andorid动态加载jar

雨点打透心脏的1/2处 2022-06-10 05:13 196阅读 0赞

最近研究了下android动态加载jar,下面总结下。

这里使用的eclipse开发测试。

网上介绍原理的很多，请自行百度.

首先需要创建两个工程，一个是生成需要的jar的工程，一个是实际测试用的工程

接口类工程中建两个包如下图:

![20170810175307033][]

IDynamic.java内容如下:

package com.dynamic.interfaces;  
    import android.app.Activity;  
    
    public interface IDynamic {  
    	public int cal(int a,int b);
    	public String test();
    }

Dynamic.java内容如下:

package com.dynamic.impl;
    
    import android.app.Activity;
    import android.util.Log;
    import android.widget.Toast;
    
    import com.dynamic.interfaces.IDynamic;
    
    public class Dynamic implements IDynamic{
    	@Override
    	public int cal(int a, int b) {
    		// TODO Auto-generated method stub
    		return (a * b);
    	}
    
    	@Override
    	public String test() {
    		// TODO Auto-generated method stub
    		return "this is Dynamic test1";
    	}
    }

然后分别导出这两个文件为jar  
选中IDynamic.java右键点击导出JAR FILE,导出文件名为jarint.jar  
注意导出的时候只需要选这一个文件  
同样选中Dynamic.java右键点击导出JAR FILE,导出文件名为jartest.jar  
注意导出的时候只需要选这一个文件  
将jartest.jar拷贝到sdk目录中的build-tools中的对应的api目录中，例如我的是  
build-tools\\22.0.1  
然后在命令行进行这个目录:

执行dx --dex --out dex.jar jartest.jar如下图(注意:中间的--为两个"-")

![20170810180403627][]

然后将生成的dex.jar push到系统/sdcard目录下(,我的这个sdcard目录为内部存储挂载路径,我测试的是有root权限的所以可以这么整，没权限的还是通过TF卡)  
这两个jar过会需要使用  
实际测试应用内容如下:

![20170810175919153][]

需要将上面导出的jarint.jar放在这个工程的libs目录下  
Main.java内容如下:

package com.example.jartest;
    
    import java.io.File;
    import java.util.List;
    
    import com.dynamic.interfaces.IDynamic;
    
    import android.app.Activity;
    import android.content.Intent;
    import android.content.pm.ActivityInfo;
    import android.content.pm.PackageManager;
    import android.content.pm.ResolveInfo;
    import android.os.Bundle;
    import android.util.Log;
    import android.view.View;
    import android.view.View.OnClickListener;
    import android.widget.Button;
    import dalvik.system.DexClassLoader;
    import dalvik.system.PathClassLoader;
    
    public class Main extends Activity {
    	public final static String TAG = "jartest";
    	final private String BasePath = "/sdcard";//"/storage/sdcard1";
    	private IDynamic lib;  
    	String jarpath = BasePath + "/dex.jar";
    	String packname = "com.dynamic.impl";
    	private Button mytest;
    	@Override
    	protected void onCreate(Bundle savedInstanceState) {
    		super.onCreate(savedInstanceState);
    		setContentView(R.layout.main);
    		mytest = (Button)findViewById(R.id.mytest);
    		
    		Log.d(TAG, "jarpath: " + jarpath);
    		File jar = new File(jarpath);
    		if(!jar.exists()) {
    			Log.d(TAG, "++jar file not found");
    			return;
    		}
    		
    		mytest.setOnClickListener(new OnClickListener(){
    			@Override
    			public void onClick(View v) {
    				// TODO Auto-generated method stub
    				DexLoader();
    				//PathLoader();
    			}
    		});
    	}
    	
    	private void PathLoader() {
    		Intent intent = new Intent(packname, null); 
    		PackageManager pm = getPackageManager();    
    		List<ResolveInfo> resolveinfoes =  pm.queryIntentActivities(intent, 0);    
    		Log.d(TAG, "list: " + resolveinfoes.size());
    		ActivityInfo actInfo = resolveinfoes.get(0).activityInfo;    
    		String apkPath = actInfo.applicationInfo.sourceDir;    
    		String libPath = actInfo.applicationInfo.nativeLibraryDir;    
    		Log.d(TAG, "apkPath: " + apkPath);
    		Log.d(TAG, "libPath: " + libPath);
            PathClassLoader pcl = new PathClassLoader(apkPath,libPath,this.getClassLoader()); 
            try {
    			Class libProviderClazz = pcl.loadClass("com.dynamic.impl.Dynamic");
    			lib = (IDynamic)libProviderClazz.newInstance();
                if(lib != null){  
                	Log.d(TAG, "---:" + lib.test());
                	Log.d(TAG, "---cal :" + lib.cal(1,2));
                }  else
                	Log.d(TAG, "++lib is null");
    		} catch (ClassNotFoundException e) {
    			// TODO Auto-generated catch block
    			Log.d(TAG, e.getMessage());
    			e.printStackTrace();
    		} catch (InstantiationException e) {
    			// TODO Auto-generated catch block
    			Log.d(TAG, e.getMessage());
    			e.printStackTrace();
    		} catch (IllegalAccessException e) {
    			// TODO Auto-generated catch block
    			Log.d(TAG, e.getMessage());
    			e.printStackTrace();
    		}
    	}
    	
    	private void DexLoader() {
    		File dexOutputDir = this.getDir("dex", 0);
    		String tmpPath = dexOutputDir.getAbsolutePath();
    		Log.d(TAG," tmpPath: " + tmpPath);
    		DexClassLoader cl = new DexClassLoader(jarpath,tmpPath,null,this.getClassLoader());
    		try {
    			Class libProviderClazz = cl.loadClass("com.dynamic.impl.Dynamic");
    			lib = (IDynamic)libProviderClazz.newInstance();  
                if(lib != null){  
                	Log.d(TAG, "---:" + lib.test());
                	Log.d(TAG, "---cal :" + lib.cal(1,2));
                }  else
                	Log.d(TAG, "++lib is null");
    		} catch (ClassNotFoundException e) {
    			// TODO Auto-generated catch block
    			Log.d(TAG, e.getMessage());
    			e.printStackTrace();
    		} catch (InstantiationException e) {
    			// TODO Auto-generated catch block
    			Log.d(TAG, e.getMessage());
    			e.printStackTrace();
    		} catch (IllegalAccessException e) {
    			// TODO Auto-generated catch block
    			Log.d(TAG, e.getMessage());
    			e.printStackTrace();
    		}
    	}
    }

注意：使用DexLoader即使用DexClassLoader类加载，如果dex.jar是放在内部存储路径或者外部存储中，需要加相应的权限:

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
        <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />

如果使用PathLoader即使用PathClassLoader加载，需要在接口类我的为JarInterface的AndroidManifest.xml中增加对应的包名:

修改后如下:

不然调用不会成功

相关源码下载地址：[http://download.csdn.net/download/hclydao/9928304][http_download.csdn.net_download_hclydao_9928304]

本来没准备要下载分的，但是没看到０分的选项，最少只有1分.  
参考文章: [http://blog.csdn.net/jiangwei0910410003/article/details/17679823][http_blog.csdn.net_jiangwei0910410003_article_details_17679823]

[20170810175307033]: /images/20220610/7ef203a5e8ed4e3c866a9edfceb8fe38.png
[20170810180403627]: /images/20220610/b956540e1e1e46939bfa841d13ebfffe.png
[20170810175919153]: /images/20220610/e06c0fc5597b4273b0ceb59e482441ff.png
[http_download.csdn.net_download_hclydao_9928304]: http://download.csdn.net/download/hclydao/9928304
[http_blog.csdn.net_jiangwei0910410003_article_details_17679823]: http://blog.csdn.net/jiangwei0910410003/article/details/17679823