Android下如何擷取CPU序號

 public static String getCPUSerial() {  
        String str = "", strCPU = "", cpuAddress = "0000000000000000";   
        try {    
            //讀取CPU資訊    
            Process pp = Runtime.getRuntime().exec("cat /proc/cpuinfo");     
            InputStreamReader ir = new InputStreamReader(pp.getInputStream());   

            LineNumberReader input = new LineNumberReader(ir);   
            //尋找CPU序號  
            for (int i = 1; i < 100; i++) {  
                str = input.readLine();  
                if (str != null) {  
                    //尋找到序號所在行  
                    if (str.indexOf("Serial") > -1) {  
                        //提取序號  
                        strCPU = str.substring(str.indexOf(":") + 1,  
                        str.length());  
                        //去空格  
                        cpuAddress = strCPU.trim();  
                        break;  
                    }  
                } else {  
                    //檔案結尾  
                    break;  
                }  
            }  
        } catch (Exception ex) {  
            //賦予預設值  
            ex.printStackTrace();  
        }  
        return cpuAddress;  
   } 

註：有的系統下不能擷取CPU序號，結果都是"0000000000000000"