Runtime ex = Runtime.getRuntime();

String cmdBecomeSu = "su";

String script = "busybox chmod a+rw /dev/pmem";

try

{

java.lang.Process runsum = ex.exec(cmdBecomeSu);

int exitVal = 0;

final OutputStreamWriter out = new OutputStreamWriter(runsum.getOutputStream());

// Write the script to be executed

out.write(script);

// Ensure that the last character is an "enter"

out.write("\n");

out.flush();

// Terminate the "su" process

out.write("exit\n");

out.flush();

exitVal = runsum.waitFor();

if (exitVal == 0)

{

Log.e("Debug", "Successfully to su");

}

}

catch ( Exception e)

{

Log.e("Debug", "Fails to su");

}

这段代码演示了如何在Java代码里，通过调用su命令来临时修改某些文件的访问权限

如果是测试程序，必须要root或者system权限可以用

android.permission.FACTORY_TEST 作为一个工厂测试程序，运行在root用户(Run as a manufacturer testapplication, running as the root user. )

摘自:

http://wyoojune.blog.163.com/blog/static/5709332520111011104026490/