A way to get the CPU temperature from an android device by using the sys/class/thermal/temp command

GetCpuTempAndroid.java

public float getCpuTemp() {
        Process p;
        try {
            p = Runtime.getRuntime().exec("cat sys/class/thermal/thermal_zone0/temp");
            p.waitFor();
            BufferedReader reader = new BufferedReader(new InputStreamReader(p.getInputStream()));

            String line = reader.readLine();
            float temp = Float.parseFloat(line) / 1000.0f;

            return temp;

        } catch (Exception e) {
            e.printStackTrace();
            return 0.0f;
        }
}

On modern devices selinux is going to prevent you from accessing this node. Also, how the thermal zones map to actual hardware components depends on the CPU. On one device this might be the CPU diode but on another it could be the battery (or invalid).