Android外掛化（二）：使用DexClassLoader動態載入assets中的apk

yangxi_001發表於2016-01-08

轉自：http://blog.csdn.net/nupt123456789/article/details/50411581

簡介

上一篇部落格講到，我們可以使用MultiDex.java載入離線的apk檔案。需要注意的是，apk中的類是載入到當前的PathClassLoader當中的，如果apk檔案過多，可能會出現ANR的情況。那麼，我們能不能使用DexClassLoader載入apk呢？當然是可以的！首先看一下Doc文件.

<code class="language-html hljs  has-numbering" style="display: block; padding: 0px; background-color: transparent; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-top-left-radius: 0px; border-top-right-radius: 0px; border-bottom-right-radius: 0px; border-bottom-left-radius: 0px; word-wrap: normal; background-position: initial initial; background-repeat: initial initial;">A class loader that loads classes from .jar and .apk files containing a classes.dex entry. This can be used to execute code not installed as part of an application.</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; background-color: rgb(238, 238, 238); top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right;"><li style="box-sizing: border-box; padding: 0px 5px;">1</li></ul>

也就是說，DexClassLoader可以載入一個含有classes.dex檔案的壓縮包，既可以是jar也可以是apk。那麼載入一個離線的apk檔案需要注意哪些呢？

1.DexClassLoader的構造方法：
DexClassLoader(String dexPath, String optimizedDirectory, String libraryPath, ClassLoader parent)
2.私有目錄
This class loader requires an application-private, writable directory to cache optimized classes.

瞭解到上述兩點，我們就可以根據DexClassLoader所需要的引數，動態載入assets中的apk了。

原始碼

BundleClassLoaderManager

該類主要是負責管理這些DexClassLoader的，首先，我們定義了一個叫做BundleDexClassLoader的類，它繼承自DexClassLoader，用於載入離線的apk檔案。每一個apk檔案對應一個BundleDexClassLoader,而BundleClassLoaderManager則儲存了一個List,在載入的時候，用於查詢類。具體程式碼如下：

<code class="language-java hljs  has-numbering" style="display: block; padding: 0px; background-color: transparent; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-top-left-radius: 0px; border-top-right-radius: 0px; border-bottom-right-radius: 0px; border-bottom-left-radius: 0px; word-wrap: normal; background-position: initial initial; background-repeat: initial initial;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">package</span> net.mobctrl.hostapk;

<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">import</span> java.io.File;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">import</span> java.io.FilenameFilter;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">import</span> java.util.ArrayList;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">import</span> java.util.List;

<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">import</span> android.annotation.TargetApi;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">import</span> android.content.Context;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">import</span> android.os.Build;

<span class="hljs-javadoc" style="color: rgb(136, 0, 0); box-sizing: border-box;">/**
 *<span class="hljs-javadoctag" style="color: rgb(102, 0, 102); box-sizing: border-box;"> @Author</span> Zheng Haibo
 *<span class="hljs-javadoctag" style="color: rgb(102, 0, 102); box-sizing: border-box;"> @PersonalWebsite</span> http://www.mobctrl.net
 *<span class="hljs-javadoctag" style="color: rgb(102, 0, 102); box-sizing: border-box;"> @version</span> $Id: BundleClassLoaderManager.java, v 0.1 2015年12月11日 下午7:30:59
 *          mochuan.zhb Exp $
 *<span class="hljs-javadoctag" style="color: rgb(102, 0, 102); box-sizing: border-box;"> @Description</span>
 */</span>
<span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@TargetApi</span>(Build.VERSION_CODES.ICE_CREAM_SANDWICH)
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-class" style="box-sizing: border-box;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">class</span> <span class="hljs-title" style="box-sizing: border-box; color: rgb(102, 0, 102);">BundleClassLoaderManager</span> {</span>

    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">static</span> List<BundleDexClassLoader> bundleDexClassLoaderList = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> ArrayList<BundleDexClassLoader>();

    <span class="hljs-javadoc" style="color: rgb(136, 0, 0); box-sizing: border-box;">/**
     * 載入Assets裡的apk檔案
     *<span class="hljs-javadoctag" style="color: rgb(102, 0, 102); box-sizing: border-box;"> @param</span> context
     */</span>
    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">static</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">install</span>(Context context) {
        AssetsManager.copyAllAssetsApk(context);
        <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 獲取dex檔案列表</span>
        File dexDir = context.getDir(AssetsManager.APK_DIR,
                Context.MODE_PRIVATE);
        File[] szFiles = dexDir.listFiles(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> FilenameFilter() {

            <span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">boolean</span> <span class="hljs-title" style="box-sizing: border-box;">accept</span>(File dir, String filename) {
                <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> filename.endsWith(AssetsManager.FILE_FILTER);
            }
        });
        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">for</span> (File f : szFiles) {
            System.out.println(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"debug:load file:"</span> + f.getName());
            BundleDexClassLoader bundleDexClassLoader = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> BundleDexClassLoader(
                    f.getAbsolutePath(), dexDir.getAbsolutePath(), <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span>,
                    context.getClassLoader());
            bundleDexClassLoaderList.add(bundleDexClassLoader);
        }
    }

    <span class="hljs-javadoc" style="color: rgb(136, 0, 0); box-sizing: border-box;">/**
     * 查詢類
     * 
     *<span class="hljs-javadoctag" style="color: rgb(102, 0, 102); box-sizing: border-box;"> @param</span> className
     *<span class="hljs-javadoctag" style="color: rgb(102, 0, 102); box-sizing: border-box;"> @return</span>
     *<span class="hljs-javadoctag" style="color: rgb(102, 0, 102); box-sizing: border-box;"> @throws</span> ClassNotFoundException
     */</span>
    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">static</span> Class<?> <span class="hljs-title" style="box-sizing: border-box;">loadClass</span>(Context context,String className) <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">throws</span> ClassNotFoundException {
        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">try</span> {
            Class<?> clazz = context.getClassLoader().loadClass(className);
            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (clazz != <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span>) {
                System.out.println(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"debug: class find in main classLoader"</span>);
                <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> clazz;
            }
        } <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">catch</span> (Exception e) {
            e.printStackTrace();
        }
        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">for</span> (BundleDexClassLoader bundleDexClassLoader : bundleDexClassLoaderList) {
            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">try</span> {
                Class<?> clazz = bundleDexClassLoader.loadClass(className);
                <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (clazz != <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span>) {
                    System.out.println(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"debug: class find in bundle classLoader"</span>);
                    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> clazz;
                }
            } <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">catch</span> (Exception e) {
                e.printStackTrace();
            }
        }
        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">throw</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> ClassCastException(className + <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">" not found exception"</span>);
    }
}
</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; background-color: rgb(238, 238, 238); top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right;"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li><li style="box-sizing: border-box; padding: 0px 5px;">33</li><li style="box-sizing: border-box; padding: 0px 5px;">34</li><li style="box-sizing: border-box; padding: 0px 5px;">35</li><li style="box-sizing: border-box; padding: 0px 5px;">36</li><li style="box-sizing: border-box; padding: 0px 5px;">37</li><li style="box-sizing: border-box; padding: 0px 5px;">38</li><li style="box-sizing: border-box; padding: 0px 5px;">39</li><li style="box-sizing: border-box; padding: 0px 5px;">40</li><li style="box-sizing: border-box; padding: 0px 5px;">41</li><li style="box-sizing: border-box; padding: 0px 5px;">42</li><li style="box-sizing: border-box; padding: 0px 5px;">43</li><li style="box-sizing: border-box; padding: 0px 5px;">44</li><li style="box-sizing: border-box; padding: 0px 5px;">45</li><li style="box-sizing: border-box; padding: 0px 5px;">46</li><li style="box-sizing: border-box; padding: 0px 5px;">47</li><li style="box-sizing: border-box; padding: 0px 5px;">48</li><li style="box-sizing: border-box; padding: 0px 5px;">49</li><li style="box-sizing: border-box; padding: 0px 5px;">50</li><li style="box-sizing: border-box; padding: 0px 5px;">51</li><li style="box-sizing: border-box; padding: 0px 5px;">52</li><li style="box-sizing: border-box; padding: 0px 5px;">53</li><li style="box-sizing: border-box; padding: 0px 5px;">54</li><li style="box-sizing: border-box; padding: 0px 5px;">55</li><li style="box-sizing: border-box; padding: 0px 5px;">56</li><li style="box-sizing: border-box; padding: 0px 5px;">57</li><li style="box-sizing: border-box; padding: 0px 5px;">58</li><li style="box-sizing: border-box; padding: 0px 5px;">59</li><li style="box-sizing: border-box; padding: 0px 5px;">60</li><li style="box-sizing: border-box; padding: 0px 5px;">61</li><li style="box-sizing: border-box; padding: 0px 5px;">62</li><li style="box-sizing: border-box; padding: 0px 5px;">63</li><li style="box-sizing: border-box; padding: 0px 5px;">64</li><li style="box-sizing: border-box; padding: 0px 5px;">65</li><li style="box-sizing: border-box; padding: 0px 5px;">66</li><li style="box-sizing: border-box; padding: 0px 5px;">67</li><li style="box-sizing: border-box; padding: 0px 5px;">68</li><li style="box-sizing: border-box; padding: 0px 5px;">69</li><li style="box-sizing: border-box; padding: 0px 5px;">70</li><li style="box-sizing: border-box; padding: 0px 5px;">71</li><li style="box-sizing: border-box; padding: 0px 5px;">72</li><li style="box-sizing: border-box; padding: 0px 5px;">73</li><li style="box-sizing: border-box; padding: 0px 5px;">74</li><li style="box-sizing: border-box; padding: 0px 5px;">75</li><li style="box-sizing: border-box; padding: 0px 5px;">76</li><li style="box-sizing: border-box; padding: 0px 5px;">77</li><li style="box-sizing: border-box; padding: 0px 5px;">78</li><li style="box-sizing: border-box; padding: 0px 5px;">79</li><li style="box-sizing: border-box; padding: 0px 5px;">80</li></ul>

注意點：

1.install方法
install方法主要是將assets中的apk全部拷貝到私有目錄，然後再遍歷私有目錄，使用BundleDexClassLoader載入apk檔案，然後將這些BundleDexClassLoader儲存到陣列中。
2.loadClass方法
該方法先從當前的ClassLoader中查詢需要的類，如果找不到，在從List中遍歷查詢。

DEMO執行

在MainActivity中，我們可以通過如下方式，呼叫apk類中的方法：

<code class="language-java hljs  has-numbering" style="display: block; padding: 0px; background-color: transparent; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-top-left-radius: 0px; border-top-right-radius: 0px; border-bottom-right-radius: 0px; border-bottom-left-radius: 0px; word-wrap: normal; background-position: initial initial; background-repeat: initial initial;">      <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">private</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">loadApk</span>() {
        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">try</span> {
            Class<?> clazz = BundleClassLoaderManager.loadClass(getApplicationContext(),
                    <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"net.mobctrl.normal.apk.Utils"</span>);
            Constructor<?> constructor = clazz.getConstructor();
            Object bundleUtils = constructor.newInstance();

            Method printSumMethod = clazz.getMethod(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"printSum"</span>, Context.class,
                    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span>.class, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span>.class, String.class);
            printSumMethod.setAccessible(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">true</span>);
            Integer sum = (Integer) printSumMethod.invoke(bundleUtils,
                    getApplicationContext(), <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">10</span>, <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">20</span>, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"計算結果"</span>);
            System.out.println(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"debug:sum = "</span> + sum);
        } <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">catch</span> (ClassNotFoundException e) {
            e.printStackTrace();
        } <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">catch</span> (SecurityException e) {
            e.printStackTrace();
        } <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">catch</span> (NoSuchMethodException e) {
            e.printStackTrace();
        } <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">catch</span> (IllegalArgumentException e) {
            e.printStackTrace();
        } <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">catch</span> (InstantiationException e) {
            e.printStackTrace();
        } <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">catch</span> (IllegalAccessException e) {
            e.printStackTrace();
        } <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">catch</span> (InvocationTargetException e) {
            e.printStackTrace();
        }
    }</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; background-color: rgb(238, 238, 238); top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right;"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li></ul>

與MultiDex不同時，我們是通過BundleClassLoaderManager來載入類的，而不是當前的ClassLoader。

改進方案

正如BundleClassLoaderManager中的loadClass方法，其實我們建立一個ClassLoader物件，通過重寫當前ClassLoader的findClass方法即可，然後在Override的findClass方法中，首先從當前ClassLoader中查詢類，然後再從BundleDexClassLoader中遍歷查詢，這樣既可以在Host專案中呼叫Bundle中的類，也能夠在Bundle中呼叫Host中的類。

<code class="language-java hljs  has-numbering" style="display: block; padding: 0px; background-color: transparent; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-top-left-radius: 0px; border-top-right-radius: 0px; border-bottom-right-radius: 0px; border-bottom-left-radius: 0px; word-wrap: normal; background-position: initial initial; background-repeat: initial initial;">
       mClassLoader = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> ClassLoader(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>.getClassLoader()) {

            <span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">protected</span> Class<?> <span class="hljs-title" style="box-sizing: border-box;">findClass</span>(String className)
                    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">throws</span> ClassNotFoundException {
                Class clazz = BundleClassLoaderManager.loadClass(context,className);
                <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (clazz == <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span>) {
                    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">throw</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> ClassNotFoundException(className);
                }
                <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> clazz;
            }
        };
</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; background-color: rgb(238, 238, 238); top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right;"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li></ul>

總結

上一篇部落格和這一篇部落格將的都是類的載入。如果所需要載入的類都是工具類，不需要載入資源等，那麼上面的方案都沒啥問題。但是如果載入的類是Fragment或者Activity等UI，需要引用資原始檔，這又改如何處理呢？

下一篇博文：Android資源的離線載入。

參考

1.BaseDexClassLoader原始碼

Android外掛化（一）：使用改進的MultiDex動態載入assets中的apk
2016-01-08
AndroidIDEAPK
Android外掛化（三）：載入外掛apk中的Resource資源
2016-01-08
AndroidAPK
外掛化知識梳理(7) 類的動態載入入門
2017-12-21
Android 外掛化動態升級
2016-01-07
Android
動態載入APK原理分享
2016-01-07
APK
外掛化知識梳理(8) 類的動態載入原始碼分析
2017-12-13
原始碼
APK動態載入框架（DL）解析
2015-08-17
APK框架
寫個js/css動態載入的JavaScript外掛
2017-01-19
JSCSSJavaScript
Android-動態載入外掛資源,皮膚包的實現原理
2021-09-09
Android
使用 Webapck 優化 VS Code 外掛載入效能
2018-12-31
Web優化
外掛化知識梳理(9) 資源的動態載入示例及原始碼分析
2017-12-21
原始碼
Spring Boot 如何熱載入 jar 實現動態外掛？
2022-07-12
Spring BootJAR
Spring Boot 如何熱載入jar實現動態外掛？
2021-10-18
Spring BootJAR
Activity的外掛化(二)
2017-12-13
framework外掛化技術-類載入
2018-09-02
Framework
Android外掛化技術之旅 1 開篇 - 實現啟動外掛與呼叫外掛中的Activity和Service
2018-12-20
Android
Android外掛化原理（一）Activity外掛化
2018-05-28
Android
熱修復與外掛化基礎——Java與Android的類載入器
2018-05-17
JavaAndroid
基於 webpack 的 SPA 單頁 Web 應用動態載入外掛的機制
2017-03-07
Web
Android動態載入jar/dex
2016-12-26
AndroidJAR
Flutter外掛開發之APK自動安裝
2019-06-13
FlutterAPK
外掛化設計二
2018-01-18
圖片載入外掛imagesLoaded的配置和使用
2016-10-29
動態庫so打包到android apk
2011-07-21
AndroidAPK
Android Studio Plugin 外掛開發教程（二） —— 外掛SDK中的常用物件介紹
2017-08-28
AndroidPlugin物件
使用dlopen載入動態庫
2021-02-28
Android外掛化的相容性（中）：Android P的適配
2018-08-23
Android
Pro Motion Blur Mac(動態模外掛fcpx外掛)
2022-06-14
Mac
位元組碼技術---------動態代理，lombok外掛底層原理。類載入器
2019-03-25
Lombok
android: 動態載入碎片佈局的技巧
2016-01-27
Android
外掛化之程式碼呼叫與載入資源
2018-11-08
Android外掛化開篇
2019-04-22
Android
淺析Android外掛化
2018-04-05
Android
Android 開發中如何動態載入 so 庫檔案
2017-03-31
Android
Android外掛化——VirtualAPK外掛框架接入專案
2018-02-08
AndroidAPK框架
web的自動化測試外掛Selenium-IDE外掛的安裝使用
2016-03-07
WebIDE
Android外掛化快速入門與例項解析（VirtualApk）
2019-03-04
AndroidAPK
Vue圖片懶載入之lazyload外掛使用
2018-06-11
Vue

Android外掛化（二）：使用DexClassLoader動態載入assets中的apk

轉自：http://blog.csdn.net/nupt123456789/article/details/50411581

簡介

原始碼

BundleClassLoaderManager

DEMO執行

改進方案

總結

參考

相關文章