Android为TV端助力之QQ空间热更新技术

直接上代码

package com.enjoy.patch;

import android.content.Context;
import android.os.Build;
import android.util.Log;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;

public class EnjoyFix {

    private static final String TAG = "EnjoyFix";

    private static File initHack(Context context) {

        File hackDir = context.getDir("hack", Context.MODE_PRIVATE);
        File hackFile = new File(hackDir, "hack.jar");
        if (!hackFile.exists()) {
            BufferedInputStream is = null;
            BufferedOutputStream os = null;
            try {
                is = new BufferedInputStream(context.getAssets().open("hack" +
                        ".jar"));
                os = new BufferedOutputStream(new FileOutputStream(hackFile));
                byte[] buffer = new byte[4096];
                int len;
                while ((len = is.read(buffer)) != -1) {
                    os.write(buffer, 0, len);
                }
            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                if (is != null){
                    try {
                        is.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
                if (os != null){
                    try {
                        os.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }
        }
        return hackFile;

    }

    public static void installPatch(Context context, File patch) {
        File hackFile = initHack(context);
        ClassLoader classLoader = context.getClassLoader();
        List<File> files = new ArrayList<>();
        if (patch.exists()) {
            files.add(patch);
        }
        files.add(hackFile);
        File dexOptDir = context.getCacheDir();
        try {
            Log.i("TAG","Build.VERSION.SDK_INT"+Build.VERSION.SDK_INT);
            //23 6.0及以上
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
                V23.install(classLoader, files, dexOptDir);
            } else if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
                V19.install(classLoader, files, dexOptDir); //4.4以上
            } else {  // >= 14
                V14.install(classLoader, files, dexOptDir);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private static final class V23 {

        private static void install(ClassLoader loader, List<File> additionalClassPathEntries,
                                    File optimizedDirectory)
                throws IllegalArgumentException, IllegalAccessException,
                NoSuchFieldException, InvocationTargetException, NoSuchMethodException,
                IOException {
            //找到 pathList
            Field pathListField = SharedReflectUtils.findField(loader, "pathList");
            Object dexPathList = pathListField.get(loader);

            ArrayList<IOException> suppressedExceptions = new ArrayList<>();
            // 从 pathList找到 makePathElements 方法并执行
            // 得到补丁创建的 Element[]
            Object[] objects = makePathElements(dexPathList,
                    new ArrayList<>(additionalClassPathEntries), optimizedDirectory,
                    suppressedExceptions);

            //将原本的 dexElements 与 makePathElements生成的数组合并
            SharedReflectUtils.expandFieldArray(dexPathList, "dexElements", objects);
            if (suppressedExceptions.size() > 0) {
                for (IOException e : suppressedExceptions) {
                    Log.w(TAG, "Exception in makePathElement", e);
                    throw e;
                }

            }
        }

        /**
         * 把dex转化为Element数组
         */
        private static Object[] makePathElements(
                Object dexPathList, ArrayList<File> files, File optimizedDirectory,
                ArrayList<IOException> suppressedExceptions)
                throws IllegalAccessException, InvocationTargetException, NoSuchMethodException {
            //通过阅读android6、7、8、9源码，都存在makePathElements方法
            Method makePathElements = SharedReflectUtils.findMethod(dexPathList, "makePathElements",
                    List.class, File.class,
                    List.class);
            return (Object[]) makePathElements.invoke(dexPathList, files, optimizedDirectory,
                    suppressedExceptions);
        }
    }

    private static final class V19 {

        private static void install(ClassLoader loader, List<File> additionalClassPathEntries,
                                    File optimizedDirectory)
                throws IllegalArgumentException, IllegalAccessException,
                NoSuchFieldException, InvocationTargetException, NoSuchMethodException,
                IOException {
            Field pathListField = SharedReflectUtils.findField(loader, "pathList");
            Object dexPathList = pathListField.get(loader);
            ArrayList<IOException> suppressedExceptions = new ArrayList<IOException>();
            SharedReflectUtils.expandFieldArray(dexPathList, "dexElements",
                    makeDexElements(dexPathList,
                            new ArrayList<File>(additionalClassPathEntries), optimizedDirectory,
                            suppressedExceptions));
            if (suppressedExceptions.size() > 0) {
                for (IOException e : suppressedExceptions) {
                    Log.w(TAG, "Exception in makeDexElement", e);
                    throw e;
                }
            }
        }

        private static Object[] makeDexElements(
                Object dexPathList, ArrayList<File> files, File optimizedDirectory,
                ArrayList<IOException> suppressedExceptions)
                throws IllegalAccessException, InvocationTargetException, NoSuchMethodException {
            Method makeDexElements = SharedReflectUtils.findMethod(dexPathList, "makeDexElements",
                    ArrayList.class, File.class,
                    ArrayList.class);

            return (Object[]) makeDexElements.invoke(dexPathList, files, optimizedDirectory,
                    suppressedExceptions);
        }
    }

    /**
     * 14, 15, 16, 17, 18.
     */
    private static final class V14 {

        private static void install(ClassLoader loader, List<File> additionalClassPathEntries,
                                    File optimizedDirectory)
                throws IllegalArgumentException, IllegalAccessException,
                NoSuchFieldException, InvocationTargetException, NoSuchMethodException {

            Field pathListField = SharedReflectUtils.findField(loader, "pathList");
            Object dexPathList = pathListField.get(loader);

            SharedReflectUtils.expandFieldArray(dexPathList, "dexElements",
                    makeDexElements(dexPathList,
                            new ArrayList<File>(additionalClassPathEntries), optimizedDirectory));
        }

        private static Object[] makeDexElements(
                Object dexPathList, ArrayList<File> files, File optimizedDirectory)
                throws IllegalAccessException, InvocationTargetException,
                NoSuchMethodException {
            Method makeDexElements =
                    SharedReflectUtils.findMethod(dexPathList, "makeDexElements", ArrayList.class,
                            File.class);
            return (Object[]) makeDexElements.invoke(dexPathList, files, optimizedDirectory);
        }
    }

}
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package com.enjoy.patch;

import java.lang.reflect.Array;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.Arrays;

/**
 * 反射工具类
 */
public class SharedReflectUtils {

    /**
     * 从 instance 到其父类 找 name 属性
     *
     * @param instance
     * @param name
     * @return
     * @throws NoSuchFieldException
     */
    public static Field findField(Object instance, String name) throws NoSuchFieldException {
        for (Class<?> clazz = instance.getClass(); clazz != null; clazz = clazz.getSuperclass()) {
            try {
                //查找当前类的 属性(不包括父类)
                Field field = clazz.getDeclaredField(name);

                if (!field.isAccessible()) {
                    field.setAccessible(true);
                }
                return field;
            } catch (NoSuchFieldException e) {
                // ignore and search next
            }
        }
        throw new NoSuchFieldException("Field " + name + " not found in " + instance.getClass());
    }

    /**
     * 从 instance 到其父类 找  name 方法
     *
     * @param instance
     * @param name
     * @return
     * @throws NoSuchFieldException
     */
    public static Method findMethod(Object instance, String name, Class<?>... parameterTypes)
            throws NoSuchMethodException {
        for (Class<?> clazz = instance.getClass(); clazz != null; clazz = clazz.getSuperclass()) {
            try {
                Method method = clazz.getDeclaredMethod(name, parameterTypes);

                if (!method.isAccessible()) {
                    method.setAccessible(true);
                }

                return method;
            } catch (NoSuchMethodException e) {
                // ignore and search next
            }
        }
        throw new NoSuchMethodException("Method "
                + name
                + " with parameters "
                + Arrays.asList(parameterTypes)
                + " not found in " + instance.getClass());
    }

    /**
     * @param instance
     * @param fieldName
     * @param fixs      补丁的Element数组
     * @throws NoSuchFieldException
     * @throws IllegalArgumentException
     * @throws IllegalAccessException
     */
    public static void expandFieldArray(Object instance, String fieldName, Object[] fixs)
            throws NoSuchFieldException, IllegalArgumentException, IllegalAccessException {
        //拿到 classloader中的dexelements 数组
        Field jlrField = findField(instance, fieldName);
        //old Element[]
        Object[] old = (Object[]) jlrField.get(instance);

        //合并后的数组
        Object[] newElements = (Object[]) Array.newInstance(old.getClass().getComponentType(),
                old.length + fixs.length);

        // 先拷贝新数组
        System.arraycopy(fixs, 0, newElements, 0, fixs.length);
        System.arraycopy(old, 0, newElements, fixs.length, old.length);

        //修改 classLoader中 pathList的 dexelements
        jlrField.set(instance, newElements);
    }

}