UiAutomator2.0 脱离PC运行报：android ADB server didn't ACK * failed to start daemon

[luduntao]

代码如下：
class UiautomatorThread extends Thread {
@Override
public void run() {
super.run();
String command=generateCommand("com.example.ldt.test", "Runner", "testDemo");
CMDUtils.CMD_Result rs= CMDUtils.runCMD(command,true,true);
Log.e(TAG, "run: " + rs.error + "-------" + rs.success);
}

/**
* 生成命令
* @param pkgName 包名
* @param clsName 类名
* @param mtdName 方法名
* @return
*/
public String generateCommand(String pkgName, String clsName, String mtdName) {
String command = "adb shell am instrument --user 0 -w -r -e debug false -e class "
+ pkgName + "." + clsName + "#" + mtdName + " "
+ pkgName + ".test/android.support.test.runner.AndroidJUnitRunner";
Log.e("test1: ", command);
return command;
}

报错如下：
I/MainActivity: runMyUiautomator
E/test1:: adb shell am instrument --user 0 -w -r -e debug false -e class com.example.ldt.test.Runner#testDemo com.example.ldt.test.test/android.support.test.runner.AndroidJUnitRunner
I/CMDUtils: runCMD:adb shell am instrument --user 0 -w -r -e debug false -e class com.example.luduntao.test.Runner#testDemo com.example.luduntao.test.test/android.support.test.runner.AndroidJUnitRunner
E/MainActivity: run: ADB server didn't ACK* failed to start daemon *error: cannot connect to daemon-------cannot bind 'tcp:5038'* daemon not running. starting it now on port 5038 *