java - 用于 java web-app 的数据库支持的 i18n

Question

我想使用数据库来存储 i18n 键/值对，以便我们可以在运行时修改/重新加载 i18n 数据。有没有人这样做过？或者有人知道如何实现这个吗？我已经阅读了几个关于此的主题，但我还没有看到可行的解决方案。

我特别指的是一些可以与 jSTL 标签一起工作的东西，比如

<fmt:setlocale>
<fmt:bundle>
<fmt:setBundle>
<fmt:message>

我认为这将涉及扩展 ResourceBundle，但是当我尝试这样做时，我遇到了与 jSTL 标签获取资源包的方式有关的问题。

Answer 1

在 danb 的帮助下，我终于搞定了。

这是我的资源包类和资源包控制类。

我使用了@[danb] 的这段代码。

ResourceBundle bundle = ResourceBundle.getBundle("AwesomeBundle", locale, DbResourceBundle.getMyControl());
javax.servlet.jsp.jstl.core.Config.set(actionBeanContext.getRequest(), Config.FMT_LOCALIZATION_CONTEXT, new LocalizationContext(bundle, locale));

并编写了这个类。

public class DbResourceBundle extends ResourceBundle
{
    private Properties properties;

    public DbResourceBundle(Properties inProperties)
    {
        properties = inProperties;
    }

    @Override
    @SuppressWarnings(value = { "unchecked" })
    public Enumeration<String> getKeys()
    {
        return properties != null ? ((Enumeration<String>) properties.propertyNames()) : null;
    }

    @Override
    protected Object handleGetObject(String key)
    {
        return properties.getProperty(key);
    }

    public static ResourceBundle.Control getMyControl()
    {
        return new ResourceBundle.Control()
        {

            @Override
            public List<String> getFormats(String baseName)
            {
                if (baseName == null)
                {
                    throw new NullPointerException();
                }
                return Arrays.asList("db");
            }

            @Override
            public ResourceBundle newBundle(String baseName, Locale locale, String format, ClassLoader loader, boolean reload) throws IllegalAccessException,
                  InstantiationException, IOException
            {
                if ((baseName == null) || (locale == null) || (format == null) || (loader == null))
                    throw new NullPointerException();
                ResourceBundle bundle = null;
                if (format.equals("db"))
                {
                    Properties p = new Properties();
                    DataSource ds = (DataSource) ContextFactory.getApplicationContext().getBean("clinicalDataSource");
                    Connection con = null;
                    Statement s = null;
                    ResultSet rs = null;
                    try
                    {
                        con = ds.getConnection();
                        StringBuilder query = new StringBuilder();
                        query.append("select label, value from i18n where bundle='" + StringEscapeUtils.escapeSql(baseName) + "' ");

                        if (locale != null)
                        {
                            if (StringUtils.isNotBlank(locale.getCountry()))
                            {
                                query.append("and country='" + escapeSql(locale.getCountry()) + "' ");

                            }
                            if (StringUtils.isNotBlank(locale.getLanguage()))
                            {
                                query.append("and language='" + escapeSql(locale.getLanguage()) + "' ");

                            }
                            if (StringUtils.isNotBlank(locale.getVariant()))
                            {
                                query.append("and variant='" + escapeSql(locale.getVariant()) + "' ");

                            }
                        }
                        s = con.createStatement();
                        rs = s.executeQuery(query.toString());
                        while (rs.next())
                        {
                            p.setProperty(rs.getString(1), rs.getString(2));
                        }
                    }
                    catch (Exception e)
                    {
                        e.printStackTrace();
                        throw new RuntimeException("Can not build properties: " + e);
                    }
                    finally
                    {
                        DbUtils.closeQuietly(con, s, rs);
                    }
                    bundle = new DbResourceBundle(p);
                }
                return bundle;
            }

            @Override
            public long getTimeToLive(String baseName, Locale locale)
            {
                return 1000 * 60 * 30;
            }

            @Override
            public boolean needsReload(String baseName, Locale locale, String format, ClassLoader loader, ResourceBundle bundle, long loadTime)
            {
                return true;
            }

        };
    }