匯出首選項

Preferences 節點可以匯出到表示該節點的 XML 文件中。生成的 XML 樹可以再次匯入。生成的 XML 文件將記住它是從使用者還是系統 Preferences 匯出。

要匯出單個節點，但不匯出其子節點 ：

Version >= Java SE 7

try (OutputStream os = ...) {
    preferences.exportNode(os);
} catch (IOException ioe) {
    // Exception whilst writing data to the OutputStream
    ioe.printStackTrace();
} catch (BackingStoreException bse) {
    // Exception whilst reading from the backing preferences store
    bse.printStackTrace();
}

Version < Java SE 7

OutputStream os = null;
try {
    os = ...;
    preferences.exportSubtree(os);
} catch (IOException ioe) {
    // Exception whilst writing data to the OutputStream
    ioe.printStackTrace();
} catch (BackingStoreException bse) {
    // Exception whilst reading from the backing preferences store
    bse.printStackTrace();
} finally {
    if (os != null) {
        try {
            os.close();
        } catch (IOException ignored) {}
    }
}

要使用其子節點匯出單個節點 ：

Version >= Java SE 7

try (OutputStream os = ...) {
    preferences.exportNode(os);
} catch (IOException ioe) {
    // Exception whilst writing data to the OutputStream
    ioe.printStackTrace();
} catch (BackingStoreException bse) {
    // Exception whilst reading from the backing preferences store
    bse.printStackTrace();
}

Version < Java SE 7

OutputStream os = null;
try {
    os = ...;
    preferences.exportSubtree(os);
} catch (IOException ioe) {
    // Exception whilst writing data to the OutputStream
    ioe.printStackTrace();
} catch (BackingStoreException bse) {
    // Exception whilst reading from the backing preferences store
    bse.printStackTrace();
} finally {
    if (os != null) {
        try {
            os.close();
        } catch (IOException ignored) {}
    }
}