在线升级Android程序

http://www.javaeye.com/topic/792774 

如果某个app有内嵌的sqlite数据库，则可以在应用程序app前增加一个专门用于升级的应用update app。在升级时先使用update app，如果有新版本的话可以去服务端下载最新的app，如果没有新版本的话则直接调用本地的app。

Update app的大致思路是这样的：
  

public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        mDB = new MapVersionTable(this);

        if (checkNewVersion()) {

            if (apkUrl == null)
                return;

            downloadAPK(apkUrl);
            killProcess();
            installAPK();
            finish();
        } else {
            if (checkApp()) {
                invokeAPK();
                finish();
            }else {
                downloadAPK(apkUrl);
                installAPK();
                finish();
            }
        }
    }

public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        mDB = new MapVersionTable(this);
        
        if (checkNewVersion()) {
        	
        	if (apkUrl == null) 
        		return;
        	
        	downloadAPK(apkUrl);
        	killProcess();
        	installAPK();
        	finish();
        } else {
        	if (checkApp()) {
        		invokeAPK();
                finish();
        	}else {
        		downloadAPK(apkUrl);
        		installAPK();
            	finish();
        	}
        }
    }

其中MapVersionTable是用于update app记录应用程序版本的。

checkNewVersion()用于检查是否有新版本的存在，并将服务端的版本号存入mapVersion变量，将服务端的应用地址存放在apkUrl变量。这段检查应用程序的方法，其实是利用rest方式进行访问，当然也可以用web service或者其他通讯方式。
 

private boolean checkNewVersion() {
        try {
            URL url=new URL(AppConfig.REST_URL);

            SAXParserFactory factory=SAXParserFactory.newInstance();
            factory.setNamespaceAware(true);
            factory.setValidating(false);
            SAXParser parser=factory.newSAXParser();
            InputStream is = url.openStream();
            parser.parse(is, new DefaultHandler(){
                private String cur="";
                private int step;

                @Override
                public void startDocument() throws SAXException {
                    step = 0;
                }

                @Override
                public void startElement(String uri, String localName,
                        String qName, Attributes attributes)
                        throws SAXException {
                    cur = localName;
                }

                @Override
                public void characters(char[] ch, int start, int length)
                        throws SAXException {
                    String str = new String(ch, start, length).trim();
                    if (str == null || str.equals(""))
                        return;
                    if (cur.equals("url")) {
                        apkUrl = str;
                    }
                    if (cur.equals("map_version")) {
                        mapVersion = str;
                    }
                }

                @Override
                public void endElement(String uri, String localName,
                        String qName) throws SAXException {
                    step = step + 1;
                }

                @Override
                public void endDocument() throws SAXException {
                    super.endDocument();
                }
            });
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (ParserConfigurationException e) {
            e.printStackTrace();
        } catch (SAXException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        if (diffVersion(mapVersion))
            return true;
        else
            return false;
    }

private boolean checkNewVersion() {
		try {
			URL url=new URL(AppConfig.REST_URL);
			
			SAXParserFactory factory=SAXParserFactory.newInstance();
			factory.setNamespaceAware(true);
			factory.setValidating(false);
		    SAXParser parser=factory.newSAXParser();
		    InputStream is = url.openStream();
		    parser.parse(is, new DefaultHandler(){
				private String cur="";
				private int step;
				
				@Override
				public void startDocument() throws SAXException {
					step = 0;
				}
				
				@Override
				public void startElement(String uri, String localName,
						String qName, Attributes attributes)
						throws SAXException {
					cur = localName;
				}
				
				@Override
				public void characters(char[] ch, int start, int length)
						throws SAXException {
					String str = new String(ch, start, length).trim();
					if (str == null || str.equals(""))
						return;
					if (cur.equals("url")) {
						apkUrl = str;
					}
					if (cur.equals("map_version")) {
						mapVersion = str;
					}
				}
				
				@Override
				public void endElement(String uri, String localName,
						String qName) throws SAXException {
					step = step + 1;
				}
				
				@Override
				public void endDocument() throws SAXException {
					super.endDocument();
				}
			});
		} catch (MalformedURLException e) {
			e.printStackTrace();
		} catch (ParserConfigurationException e) {
			e.printStackTrace();
		} catch (SAXException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
		if (diffVersion(mapVersion)) 
			return true;
		else
			return false;
	}

diffVersion()是将服务端版本号和本地版本号进行比较，如果存在新版本，则将最新的版本号存入数据库并调用downloadAPK()；如果不存在新版本，则会调用本地的app。不过在调用本地app前需要先判断本地的app是否安装，这个时候使用checkApp()方法。
 

private boolean diffVersion(String mapVersion) {
        String lastVersion = mDB.getLastMapVersion();
        if (lastVersion == null) {
            mDB.setMapVersion(mapVersion);
            return true;
        }

        if (!lastVersion.equals(mapVersion)) {
            mDB.setMapVersion(mapVersion);
            return true;
        }
        else
            return false;
    }

private boolean diffVersion(String mapVersion) {
		String lastVersion = mDB.getLastMapVersion();
		if (lastVersion == null) {
			mDB.setMapVersion(mapVersion);
			return true;
		}
		
		if (!lastVersion.equals(mapVersion)) {
			mDB.setMapVersion(mapVersion);
			return true;
		}
		else
			return false;
	}

    checkApp()该方法用于检查本地是否安装该app
 

private boolean checkApp() {
        Intent intent = new Intent(Intent.ACTION_VIEW);
        intent.setClassName("com.android.settings",
                "com.android.settings.InstalledAppDetails");
        intent.putExtra("com.android.settings.ApplicationPkgName",
                AppConfig.APKNAME);
        List<ResolveInfo> acts = getPackageManager().queryIntentActivities(
                intent, 0);
        if (acts.size() > 0) {
            return true;
        } else
            return false;
    }

private boolean checkApp() {
		Intent intent = new Intent(Intent.ACTION_VIEW);  
		intent.setClassName("com.android.settings", 
		        "com.android.settings.InstalledAppDetails"); 
		intent.putExtra("com.android.settings.ApplicationPkgName",  
				AppConfig.APKNAME);  
		List<ResolveInfo> acts = getPackageManager().queryIntentActivities(  
		        intent, 0);  
		if (acts.size() > 0) {  
			return true;
		} else
			return false;
	}

killProcess()是杀掉进程，防止升级时该应用还在使用。
 

private void killProcess() {
        activityMan = (ActivityManager)getSystemService(Context.ACTIVITY_SERVICE);
        process = activityMan.getRunningAppProcesses();

        int len = process.size();
        for(int i = 0;i<len;i++) {
            if (process.get(i).processName.equals(AppConfig.PKG)) {
                android.os.Process.killProcess(process.get(i).pid);
            }
        }
    }

private void killProcess() {
		activityMan = (ActivityManager)getSystemService(Context.ACTIVITY_SERVICE);
		process = activityMan.getRunningAppProcesses();
		
		int len = process.size();
		for(int i = 0;i<len;i++) {
			if (process.get(i).processName.equals(AppConfig.PKG)) {
				android.os.Process.killProcess(process.get(i).pid);
			}
		}
	}

    installAPK()将下载的app进行安装
 

private void installAPK() {
        String fileName = getSDPath() +"/download/"+AppConfig.APKNAME;
        Intent intent = new Intent(Intent.ACTION_VIEW);
        intent.setDataAndType(Uri.fromFile(new File(fileName)), "application/vnd.android.package-archive");
        startActivity(intent);
    }

private void installAPK() {
		String fileName = getSDPath() +"/download/"+AppConfig.APKNAME;
		Intent intent = new Intent(Intent.ACTION_VIEW);
		intent.setDataAndType(Uri.fromFile(new File(fileName)), "application/vnd.android.package-archive");
		startActivity(intent);
	}

invokeAPK()根据包名，调用本地的应用。
 

private void invokeAPK() {
        Intent i=new Intent();
        i.setComponent(new ComponentName(AppConfig.PKG, AppConfig.CLS));
        startActivity(i);
    }

private void invokeAPK() {
		Intent i=new Intent();
		i.setComponent(new ComponentName(AppConfig.PKG, AppConfig.CLS));
		startActivity(i);
	}

最后，不要忘记关闭数据库 呵呵
 

protected void onDestroy() {
        super.onDestroy();
        try {
            mDB.close(); // be sure to close
        } catch (Exception e) {
        }
    }