute.equals("SI"))
                         this.usingSITemperature = true;
               }
               // SHARED(!) 'Inner' Tags within "<current_conditions>" AND
               // "<forecast_conditions>"
               else if (localName.equals("day_of_week")) {
                    if (this.in_current_conditions) {
                        //可擴展
                    } else if (this.in_forecast_conditions) {
                        //可擴展
                    }
               } else if (localName.equals("icon")) {
                    if (this.in_current_conditions) {
                        this.setIconURL(dataAttribute);
                    } else if (this.in_forecast_conditions) {
                    //可擴展
                    }
               } else if (localName.equals("condition")) {
                    if (this.in_current_conditions) {
                        this.setCurrentCondition(dataAttribute);
                    } else if (this.in_forecast_conditions) {
                    //可擴展
                    }
               }
               // 'Inner' Tags within "<current_conditions>"
               else if (localName.equals("temp_f")) {
                    //this.setCurrentTemp(Integer.parseInt(dataAttribute));
               } else if (localName.equals("temp_c")) {
                this.setCurrentTemp(Integer.parseInt(dataAttribute));
               } else if (localName.equals("humidity")) {
                    this.setCurrentHum(dataAttribute);
               } else if (localName.equals("wind_condition")) {
                    //可擴展    
               }
               // 'Inner' Tags within "<forecast_conditions>"
               else if (localName.equals("low")) {
                    int temp = Integer.parseInt(dataAttribute);
                    if (this.usingSITemperature) {
                    //可擴展 
                    } else {
                    //可擴展 
                    }
               } else if (localName.equals("high")) {
                    //int temp = Integer.parseInt(dataAttribute);
                    if (this.usingSITemperature) {
                    //可擴展 
                    } else {
                    //可擴展 
                    }
               }
          }
     }

     @Override
     public void endElement(String namespaceURI, String localName, String qName)
               throws SAXException {
          if (localName.equals("forecast_information")) {
               this.in_forecast_information = false;
          } else if (localName.equals("current_conditions")) {
               this.in_current_conditions = false;
          } else if (localName.equals("forecast_conditions")) {
               this.in_forecast_conditions = false;
          }
     }

     @Override
     public void characters(char ch[], int start, int length) {
          /*
           * 可擴展 <element>characters</element>
           */
     }