android內存管理工具類

    public class MemoryManager {

        private static final String TAG = "MemoryManager";

        private static final int MAXMEMORY=5010241024;//程序運行的最大內存

        /**


     * 判斷系統是否在低內存下運行 
     * @param context 
     * @return 
     */  
    public static boolean hasAcailMemory() {  
        // 獲取手機內部空間大小  
        long memory = getAvailableInternalMemorySize();  
        Log.i(TAG, memory+"");  
        if (memory < MAXMEMORY) {  
            //應用將處于低內存狀態下運行  
            return false;  
        } else {  
            return true;  
        }  
    }  

    /** 
     * 獲取手機內部可用空間大小 
     *  
     * @return 
     */  
    public static long getAvailableInternalMemorySize() {  
        File path = Environment.getDataDirectory();// 獲取 Android 數據目錄  
        StatFs stat = new StatFs(path.getPath());// 一個模擬linux的df命令的一個類,獲得SD卡和手機內存的使用情況  
        long blockSize = stat.getBlockSize();// 返回 Int ，大小，以字節為單位，一個文件系統  
        long availableBlocks = stat.getAvailableBlocks();// 返回 Int ，獲取當前可用的存儲空間  
        return availableBlocks * blockSize;  
    }  

    /** 
     * 獲取手機內部空間大小 
     *  
     * @return 
     */  
    public static long getTotalInternalMemorySize() {  
        File path = Environment.getDataDirectory();  
        StatFs stat = new StatFs(path.getPath());  
        long blockSize = stat.getBlockSize();  
        long totalBlocks = stat.getBlockCount();// 獲取該區域可用的文件系統數  
        return totalBlocks * blockSize;  
    }  

    /** 
     * 獲取手機外部可用空間大小 
     *  
     * @return 
     */  
    public static long getAvailableExternalMemorySize() {  
        if (externalMemoryAvailable()) {  
            File path = Environment.getExternalStorageDirectory();  
            StatFs stat = new StatFs(path.getPath());  
            long blockSize = stat.getBlockSize();  
            long availableBlocks = stat.getAvailableBlocks();  
            return availableBlocks * blockSize;  
        } else {  
            throw new RuntimeException("Don't have sdcard.");  
        }  
    }  

    /** 
     * 獲取手機外部空間大小 
     *  
     * @return 
     */  
    public static long getTotalExternalMemorySize() {  
        if (externalMemoryAvailable()) {  
            File path = Environment.getExternalStorageDirectory();// 獲取外部存儲目錄即 SDCard  
            StatFs stat = new StatFs(path.getPath());  
            long blockSize = stat.getBlockSize();  
            long totalBlocks = stat.getBlockCount();  
            return totalBlocks * blockSize;  
        } else {  
            throw new RuntimeException("Don't have sdcard.");  
        }  
    }  

    /** 
     * 外部存儲是否可用 
     *  
     * @return 
     */  
    public static boolean externalMemoryAvailable() {  
        return android.os.Environment.getExternalStorageState().equals(android.os.Environment.MEDIA_MOUNTED);  
    }  
}  </pre>