// 获得可用的内存
public class memInfo {
 
    public static long getmem_UNUSED(Context mContext) {
        long MEM_UNUSED;
// 得到ActivityManager
        ActivityManager am = (ActivityManager) mContext.getSystemService(Context.ACTIVITY_SERVICE);
// 创建ActivityManager.MemoryInfo对象  
        ActivityManager.MemoryInfo mi = new ActivityManager.MemoryInfo();
        am.getMemoryInfo(mi);
// 取得剩余的内存空间 
        MEM_UNUSED = mi.availMem / 1024;
        return MEM_UNUSED;
    }
    // 获得总内存
    public static long getmem_TOLAL() {
        long mTotal;
        // /proc/meminfo读出的内核信息进行解释
        String path = "/proc/meminfo";
        String content = null;
        BufferedReader br = null;
        try {
            br = new BufferedReader(new FileReader(path), 8);
            String line;
            if ((line = br.readLine()) != null) {
                content = line;
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (br != null) {
                try {
                    br.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        // beginIndex
        int begin = content.indexOf(':');
        // endIndex
        int end = content.indexOf('k');
        // 截取字符串信息
content = content.substring(begin + 1, end).trim();
        mTotal = Integer.parseInt(content);
        return mTotal;
    }
}