http://www.cnblogs.com/over140/archive/2011/11/23/2259367.html
加载jar
boolean bool = new File("/sdcard/test.jar").exists();DexClassLoader cl = new DexClassLoader("/sdcard/test.jar", this.getCacheDir().getAbsolutePath(), null, this.getClassLoader());try {Class<?> c = cl.loadClass("HelloWorld");Object obj = c.newInstance();Method method = c.getMethod("getHelloWord", null);String s = (String) method.invoke(obj, null);TextView tv = (TextView)findViewById(R.id.tv);tv.setText(s);} catch (ClassNotFoundException | NoSuchMethodException | IllegalAccessException | IllegalArgumentException | InvocationTargetException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (InstantiationException e) {// TODO Auto-generated catch blocke.printStackTrace();}
不要忘记：
将jar优化时应该重新成jar(jar->dex->jar)，如果如下命令：
dx --dex --output=test.jar dynamic.jar
加载未安装APK中的类
public class MainActivity extends ActionBarActivity {@SuppressLint("NewApi")@SuppressWarnings("unused")@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);boolean bool = new File("/sdcard/test.apk").exists();DexClassLoader cl = new DexClassLoader("/sdcard/test.apk", this.getCacheDir().getAbsolutePath(), null, this.getClassLoader());try {Class<?> c = cl.loadClass("com.example.testdexclassloaderloadapk.MainActivity");Object obj = c.newInstance();Method method = c.getMethod("getHelloWord", null);String s = (String) method.invoke(obj, null);TextView tv = (TextView)findViewById(R.id.tv);tv.setText(s);} catch (ClassNotFoundException | NoSuchMethodException | IllegalAccessException | IllegalArgumentException | InvocationTargetException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (InstantiationException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (Exception e) {// TODO Auto-generated catch blocke.printStackTrace();}}
}
注意：
1.由于是使用反射，无法取得Context，也就是TestBActivity与普通的类毫无区别，没有生命周期。
2.做实验是出现了： Class ref in pre-verified class resolved to unexpected implementation 错误
查看：http://blog.csdn.net/berber78/article/details/41721877
原因是 两个工程引用了同样的 appcompat_v7 工程
大神之作 dl 动态加载架构：
https://github.com/singwhatiwanna/dynamic-load-apk
