Android 反射实战
前面做了很多个demo去学习如何反射字段,方法,代理之类的等等,有一些给了实际的应用,有一些没有,看起来似乎没有什么实际价值,所以现在给出一个实战,开发条件需要的是一个jar包,这里以com.qti.snapdragon.sdk.display.jar的jar为例.调试设备以Oneplus二代旗舰机为例,jar放在Oneplus二代手机的/system/framework/目录下,普通读者可以放到其他目录下,比如sdcard/下.
下面开始实施实际操作过程:
<1> : 新建一个Android工程,工程树如下:
<2> : 布局文件中放三个按钮,并且在OneplusMainActivity.java中增加对应的事件处理:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<Button
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="hello"
android:id="@+id/button"/>
<Button
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="field"
android:id="@+id/fieldbutton"/>
<Button
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="listener"
android:id="@+id/listenerbutton"/>
</LinearLayout>
注意:
Manifest.xml文件中还需要增加一个权限,因为jar会检查它自己设定的权限的:
<uses-permission android:name="com.qti.snapdragon.sdk.permission.DISPLAY_SETTINGS" />
多说两句,权限不一定只有android系统才有,自己也可以自定义权限限制,然后在被第三方使用的时候,检查第三方是否具备这个权限,检查调用:
Context.checkCallingOrSelfPermission(String);
参数是权限的名字,本案例中的jar检查如下(反编译jar看到的源文件所得),发现jar中会检查调用jar包接口的第三方是否具有权限:
从jar反编译出来的信息可以知道,他会检查调用jar包第三方应用的权限设定的,所以必须在app中添加上面的权限.
<3> : 主体程序如下:
package com.oneplus.oneplusdisplayjardemo;
import java.io.File;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import dalvik.system.DexClassLoader;
import android.app.Activity;
import android.app.Application;
import android.content.Context;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
/**
* @author : zhibao.liu
* @complay : oneplus.Inc
* @Date : 2015/11/30
*
* */
public class OneplusMainActivity extends Activity implements OnClickListener {
private static final String TAG = "OneplusMainActivity";
//下面是需要反射对应的包和类等信息
private final static String PACKAGENAME = "com.qti.snapdragon.sdk.display.ColorManager";
private final static String PACKAGEFIELDNAME = "com.qti.snapdragon.sdk.display.ColorManager$DCM_DISPLAY_TYPE";
private final static String PACKAGELISTENERNAME = "com.qti.snapdragon.sdk.display.ColorManager$ColorManagerListener";
private Button mButton;
private Button mFieldButton;
private Button mListenerButton;
private Context mContext;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.oneplus_main);
mButton = (Button) findViewById(R.id.button);
mFieldButton = (Button) findViewById(R.id.fieldbutton);
mListenerButton = (Button) findViewById(R.id.listenerbutton);
mButton.setOnClickListener(this);
mFieldButton.setOnClickListener(this);
mListenerButton.setOnClickListener(this);
mContext = OneplusMainActivity.this;
}
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
int id = v.getId();
switch (id) {
case R.id.button:
// OneplusDisplaySDKReflex.OneplusReflex(PACKAGENAME,mContext);
// OneplusDisplaySDKReflex.OneplusReflexClass(PACKAGENAME);
OneplusReflex(PACKAGENAME, "getInstance");
break;
case R.id.fieldbutton:
OneplusFieldReflex(PACKAGEFIELDNAME, "DISP_PRIMARY");
break;
case R.id.listenerbutton:
//这个才是我们的重点,前面两个只是测试包信息.
//下面才是连接包并且工作的.
OneplusReflexListener(PACKAGELISTENERNAME);
break;
}
}
public void OneplusReflexListener(String packagenamelistener) {
//下面的这个环境,是直接读取/system/framework/目录了
//其实它本身已经系统jar路径下,只需要包名就可以反射了.
//下面只是给出一个更加通用的,无论是Android系统的,还是将来第三方的,放在任何地方,只需要调整这个路径就可以了.
String dexPath = Environment.getRootDirectory().getPath()
+ File.separator + "framework" + File.separator
+ "com.qti.snapdragon.sdk.display.jar";
File file = new File(dexPath);
if (!file.exists()) {
return;
}
String dexOutputDirs = Environment.getExternalStorageDirectory()
.toString(); // this is not access permission to read/write
// random file
final File optimizedDexOutputPath = getDir("outdex", 0);
DexClassLoader cl = new DexClassLoader(dexPath,
optimizedDexOutputPath.getAbsolutePath(), null,
getClassLoader());
try {
Class clazzlis = cl.loadClass(packagenamelistener);
Object listener = Proxy.newProxyInstance(clazzlis.getClassLoader(),
new Class<?>[] { clazzlis }, new InvocationHandler() {
@Override
public Object invoke(Object proxy, Method method,
Object[] args) throws Throwable {
// TODO Auto-generated method stub
//运行了一个代理
//下面反射connect方法,并且调用,如果连接成功
//就会通过这个回调调用下面的逻辑了.
Log.i(TAG,
"connect to service sucessfully , todo your work here !");
// following continue initial
/* OneplusReflex(PACKAGENAME,"getInstance"); */
return null;
}
});
Class clazzcm = cl.loadClass(PACKAGENAME);
Object object;
try {
/*
* start up connecting to qual service jar
*/
Method conMethod = clazzcm.getDeclaredMethod("connect",
new Class[] { Context.class, clazzlis });
conMethod.setAccessible(true);
try {
conMethod.invoke(/* object */null, new Object[] { mContext,
listener });
} catch (IllegalAccessException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IllegalArgumentException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InvocationTargetException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} catch (NoSuchMethodException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void OneplusReflex(String packagename, String methodname) {
String dexPath = Environment.getRootDirectory().getPath()
+ File.separator + "framework" + File.separator
+ "com.qti.snapdragon.sdk.display.jar";
File file = new File(dexPath);
if (!file.exists()) {
return;
}
String dexOutputDirs = Environment.getExternalStorageDirectory()
.toString(); // this is not access permission to read/write
// random file
final File optimizedDexOutputPath = getDir("outdex", 0);
DexClassLoader cl = new DexClassLoader(dexPath,
optimizedDexOutputPath.getAbsolutePath(), null,
getClassLoader());
try {
Class clazz = cl.loadClass(packagename);// Class.forName(packagename);
Method methods[] = clazz.getDeclaredMethods();
try {
Class DIS_TYPE = OneplusFeildTypeReflex(PACKAGENAME,
"DCM_DISPLAY_TYPE");
System.out.println("class type : " + DIS_TYPE.toString());
Method method = clazz.getDeclaredMethod(methodname,
new Class<?>[] { Application.class, Context.class,
DIS_TYPE });
try {
Object ret = OneplusFieldReflex(PACKAGEFIELDNAME,
"DISP_PRIMARY");
method.setAccessible(true);
method.invoke(null, new Object[] { this.getApplication(),
OneplusMainActivity.this, ret });
/*
* after init colormanager try to set value it to system
*/
Method methodset = clazz.getDeclaredMethod(
"setColorBalance", new Class[] { int.class });
methodset.setAccessible(true);
try {
methodset.invoke(clazz.newInstance(),
new Object[] { 56 });
} catch (InstantiationException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} catch (IllegalAccessException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IllegalArgumentException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InvocationTargetException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} catch (NoSuchMethodException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public Class OneplusFeildTypeReflex(String packagename, String fieldname) {
String dexPath = Environment.getRootDirectory().getPath()
+ File.separator + "framework" + File.separator
+ "com.qti.snapdragon.sdk.display.jar";
File file = new File(dexPath);
if (!file.exists()) {
return null;
}
String dexOutputDirs = Environment.getExternalStorageDirectory()
.toString(); // this is not access permission to read/write
// random file
final File optimizedDexOutputPath = getDir("outdex", 0);
DexClassLoader cl = new DexClassLoader(dexPath,
optimizedDexOutputPath.getAbsolutePath(), null,
getClassLoader());
try {
Class clazz = cl.loadClass(PACKAGEFIELDNAME);
return clazz;
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
public Object OneplusFieldReflex(String packagename, String fieldname) {
String dexPath = Environment.getRootDirectory().getPath()
+ File.separator + "framework" + File.separator
+ "com.qti.snapdragon.sdk.display.jar";
File file = new File(dexPath);
if (!file.exists()) {
return null;
}
String dexOutputDirs = Environment.getExternalStorageDirectory()
.toString(); // this is not access permission to read/write
// random file
final File optimizedDexOutputPath = getDir("outdex", 0);
DexClassLoader cl = new DexClassLoader(dexPath,
optimizedDexOutputPath.getAbsolutePath(), null,
getClassLoader());
try {
Class clazz = cl.loadClass(packagename);
Object obj = null;
Field fields[] = clazz.getDeclaredFields();
for (int i = 0; i < fields.length; i++) {
fields[i].setAccessible(true);
try {
Field field = clazz.getDeclaredField(fieldname);
field.setAccessible(true);
try {
Object ret = null;
ret = field.get(null);
if (ret == null) {
continue;
}
System.out.println("value : " + ret.toString());
return ret;
} catch (IllegalAccessException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IllegalArgumentException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} catch (NoSuchFieldException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
}
大致的解释放在上面的程序中,通过上面的程序达到一个综合的运用,运行结果如下:
从结果看的出来,我们通过先反射connect方法去连接服务,连接成功后,回调回来,这个通过代理来实现,然后正式操作的程序放在代理里面开始执行或者初始化.
基本思路如下: