XStream pom依赖：
<dependency> <groupId>com.thoughtworks.xstream</groupId> <artifactId>xstream</artifactId> <version>1.4.10</version> </dependency>
1、对象解析成xml字符串时下划线变成双下划线
解决：
xStream = new XStream(new DomDriver("UTF-8", new XmlFriendlyNameCoder("_-", "_")));
或者
xStream = new XStream(new Xpp3Driver(new NoNameCoder()));
2、Security framework of XStream not initialized, XStream is probably vulnerable
解决：
XStream.setupDefaultSecurity(xStream); xStream.allowTypesByWildcard(new String[] { "com.common.util.**" //你的包路径 });
3、处理既有属性又有值的情况
形如：<Query Code="1">select * from user</Query>
使用自定义转换器实现,如下：
public class QueryConverter implements Converter { @Override public boolean canConvert(Class type) { return type.equals(Query.class); } /** * 将java对象转为xml时使用 */ @Override public void marshal(Object source, HierarchicalStreamWriter writer, MarshallingContext context) { Query query = (Query) source; // 设置属性值 writer.addAttribute("Code", query.getCode()); // 设置文本值 writer.setValue(query.getText()); } /** * 将xml转为java对象使用 */ @Override public Object unmarshal(HierarchicalStreamReader reader, UnmarshallingContext context) { Query query = new Query(); query.setTransactionCode(reader.getAttribute("Code")); query.setText(reader.getValue()); return query; } }
之后通过注解@XStreamConverter(value = QueryConverter.class)
或代码注册转换器使用：
xStream.registerConverter(new xxxConverter());
4、时间转换器
字段为Date类型
public class DateConverter implements Converter { @Override public boolean canConvert(Class arg0) { return Date.class == arg0; } @Override public void marshal(Object arg0, HierarchicalStreamWriter arg1, MarshallingContext arg2) { } @Override public Object unmarshal(HierarchicalStreamReader reader, UnmarshallingContext arg1) { GregorianCalendar calendar = new GregorianCalendar(); //格式化当前系统日期 SimpleDateFormat dateFm = new SimpleDateFormat("yyyy-MM-dd"); try { calendar.setTime(dateFm.parse(reader.getValue())); } catch (ParseException e) { throw new ConversionException(e.getMessage(), e); } return calendar.getTime(); } }
使用：
@XStreamConverter(DateConverter.class) private Date beginTime;
属性为Date类型处理SingleValueConverter
public class XStreamDateConverter implements SingleValueConverter { @Override public boolean canConvert(Class arg0) { return Date.class == arg0; } @Override public Object fromString(String arg0) { SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd"); try { return format.parse(arg0); } catch (ParseException e) { e.printStackTrace(); } return null; } @Override public String toString(Object arg0) { SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd"); try { return format.format((Date) arg0); } catch (Exception e) { e.printStackTrace(); } return ""; } }
之后将转化加在Date属性的字段上使用即可
@XStreamConverter(value=XStreamDateConverter.class) @XStreamAsAttribute private Date beginTime;
5、针对null值的字段也显示在xml中处理
大概思路就是遍历对象的所有的字段，若当前字段的值为null，则处理成空字符串，示例自定义转换器如下：
public class FieldConverter implements Converter { /** * 日志记录 */ private static final Logger LOGGER = LoggerFactory.getLogger(FieldConverter.class); /** * 时间格式 */ private String formatPattern; public FieldConverter() { } public FieldConverter(String formatPattern) { this.formatPattern = formatPattern; } @Override public boolean canConvert(Class type) { return true; } /** * 将java对象转为xml时使用 */ @Override public void marshal(Object source, HierarchicalStreamWriter writer, MarshallingContext context) { try { handleSource(source, writer); } catch (Exception e) { LOGGER.error("[FieldConverter] marshal 异常，{}", e); throw new IllegalArgumentException("转换xml出错"); } } /** * @description ：处理对象为xml转换 * @param source 对象源 * @param writer 流写出对象 * @date 2019/9/29 18:48 * @modifier * @return void */ private void handleSource(Object source, HierarchicalStreamWriter writer) throws IllegalAccessException { try { Class<?> aClass = source.getClass(); Field[] declaredFields = aClass.getDeclaredFields(); for (Field currField : declaredFields) { currField.setAccessible(Boolean.TRUE); // 字段注解 boolean isAttr = currField.isAnnotationPresent(XStreamAsAttribute.class); boolean isXStreamAlias = currField.isAnnotationPresent(XStreamAlias.class); boolean isFieldValue = currField.isAnnotationPresent(FieldValue.class); // 当前字段值 Object curFieldValue = currField.get(source); // 字段别名 String xmlAlias; if (isXStreamAlias) { xmlAlias = currField.getAnnotation(XStreamAlias.class).value(); } else { xmlAlias = currField.getName(); } if (isAttr) { // 字段属性 writer.addAttribute(xmlAlias, null == curFieldValue ? "" : String.valueOf(curFieldValue)); } else if (isFieldValue) { // 字段值 writer.setValue(String.valueOf(curFieldValue)); } else { // 字段简单处理 boolean isBaseType = DomainUtil.isBaseType(currField.getType()); if (curFieldValue instanceof List) { List<Object> list = (List<Object>) curFieldValue; for (int i = 0; i < list.size(); i++) { writer.startNode(xmlAlias + i); Object curr = list.get(i); isBaseType = DomainUtil.isBaseType(curr.getClass()); if (null == curr || isBaseType) { writer.setValue(null == curr ? "" : String.valueOf(curr)); } else { handleSource(curr, writer); } writer.endNode(); } } else { // 开始节点 writer.startNode(xmlAlias); if (null == curFieldValue || isBaseType) { writer.setValue(null == curFieldValue ? "" : String.valueOf(curFieldValue)); } else if (currField.getType().equals(Date.class)) { //时间对象 SimpleDateFormat format = new SimpleDateFormat(formatPattern); writer.setValue(null == curFieldValue ? "" : format.format(curFieldValue)); } else { //对象类型 handleSource(curFieldValue, writer); } // 结束节点 writer.endNode(); } } } } catch (Exception e) { LOGGER.error("[FieldConverter] handleSource 异常，{}", e); throw e; } } /** * 将xml转为java对象使用 */ @Override public Object unmarshal(HierarchicalStreamReader reader, UnmarshallingContext context) { System.out.println("coming....."); return null; }