自制jar并二次打包，反射调用assets下面的jar

如题，首先自制jar并二次打包，

被打包内容：

package com.example.demo;

import android.content.Context;
import android.widget.Toast;

public class Tools {

    public void Show(Context ctx, String msg){
        Toast.makeText(ctx, msg, Toast.LENGTH_LONG).show();
    }
    
}

打包方法：http://blog.csdn.net/qq_24179679/article/details/52184596

打包完成后，将该jar重命名为xxx.jar（后面代码需要，可以自己定义名字），并复制到项目assets文件夹下

具体调用:

@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		findViewById(R.id.button1).setOnClickListener(new OnClickListener() {
			
			@Override
			public void onClick(View v) {
				// TODO Auto-generated method stub
				String path = Copy2Files(MainActivity.this);
				loadJar(MainActivity.this, path);
				try {
					if (lclass != null && obj != null) {
						Method mc = lclass.getMethod("Show",
								new Class[] {Context.class, String.class});
						mc.invoke(obj, MainActivity.this, "---xxx---");
					}
				} catch (Exception e) {
					// HdpLog.printException(e);
					e.printStackTrace();
				} 
			}
		});
	}
	
	private Object obj = null;
	private Class<?> lclass = null;
	
	public void loadJar(Context ctx, String path) {
		if (lclass == null || obj == null) {
			try {
				ClassLoader lcl = ClassLoader.getSystemClassLoader();
				DexClassLoader loader = new DexClassLoader(path, ctx
						.getDir("dex", 0).getAbsolutePath(), null, lcl);
				lclass = loader.loadClass("com.example.demo.Tools");
				Constructor<?> cons = lclass
						.getConstructor(new Class[] {});
				obj = cons.newInstance();
			} catch (Exception e) {
				 e.printStackTrace();
			}
		}
	}
	
	public String Copy2Files(Context ctx) {
		String dexName = "xxx.jar";
		File dex = new File(ctx.getFilesDir().getAbsolutePath(), "xxx.jar");
		try {
			InputStream is = ctx.getResources().getAssets().open(dexName);
			FileOutputStream fos = null;
			try {
				dex.createNewFile();
				fos = new FileOutputStream(dex);
				byte[] buffer = new byte[1024];
				int len = -1;
				while ((len = is.read(buffer)) != -1) {
					fos.write(buffer, 0, len);
				}
			} catch (Exception e) {
				 e.printStackTrace();
			} finally {
				try {
					if (fos != null) {
						fos.close();
					}
					if (is != null) {
						is.close();
					}
				} catch (IOException e) {
					 e.printStackTrace();
				}
			}
		} catch (Exception e) {
			 e.printStackTrace();
		}
		return dex.getAbsolutePath();
	}

demo地址：http://download.csdn.net/download/qq_24179679/9985816