动态加载so

LoadNativeLibraryUtils.java

package com.baidu.common.sofile;

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

import com.baidu.common.LogUtil;

import java.io.File;
import java.io.IOException;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;

public class LoadNativeLibraryUtils {
    private static final String TAG = "LoadNativeLibraryUtils";

    public static final String SO_CACHE_DIR = "jniLibs";

    public static void injectDir(Context context) {
        File dir = context.getDir(SO_CACHE_DIR, Context.MODE_PRIVATE);
        ClassLoader classLoader = context.getApplicationContext().getClassLoader();
        try {
            installNativeLibraryPath(classLoader, dir);
        } catch (Throwable throwable) {
            // ignore
        }
    }

    private static void installNativeLibraryPath(ClassLoader classLoader, File folder)
            throws Throwable {
        if (folder == null || !folder.exists()) {
            LogUtil.e(TAG, "installNativeLibraryPath, folder:" + folder + " is illegal");
            return;
        }
        // android o sdk_int 26
        // for android o preview sdk_int 25
        if ((Build.VERSION.SDK_INT == 25 && Build.VERSION.PREVIEW_SDK_INT != 0)
                || Build.VERSION.SDK_INT > 25) {
            try {
                V25.install(classLoader, folder);
                return;
            } catch (Throwable throwable) {
                // install fail, try to treat it as v23
                // some preview N version may go here
                LogUtil.e(TAG, "installNativeLibraryPath, v25 fail, sdk:" + Build.VERSION.SDK_INT + " , error:" +
                        throwable.getMessage());
                V23.install(classLoader, folder);
            }
        } else if (Build.VERSION.SDK_INT >= 23) {
            try {
                V23.install(classLoader, folder);
            } catch (Throwable throwable) {
                // install fail, try to treat it as v14
                LogUtil.e(TAG,
                        "installNativeLibraryPath, v23 fail, sdk:" + Build.VERSION.SDK_INT + " , error:" + throwable
                                .getMessage());

                V14.install(classLoader, folder);
            }
        } else if (Build.VERSION.SDK_INT >= 14) {
            V14.install(classLoader, folder);
        } else {
            V4.install(classLoader, folder);
        }
    }

    private static final class V4 {
        private static void install(ClassLoader classLoader, File folder) throws Throwable {
            String addPath = folder.getPath();
            Field pathField = ReflectUtil.findField(classLoader, "libPath");
            StringBuilder libPath = new StringBuilder((String) pathField.get(classLoader));
            libPath.append(':').append(addPath);
            pathField.set(classLoader, libPath.toString());

            Field libraryPathElementsFiled = ReflectUtil.findField(classLoader, "libraryPathElements");
            List<String> libraryPathElements = (List<String>) libraryPathElementsFiled.get(classLoader);
            libraryPathElements.add(0, addPath);
            libraryPathElementsFiled.set(classLoader, libraryPathElements);
        }
    }

    private static final class V14 {
        private static void install(ClassLoader classLoader, File folder) throws Throwable {
            Field pathListField = ReflectUtil.findField(classLoader, "pathList");
            Object dexPathList = pathListField.get(classLoader);

            ReflectUtil.expandFieldArray(dexPathList, "nativeLibraryDirectories", new File[] {folder});
        }
    }

    private static final class V23 {
        private static void install(ClassLoader classLoader, File folder) throws Throwable {
            Field pathListField = ReflectUtil.findField(classLoader, "pathList");
            Object dexPathList = pathListField.get(classLoader);

            Field nativeLibraryDirectories = ReflectUtil.findField(dexPathList, "nativeLibraryDirectories");

            List<File> libDirs = (List<File>) nativeLibraryDirectories.get(dexPathList);
            libDirs.add(0, folder);
            Field systemNativeLibraryDirectories =
                    ReflectUtil.findField(dexPathList, "systemNativeLibraryDirectories");
            List<File> systemLibDirs = (List<File>) systemNativeLibraryDirectories.get(dexPathList);
            Method makePathElements =
                    ReflectUtil.findMethod(dexPathList, "makePathElements", List.class, File.class, List.class);
            ArrayList<IOException> suppressedExceptions = new ArrayList<>();
            libDirs.addAll(systemLibDirs);
            Object[] elements = (Object[]) makePathElements.
                    invoke(dexPathList, libDirs, null, suppressedExceptions);
            Field nativeLibraryPathElements = ReflectUtil.findField(dexPathList, "nativeLibraryPathElements");
            nativeLibraryPathElements.setAccessible(true);
            nativeLibraryPathElements.set(dexPathList, elements);
        }
    }

    private static final class V25 {
        private static void install(ClassLoader classLoader, File folder) throws Throwable {
            Field pathListField = ReflectUtil.findField(classLoader, "pathList");
            Object dexPathList = pathListField.get(classLoader);

            Field nativeLibraryDirectories = ReflectUtil.findField(dexPathList, "nativeLibraryDirectories");

            List<File> libDirs = (List<File>) nativeLibraryDirectories.get(dexPathList);
            libDirs.add(0, folder);
            Field systemNativeLibraryDirectories =
                    ReflectUtil.findField(dexPathList, "systemNativeLibraryDirectories");
            List<File> systemLibDirs = (List<File>) systemNativeLibraryDirectories.get(dexPathList);
            Method makePathElements =
                    ReflectUtil.findMethod(dexPathList, "makePathElements", List.class);
            libDirs.addAll(systemLibDirs);
            Object[] elements = (Object[]) makePathElements.
                    invoke(dexPathList, libDirs);
            Field nativeLibraryPathElements = ReflectUtil.findField(dexPathList, "nativeLibraryPathElements");
            nativeLibraryPathElements.setAccessible(true);
            nativeLibraryPathElements.set(dexPathList, elements);
        }
    }

}