Androidのメモリ情報を取得し文字列にする

getMemoryString

    @NonNull
    private String getMemoryString() {
        int memoryClass = ((ActivityManager) getSystemService(ACTIVITY_SERVICE)).getMemoryClass();
        int largeMemoryClass = ((ActivityManager) getSystemService(ACTIVITY_SERVICE)).getLargeMemoryClass();

        // メモリ情報を取得
        ActivityManager activityManager = (ActivityManager)getSystemService(ACTIVITY_SERVICE);
        ActivityManager.MemoryInfo memoryInfo = new ActivityManager.MemoryInfo();
        activityManager.getMemoryInfo(memoryInfo);

        int avaliMem = (int) (memoryInfo.availMem / 1024 / 1024);
        int threshold = (int) (memoryInfo.threshold / 1024 / 1024);
        boolean lowMemory = memoryInfo.lowMemory;


        int nativeAllocate = (int) (Debug.getNativeHeapAllocatedSize() / 1024 / 1024);
        int dalvikTotal = (int) (Runtime.getRuntime().totalMemory() / 1024 / 1024);
        int dalvikFree = (int) (Runtime.getRuntime().freeMemory() / 1024 / 1024);

        int javaAllocate = dalvikTotal - dalvikFree;

        int totalAllocate = nativeAllocate + javaAllocate;

        int ratio = (int)((double) totalAllocate / memoryClass * 100);
        int largeRatio = (int)((double) totalAllocate / largeMemoryClass * 100);


        return "使用可能メモリ = " + String.valueOf(memoryClass) + " MB\n"
                + "使用可能メモリ(large) = " + largeMemoryClass + " MB\n"
                + "native割当済み = " + nativeAllocate + " MB\n"
                + "java割当済み = " + javaAllocate + " MB\n"
                + "total割当済み = " + totalAllocate + " MB\n"
                + "使用率 = " + ratio + "%\n"
                + "使用率(large) = " + largeRatio + "%\n"
                + "(dalvik最大メモリ = " + dalvikTotal + " MB)\n"
                + "(dalvik空きメモリ = " + dalvikFree + " MB)\n"
                + "availMem = " + avaliMem + " MB\n"
                + "threshold = " + threshold + " MB\n"
                + "lowMemory = " + lowMemory;
    }