xml文本格式是网络通信中最常用的格式，最近特别研究了一下如何解析xml文本并转换为对象，现在分享一下我最近的学习成果~
先列一下本例中需要解析的xml文本：
讲一下我的思路，我选择使用XStream来解析xml文本，因为xstream在转换对象方面会比dom4j更优秀一些，它是通过注解方式来声明对应结点的，在操作上会更直观方便。首先会将整个文本转换成一个Results类对象，而每一个row结点作为一个HashMap放入到Results类对象的List列表中，最后会将每一个HashMap读取出来通过JAVA的反射机制转换为Info对象，并生成List列表。
public class Info {private String id;
private String title;
private String content;
private String author;
private String pubtime;
public String getId {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getTitle {
return title;
}
public void setTitle(String title) {
this.title = title;
}
public String getContent {
return content;
}
public void setContent(String content) {
this.content = content;
}
public String getAuthor {
return author;
}
public void setAuthor(String author) {
this.author = author;
}
public String getPubtime {
return pubtime;
}
public void setPubtime(String pubtime) {
this.pubtime = pubtime;
}
@Override
public String toString {
return "Info [author=" + author + ", content=" + content + ", id=" + id
+ ", pubtime=" + pubtime + ", title=" + title + "]";
}} @XStreamConverter(RowConverter.class)
public class Row extends HashMap<String, String> {private static final long serialVersionUID = 5619951409573339302L;
} @XStreamAlias("results")
public class Results {
@XStreamAlias("name")@XStreamAsAttributeprivate String name;@XStreamImplicit(itemFieldName = "row")private List<Row> rows;public String getName {return name;}public void setName(String name) {this.name = name;}public List<Row> getRows {
return rows;
}public void setRows(List<Row> rows) {
this.rows = rows;
}} public class RowConverter extends AbstractCollectionConverter {public RowConverter(Mapper mapper) {
super(mapper);
// TODO Auto-generated constructor stub
}@Override
public boolean canConvert(Class arg0) {
// TODO Auto-generated method stub
return Row.class.equals(arg0);
}@Override
public void marshal(Object arg0, HierarchicalStreamWriter writer,
MarshallingContext arg2) {
// TODO Auto-generated method stub
Row map = (Row) arg0;for (Iterator iterator = map.entrySet.iterator; iterator.hasNext;) {Map.Entry entry = (Map.Entry) iterator.next;writer.addAttribute(entry.getKey.toString, entry.getValue.toString);}
}@Override
public Object unmarshal(HierarchicalStreamReader reader,
UnmarshallingContext context) {
// TODO Auto-generated method stubRow map = new Row;populateMap(reader, context, map);return map;
}protected void populateMap(HierarchicalStreamReader reader, UnmarshallingContext context, Row map) {Iterator<String> iterator = reader.getAttributeNames;while (iterator.hasNext) {Object key = iterator.next;String value = reader.getAttribute((String) key);map.put(key.toString, value.toString);}}
}
RowConverter是一个转换器类，作用是将每一个row结点转变一个HashMap。
测试类：
publicclass Xstream {private static String xml;public static void main(String[] args) throws Exception{
//初始化
init;XStream xstream = new XStream(new XppDriver(new
XmlFriendlyReplacer("_-", "_")));
//解析xml文本
xstream.processAnnotations(Results.class);
Results results = (Results) xstream.fromXML(xml);
//将解析出来的Results类对象转化成list列表
List<Info> list = createList(Info.class,results);for(int i=0;i<list.size;i++){
//打印
Info info = list.get(i);
System.out.println(info.toString);
}}
public static void init{
//初始化xml文本
xml ="<results name=\"list\"><row pubtime=\"2016-04-13
16:40:13\" author=\"APP\" id=\"140\" title=\"什么是公告\"
content=\"公告，是公开宣告。\" /><row pubtime=\"2016-04-13 16:36:50\"
author=\"网站\" id=\"138\" title=\"12345678\" content=\"12345678\"
/><row pubtime=\"2016-04-06 15:02:44\" author=\"网站\" id=\"134\"
title=\"关于网站用户注册流程说明1\" content=\"关于用户注册流程说明\" /><row
pubtime=\"2016-03-30 18:32:13\" author=\"APP\" id=\"126\"
title=\"关于网站使用说明\" content=\"测试\" /><row pubtime=\"2016-03-30
18:29:26\" author=\"网站\" id=\"125\" title=\"关于手机App使用说明\"
content=\"123\" /></results>";
}
public static <T> List createList(Class<T> clz ,Results
results) throws Exception{
List list = new ArrayList;
for(Row row :results.getRows){
//根据class和Row生成对象放入list
list.add(createObject(clz,row));}
return list;
}
public static <T> T createObject(Class<T> clazz ,Row row)
throws Exception{
//初始化对象
T obj = clazz.newInstance;
//遍历Info类中所有方法
for (Method method : clazz.getDeclaredMethods) {
String methodName = method.getName;
Class perams = method.getParameterTypes;
//找到set开头，长度大于3，并且入参数量为1的方法
if (methodName.startsWith("set") && methodName.length > 3
&& perams.length == 1) {String temp = methodName.substring(3, methodName.length);
//拿到属性名称
String fieldName = temp.toLowerCase;
//根据属性名称从HashMap中拿到对应的值
String value = row.get(fieldName);if(value != null){
//拿到该方法入参的Class，根据入参类型来决定调用方法形式
Class paramClass = perams[0];
if (String.class.equals(paramClass)) {
method.invoke(obj, value);
} else if (Integer.class.equals(paramClass) ||
int.class.equals(paramClass)) {
method.invoke(obj, Integer.valueOf(value));
} else if (Long.class.equals(paramClass) ||
long.class.equals(paramClass)) {
method.invoke(obj, Long.valueOf(value));
} else if (BigDecimal.class.equals(paramClass)) {
method.invoke(obj, new BigDecimal(value));
} else if (Boolean.class.equals(paramClass) ||
boolean.class.equals(paramClass)) {
if(value.equals("true")||value.equals("TRUE"))
method.invoke(obj, true);
if(value.equals("false")||value.equals("FALSE"))
method.invoke(obj, false);
}
}}
}
return obj;
}
}
最后是输出效果：
Info [author=APP, content=公告，是公开宣告。, id=140, pubtime=2016-04-13 16:40:13, title=什么是公告] Info [author=网站, content=12345678, id=138, pubtime=2016-04-13 16:36:50, title=12345678] Info [author=网站, content=关于用户注册流程说明, id=134, pubtime=2016-04-06 15:02:44, title=关于网站用户注册流程说明1] Info [author=APP, content=测试, id=126, pubtime=2016-03-30 18:32:13, title=关于网站使用说明] Info [author=网站, content=123, id=125, pubtime=2016-03-30 18:29:26, title=关于手机App使用说明]
