/*** 得到系统内存信息的工具类* @author zwenkai*/
public class SystemInfoUtils {
    /**
* 得到运行的进程总个数
*
* @param context
* @return 运行进程个数
*/
public static int getRunningProcessCount(Context context) {
ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
	return am.getRunningAppProcesses().size();
}
    /**
* 得到可用内存数
*
* @param context
* @return
*/
public static long getAvailRam(Context context) {
ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
	MemoryInfo outInfo = new MemoryInfo();
am.getMemoryInfo(outInfo);
	return outInfo.availMem;
}
    /**
* 得到总内存数
*
* @param context
* @return
*/
public static long getTotalRam(Context context) {
	try {
File file = new File("/proc/meminfo");
BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream(file)));
String line = br.readLine();
br.close();
	    StringBuffer sb = new StringBuffer();
	    //MemTotal:         513000 kB
for (char c :line.toCharArray()) {
	        if(c > ‘0‘ && c < ‘9‘) {
sb.append(c);
}
}
	    return Integer.parseInt(sb.toString())*1024l;
	} catch (IOException e) {
e.printStackTrace();
	    return 0;
}
}
    //4.0之后可以使用
public long getTotalRam1(Context context) {
ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
	MemoryInfo outInfo = new MemoryInfo();
am.getMemoryInfo(outInfo);
	return outInfo.totalMem;
}
}
原文:http://www.cnblogs.com/loveandroid/p/3805125.html