求助:修改android framework源码时的出错问题

想在android源码的framework上添加一个toast,结果编译时候出错,提示找不到symbol,不知道问题出在哪里,请教大家,谢谢.添加的代码如下:
Toast toast = Toast.makeText(getApplicationContext(),"test",Toast.LENGTH_SHORT);
toast.show();
编译时的出错信息如下:
----- Made recovery image -------- out/target/product/recovery.img
target Java: services (out/target/common/obj/JAVA_LIBRARIES/services_intermediates/classes)
frameworks/base/services/java/com/android/server/ThermalManagerService.java:64: cannot find symbol
symbol  : method makeText(<anonymous java.lang.Runnable>,java.lang.String,int)
location: class android.widget.Toast
            Toast toast = Toast.makeText(this, "my test", Toast.LENGTH_SHORT);
                               ^
Note: Some input files use or override a deprecated API.
Note: Recompile with -Xlint:deprecation for details.
Note: Some input files use unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.
1 error
make: *** [out/target/common/obj/JAVA_LIBRARIES/services_intermediates/classes-full-debug.jar] Error 41