在实际项目中。因为某些业务频繁变更而导致频繁升级client的弊病会造成较差的用户体验，而这也恰是Web App的优势，于是便衍生了一种思路。将核心的易于变更的业务封装在jar包里然后通过网络下载下来，再由android动态载入运行的方案。以改善频繁升级的毛病
--前言
本文以此为基础，扩展了一个简单的框架，教大家怎样使用该技术实现业务的动态变更升级
上效果图先：
再看看csdn code上project的项目结构
FrameExample 就是我们的demo
frame是给demo引用的链接库。也就是框架壳
FrameCore 就是核心框架包。用于被android动态载入的jar包
test文件夹展开例如以下
des.jar 经过优化的可用于动态载入的jar包
BtcMonitor.apk 測试用的apk
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httpserver界面例如以下：
demo通过frame库提供的api接口调用到framecore核心包里的详细实现代码
这样当业务详细实现有变更时，仅仅需改动framecore里的内容。然后放到网络上
framecore里能够实现一个自检測jar包版本号并自己主动更新下载jar包的功能，本例去掉了这个功能
有兴趣的童鞋能够自己尝试一下，另外本例仅仅提供了下载的接口，其他接口依据框架模板定义自行加入就可以
再贴一个核心类FrameInstance的实现：
public class FrameInstance implements IFrame{
private static final CommonLog log = LogFactory.createLog();
private static FrameInstance mInstance;
private boolean isFrameInit = false;
private Context mContext;
private Handler mJarHandler;
private DownloadJARProxy mJARProxy;
private ISimpleDownloadCallback mJARDownloadCallback;
public static synchronized FrameInstance getInstance(Context context) {
if (mInstance == null){
mInstance = new FrameInstance(context);
}
return mInstance;
}
private FrameInstance(Context context)
{
mContext = context;
mJarHandler = new Handler(){
@Override
public void handleMessage(Message msg) {
switch(msg.what){
case IHandlerMsg.ON_START:
break;
case IHandlerMsg.ON_PROGRESS:
{
int cur = msg.arg1;
int max = msg.arg2;
double rate = cur * 1.0 / max;
int value = (int) (rate * 100);
String conString = String.valueOf(value) + "%";
log.e("download jar percent:" + conString);
}
break;
case IHandlerMsg.ON_SUCCESS:
if (mJARDownloadCallback != null){
mJARDownloadCallback.onDownload(true);
}
break;
case IHandlerMsg.ON_FAIL:
if (mJARDownloadCallback != null){
mJARDownloadCallback.onDownload(false);
}
break;
case IHandlerMsg.ON_CANCEL:
break;
}
}
};
}
@Override
public boolean startFramework() {
if (isFrameInit){
return true;
}
isFrameInit = loadFrameCore();
log.e("startFramework ret = " + isFrameInit);
if (mIFrameCore != null){
mIFrameCore.startEngine(mContext);
}
return isFrameInit;
}
@Override
public boolean stopFramework() {
if (!isFrameInit){
return true;
}
if (mIFrameCore != null){
mIFrameCore.stopEngine(mContext);
}
releaseFrameCore();
isFrameInit = false;
log.e("stopFramework... ");
return true;
}
@Override
public boolean isFrameworkInit() {
return isFrameInit;
}
@Override
public boolean isFrameCoreExist() {
if (!FrameTool.hasSDCard())
return false;
File file = new File(FrameTool.getJARSavePath());
if (!file.exists()){
return false;
}
return true;
}
@Override
public boolean startDownloadFrameCore(ISimpleDownloadCallback callback) {
if (!FrameTool.hasSDCard()){
log.e("SDCard not exist!!!");
return false;
}
if (mJARProxy != null){
if (mJARProxy.isTaskRunning()){
return true;
}
}
mJARProxy = new DownloadJARProxy(mJarHandler);
mJARProxy.startDownloadTask(FrameTool.getJARURL(), FrameTool.getJARSavePath());
mJARDownloadCallback = callback;
log.e("startDownloadFrameCore...JAR_URL:" + FrameTool.getJARURL() + ", SAVE_PATH:" + FrameTool.getJARSavePath());
return true;
}
public boolean updateDownloadAPK(String url, String dstPath, IUpdateDownloadCallback callback){
if (mIUpdateTools == null){
log.e("mIUpdateTools = null!!!");
return false;
}
if (TextUtils.isEmpty(url) || TextUtils.isEmpty(dstPath)){
return false;
}
mIUpdateTools.updateDownloadAPK(url, dstPath, callback);
return true;
}
public boolean cancelDownloadAPK(){
if (mIUpdateTools == null){
log.e("mIUpdateTools = null!!!");
return false;
}
mIUpdateTools.cancelDownloadAPK();
return true;
}
public boolean checkJARVersion(){
return true;
}
public boolean installAPK(String path){
if (TextUtils.isEmpty(path)){
return false;
}
Intent i = new Intent(Intent.ACTION_VIEW);
i.setDataAndType(Uri.parse("file://" + path), "application/vnd.android.package-archive");
i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
mContext.startActivity(i);
return true;
}
private IFrameCore mIFrameCore;
private IUpdateTools mIUpdateTools;
private boolean loadFrameCore(){
// if (true){
// mIVersionTools = new VersionTools();
// mIUpdateTools = new UpdateTools();
// return true;
// }
if (!isFrameCoreExist()){
return false;
}
DexClassLoader classLoader = DexClassLoadTools.newDexClassLoader(mContext, FrameTool.getJARSavePath());
if (classLoader == null){
return false;
}
mIFrameCore = ClassFactory.newFrameCore(classLoader);
if (mIFrameCore == null){
return false;
}
mIUpdateTools = ClassFactory.newUpdateTools(classLoader);
return true;
}
private void releaseFrameCore(){
mIFrameCore = null;
mIUpdateTools = null;
}
private static class ClassFactory{
public static IFrameCore newFrameCore(DexClassLoader classLoader){
IFrameCore object = null;
Class cls = newFrameCoreClass(classLoader, "com.lance.framecore.externex.FrameCore");
if (cls != null){
try {
object = (IFrameCore) cls.newInstance();
} catch (InstantiationException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
}
}
return object;
}
public static IUpdateTools newUpdateTools(DexClassLoader classLoader){
IUpdateTools object = null;
Class cls = newFrameCoreClass(classLoader, "com.lance.framecore.externex.UpdateTools");
if (cls != null){
try {
object = (IUpdateTools) cls.newInstance();
} catch (InstantiationException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
}
}
return object;
}
public static Class newFrameCoreClass(DexClassLoader classLoader, String className){
Class libProviderClazz = null;
try {
libProviderClazz = classLoader.loadClass(className);
} catch (Exception exception) {
exception.printStackTrace();
}
return libProviderClazz;
}
}
public static class FrameTool{
private final static String JAR_URL = "http://192.168.1.101/jar/des.jar";
public static boolean hasSDCard() {
String status = Environment.getExternalStorageState();
if (!status.equals(Environment.MEDIA_MOUNTED)) {
return false;
}
return true;
}
public static String getRootFilePath() {
if (hasSDCard()) {
return Environment.getExternalStorageDirectory().getAbsolutePath() + "/";
} else {
return Environment.getDataDirectory().getAbsolutePath() + "/data/";
}
}
public static String getJARURL(){
return JAR_URL;
}
public static String getJARSavePath(){
return getRootFilePath() + "FrameCore.jar";
}
}
private static class DexClassLoadTools{
public static DexClassLoader newDexClassLoader(Context context, String jarPath){
final File optimizedDexOutputPath = new File(jarPath);
if (!optimizedDexOutputPath.exists()){
return null;
}
File file = context.getDir("osdk", 0);
log.e("getDir:" + file.getAbsolutePath());
DexClassLoader cl = new DexClassLoader(optimizedDexOutputPath.getAbsolutePath(),
file.getAbsolutePath(),
null,
context.getClassLoader());
return cl;
}
}
@Override
public boolean deleteFrameCore() {
log.e("deleteFrameCore");
if (!isFrameCoreExist()){
log.e("framecore.jar is not exist:" + FrameTool.getJARSavePath());
return false;
}
FileTools.deleteDirectory(FrameTool.getJARSavePath());
return true;
}
@Override
public FrameCoreInfo getFrameCoreInfo() {
try {
if (mIFrameCore == null){
return new FrameCoreInfo();
}
return mIFrameCore.getFrameCoreInfo(mContext);
} catch (Exception e) {
e.printStackTrace();
return new FrameCoreInfo();
}
}
}值得注意的是
在导出framecore时无需导出com.lance.framecore.extern包下代码，否则载入时会出现反复定义错误
同一时候要保持framecoreproject和frameproject该包代码的一致，在扩展接口时把对应接口写在这个包下就可以
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其他的没啥好说的了，自个儿download代码看吧以下附上code地址：https://code.csdn.net/geniuseoe2012/dynamicjar
假设童鞋们认为本文实用，最好还是关注我的code主页：https://code.csdn.net/geniuseoe2012
以后一些博文相关的demo会放在上面，这样大家就不用耗下载积分了。同一时候便于代码更正
很多其它开源项目可关注我的github主页：https://github.com/geniusgithub