java - 流异常 : An invalid XML character (Unicode: 0x1a)

Question

我正在使用 XStream 将用户对象保存在文件中。

private void store() {
    XStream xStream = new XStream(new DomDriver("UTF-8"));
    xStream.setMode(XStream.XPATH_ABSOLUTE_REFERENCES);

    xStream.alias("configuration", Configuration.class);
    xStream.alias("user", User.class);

    synchronized (ConfigurationDAOImpl.class) {
        try {
            xStream.toXML(configuration, new FileOutputStream(filename.getFile()));
        } catch (IOException e) {
            throw new RuntimeException("Failed to write to " + filename, e);
        }
    }
}

当我尝试通过以下代码读取它时，出现异常:com.thoughtworks.xstream.io.StreamException::在文档的元素内容中发现无效的 XML 字符(Unicode:0x1a)。

private void lazyLoad() {
    synchronized (ConfigurationDAOImpl.class) {
        // Has the configuration been loaded
        if (configuration == null) {
            if (filename.exists()) {
                try {
                    XStream xStream = new XStream(new DomDriver("UTF-8"));
                    xStream.setMode(XStream.XPATH_ABSOLUTE_REFERENCES);

                    xStream.alias("configuration", Configuration.class);
                    xStream.alias("user", User.class);

                    configuration = (Configuration) xStream
                            .fromXML(filename.getInputStream());

                    LOGGER.debug("Loaded configuration from {}.", filename);
                } catch (Exception e) {
                    LOGGER.error("Failed to load configuration.", e);
                }
            } else {
                LOGGER.debug("{} does not exist.", filename);
                LOGGER.debug("Creating blank configuration.");

                configuration = new Configuration();
                configuration.setUsers(new ArrayList<User>());

                // and store it
                store();
            }
        }
    }
}

有什么想法吗？

Answer 1

0x1a 是无效的 xml 字符。无法在 xml 1.0 文档中表示它。

引自http://en.wikipedia.org/wiki/XML#Valid_characters

Unicode code points in the following ranges are valid in XML 1.0 documents:[9] U+0009, U+000A, U+000D: these are the only C0 controls accepted in XML 1.0; U+0020–U+D7FF, U+E000–U+FFFD: this excludes some (not all) non-characters in the BMP (all surrogates, U+FFFE and U+FFFF are forbidden); U+10000–U+10FFFF: this includes all code points in supplementary planes, including non-characters.