最近在研究安卓的OTA rom，找到一个开源的项目https://github.com/MatthewBooth/OTAUpdates 其中用到了bypass。
bypass：Skip the HTML, Bypass takes markdown and renders it directly on Android and iOS.

使用Android Studio 1.3.2导入项目编译时出错：Error:(3, 31) 错误: 程序包in.uncod.android.bypass不存在。
这个包在src_bypass目录下，AS并没有导入这个目录。bypass需要用到NDK来编译。项目的Building说明是针对linux下Eclipse的，我用的是Window下AS，刚学Android，不知道怎么配置。
偷懒找到一个使用的AS的bypass项目：https://github.com/actorapp/bypass 导入项目后，出现以下问题：

1.未设置NDK的路径

Error:Execution failed for task ':library:ndkBuild'. > A problem occurred starting process 'command 'null/ndk-build''
配置NDK的的安装路径即可。
1）设置环境变量：新增ANDROID_NDK_HOME键值为Android NDK安装目录，在PATH末尾增加;%ANDROID_NDK_HOME%。

或者2）在AS的project structure设置，如下图：

2. 调用的ndk-build命令不对

Error:Execution failed for task ':library:ndkBuild'.> A problem occurred starting process 'command 'D:\androidDev\android-ndk-r10e/ndk-build''

在stackoverflow上找到原因，build.gradle文件中

taskndkBuild(type: Exec,description:'Compile JNI source via NDK') {
    defndkDir =project.plugins.findPlugin('com.android.library').sdkHandler.ndkFolder
    workingDir"$projectDir/src/main/jni"
    commandLine"$ndkDir/ndk-build"
}

commandLine"$ndkDir/ndk-build"这一行windows下应该用ndk-build.cmd

3. 找不到boost库文件

项目Readme中有说明

Manual Build
Make sureBYPASS_INCLUDE_PATH to its parent directory.

设置环境变量：新增BYPASS_INCLUDE_PATH键值为boost的安装目录，在PATH末尾增加;%BYPASS_INCLUDE_PATH%。

折腾好久，终于编译通过！

Log开关的使用

代码中有一段Benchmark耗时的打印输出

public class BenchmarkActivity extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.main);

    TextView text = (TextView) findViewById(R.id.demoText);

    TimingLogger timings = new TimingLogger("Bypass", "onCreate");

    String readme = loadFile();

    timings.addSplit("read raw");

    Bypass bypass = new Bypass(BenchmarkActivity.this);

    timings.addSplit("instantiated Bypass");

    CharSequence string = bypass.markdownToSpannable(readme);

    timings.addSplit("convert to spannable");
    timings.dumpToLog();

    text.setText(string);
    //Allows link clicking
    text.setMovementMethod(LinkMovementMethod.getInstance());
    }
    ......
}

logcat中却看不到。调试跟踪发现这个打印是通过Log.isLoggable来控制开关。在adb shell中设置属性setprop log.tag.Bypass VERBOSE打开打印输出或者写在local.properties中，就可以看到打印输出了。

09-07 09:24:12.111 25845-25845/in.uncod.android.bypass.test D/Bypass﹕ onCreate: begin
09-07 09:24:12.111 25845-25845/in.uncod.android.bypass.test D/Bypass﹕ onCreate: 1 ms, read raw
09-07 09:24:12.111 25845-25845/in.uncod.android.bypass.test D/Bypass﹕ onCreate: 29 ms, instantiated Bypass
09-07 09:24:12.111 25845-25845/in.uncod.android.bypass.test D/Bypass﹕ onCreate: 11 ms, convert to spannable
09-07 09:24:12.111 25845-25845/in.uncod.android.bypass.test D/Bypass﹕ onCreate: end, 41 ms