我正在使用 SimpleXML 库。我需要获取 rss feed 并将其转换为 java 对象。这里是我需要映射到对象的 XML
<rss xmlns:lj="http://www.livejournal.org/rss/lj/1.0/" xmlns:media="http://search.yahoo.com/mrss/" xmlns:atom10="http://www.w3.org/2005/Atom" version="2.0">
<channel>
<title>Всегда! Везде! Со всеми! и ни с кем!</title>
<link>http://xuma.livejournal.com/</link>
<description>
Всегда! Везде! Со всеми! и ни с кем! - LiveJournal.com
</description>
<lastBuildDate>Thu, 17 Mar 2011 10:08:33 GMT</lastBuildDate>
<generator>LiveJournal / LiveJournal.com</generator>
<lj:journal>xuma</lj:journal>
<lj:journalid>5295048</lj:journalid>
<lj:journaltype>personal</lj:journaltype>
<copyright>NOINDEX</copyright>
<image>
<url>http://l-userpic.livejournal.com/104864030/5295048</url>
<title>Всегда! Везде! Со всеми! и ни с кем!</title>
<link>http://xuma.livejournal.com/</link>
<width>66</width>
<height>100</height>
</image>
<item>
<guid isPermaLink="true">http://xuma.livejournal.com/7831.html</guid>
<pubDate>Thu, 17 Mar 2011 10:08:33 GMT</pubDate>
<title>Япония. Поможем пострадавшим.</title>
<link>http://xuma.livejournal.com/7831.html</link>
<description>...</description>
<comments>http://xuma.livejournal.com/7831.html</comments>
<lj:security>public</lj:security>
<lj:reply-count>0</lj:reply-count>
</item>
<item>
<guid isPermaLink="true">http://xuma.livejournal.com/7575.html</guid>
<pubDate>Sat, 16 Oct 2010 12:36:48 GMT</pubDate>
<link>http://xuma.livejournal.com/7575.html</link>
<description>
<h1>Тест личности</h1><br /><a href="http://teh-nomad.livejournal.com/667478.html"><img border="0" src="http://www.ljplus.ru/img4/a/s/astro_nomad/chtree_6.jpg" alt="" /></a><br /><br /><a href="http://teh-nomad.livejournal.com/667478.html">Выбрать себе дерево</a>
</description>
<comments>http://xuma.livejournal.com/7575.html</comments>
<lj:music>I chase the Devil</lj:music>
<media:title type="plain">I chase the Devil</media:title>
<lj:mood>опаздываю...</lj:mood>
<lj:security>public</lj:security>
<lj:reply-count>0</lj:reply-count>
</item>
</channel>
</rss>
这是我定义的bean:
@Root
public class RssType {
@Element(name="channel")
private ChannelType channel;
@Attribute
private String version;
public ChannelType getChannel() {
return channel;
}
public void setChannel(ChannelType channel) {
this.channel = channel;
}
public String getVersion() {
return version;
}
public void setVersion(String version) {
this.version = version;
}
}
@Element(name="channel")
public class ChannelType {
@Element
private String title;
@Element
private String link;
@Element
private String description;
@Element
private String lastBuildDate;
@Element
private String generator;
@Element
@Namespace(reference="http://www.livejournal.org/rss/lj/1.0/", prefix="lj")
private String journal;
@Element
@Namespace(reference="http://www.livejournal.org/rss/lj/1.0/", prefix="lj")
private String journalid;
@Element
@Namespace(reference="http://www.livejournal.org/rss/lj/1.0/", prefix="lj")
private String journaltype;
@Element
private ImageType image;
@ElementList(inline=false)
private List<ItemType> item;
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
public String getLink() {
return link;
}
public void setLink(String link) {
this.link = link;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
public String getLastBuildDate() {
return lastBuildDate;
}
public void setLastBuildDate(String lastBuildDate) {
this.lastBuildDate = lastBuildDate;
}
public String getGenerator() {
return generator;
}
public void setGenerator(String generator) {
this.generator = generator;
}
public String getJournal() {
return journal;
}
public void setJournal(String journal) {
this.journal = journal;
}
public String getJournalid() {
return journalid;
}
public void setJournalid(String journalid) {
this.journalid = journalid;
}
public String getJournaltype() {
return journaltype;
}
public void setJournaltype(String journaltype) {
this.journaltype = journaltype;
}
public ImageType getImage() {
return image;
}
public void setImage(ImageType image) {
this.image = image;
}
public List<ItemType> getItem() {
return item;
}
public void setItem(List<ItemType> item) {
this.item = item;
}
}
@Element(name="image")
public class ImageType {
@Element
private String url;
@Element
private String title;
@Element
private String link;
@Element
private String width;
@Element
private String height;
public String getUrl() {
return url;
}
public void setUrl(String url) {
this.url = url;
}
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
public String getLink() {
return link;
}
public void setLink(String link) {
this.link = link;
}
public String getWidth() {
return width;
}
public void setWidth(String width) {
this.width = width;
}
public String getHeight() {
return height;
}
public void setHeight(String height) {
this.height = height;
}
}
@Element(name="item")
public class ItemType {
@Element
private GuidType guid;
@Element
private String pubDate;
@Element
private String title;
@Element
private String link;
@Element
private String description;
@Element
private String comments;
@ElementList(inline=false)
private List<String> category;
@Element
@Namespace(reference="http://www.livejournal.org/rss/lj/1.0/", prefix="lj")
private String security;
@Element
@Namespace(reference="http://www.livejournal.org/rss/lj/1.0/", prefix="lj")
private String replyCount;
public GuidType getGuid() {
return guid;
}
public void setGuid(GuidType guid) {
this.guid = guid;
}
public String getPubDate() {
return pubDate;
}
public void setPubDate(String pubDate) {
this.pubDate = pubDate;
}
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
public String getLink() {
return link;
}
public void setLink(String link) {
this.link = link;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
public String getComments() {
return comments;
}
public void setComments(String comments) {
this.comments = comments;
}
public List<String> getCategory() {
return category;
}
public void setCategory(List<String> category) {
this.category = category;
}
public String getSecurity() {
return security;
}
public void setSecurity(String security) {
this.security = security;
}
public String getReplyCount() {
return replyCount;
}
public void setReplyCount(String replyCount) {
this.replyCount = replyCount;
}
}
@Element(name="guid")
public class GuidType {
@Attribute
public String isPermaLink;
public String text;
@Text
public String getText() {
return text;
}
@Text
public void setText(String text) {
this.text = text;
}
public String getIsPermaLink() {
return isPermaLink;
}
public void setIsPermaLink(String isPermaLink) {
this.isPermaLink = isPermaLink;
}
}
执行此代码:
String xmlData = retrieve("http://zuma.livejournal.com/data/rss");
Serializer serializer = new Persister();
RssType example = serializer.read(RssType.class, xmlData);
得到这样的异常
org.simpleframework.xml.core.AttributeException: Attribute 'isPermaLink' does not have a match in class com.ljclient.xml.beans.ItemType at line 22
但是isPermaLink不是 <item> 的属性节点但是<guid>节点。
如果我做了isPermaLink成为 <item> 的属性在这种情况下，我遇到以下异常:
org.simpleframework.xml.core.ValueRequiredException: Unable to satisfy @org.simpleframework.xml.ElementList(data=false, empty=true, entry=, inline=false, name=, required=true, type=void) on field 'category' private java.util.List com.ljclient.xml.beans.ItemType.category for class com.ljclient.xml.beans.ItemType at line 22
这很奇怪，因为每个类别节点都存在该值。有什么想法吗？
最佳答案
这不是对您问题的直接回答，但您是否尝试过创建 RssType 实例并将其写入 XML。此练习的重点是，您可以了解如何将标记转换为 XML 以解决任何明显的问题。
public static void main(String[] args) {
RssType rss = new RssType();
rss.setVersion("1.0");
ChannelType channel = new ChannelType();
channel.setTitle("Test title");
// Set the rest of the variables
rss.setChannel(channel);
//do the same for you other types then
//convert it to xml
Serializer serializer = new Persister();
File result = new File("rss.xml");
serializer.write(rss, result);
}
我知道这并不能立即解决问题，但它应该引导您确定问题所在。
好吧，我刚刚尝试过:
public static void main(String[] args) throws Exception {
ItemType item = new ItemType();
GuidType guid = new GuidType();
guid.setIsPermaLink("true");
guid.setText("http://zuma.livejournal.com/147000.html");
item.setGuid(guid);
item.setPubDate("Sun, 07 Oct 2012 06:43:24 GMT");
item.setTitle("tao machine");
item.setLink("http://zuma.livejournal.com/147000.html");
item.setDescription("><div class="qpp3"><div class="qpp4"><div class="qrbrdr1"><div class="qrbrdr2"><center><img src="http://zuma.vip.warped.com/transparent_8x8.png"><br><a title="http://stonedmotors.blogspot.com/2012/10/tao-machine.html" href="http://stonedmotors.blogspot.com/2012/10/tao-machine.html"><img src="http://zuma.vip.warped.com/stonedmotors2.png" border="0"></a><br><img src="http://zuma.vip.warped.com/transparent_8x8.png"></center></div></div><img src="http://zuma.vip.warped.com/transparent_8x8.png"><br><div class="a720"><div class="b720"><span class="tnr">midnight</span><br /><i>"dirt-tired, greased & wired, but the job's done, hey."</i><br /><br />the scattered tools upon the table, all in disarray. the wrenches, sockets, screwdrivers, extensions & adaptors, nuts & bolts & washers scrounged from the floor and about all (mostly) gathered in coffee cans... the piles of parts; case halves, studs, con rods & cranks, camshafts & shims, heads, manifolds, oil radiators, fan housings, distributors, coils, voltage regulators, generators & alternators, carbs & pistons, fuel pumps, filters, trannies, CV joints, axles, brake shoes, fuses, spark plugs, batteries, mufflers, belts, pulleys, flywheels... the cans of mineral spirits, carb cleaner, oil & gas; brake fluid... cleaning a set of wheel bearings w/ an air hose sets it spinning at umpteen hundred RPM. buckets of grease. pressure plates & throw-out bearings. clamps & hoses. breaker bars & torgue wrenches. plastigauge. pedal clusters. cables. shifter plates & bushings. tires, wheels, brake drums clanging, struck by a 5 pound sledge hammer. smoke from the ashtray curls up to the rafters. the coffee pot ticks. we laugh like mad children w/ dirt (like black soot) on our faces & elbows & old worn clothing in the midnight garage.</div></div><img src="http://zuma.vip.warped.com/transparent_8x8.png"><div class="zim"><div class="im1"><div class="im2"><a title="960x640 version" href="http://zuma.vip.warped.com/stomo8.png"><img src="http://zuma.vip.warped.com/stomo8_716x476.png" border="0"></a></div></div></div><img src="http://zuma.vip.warped.com/transparent_8x8.png"><div class="a720"><div class="b720">the eternal engine that moves us. forward.<br /><br /><i>"i could carve one from a rock..."</i><br /><br />crank it over. snick it in gear. let out the clutch. foot on the gas in Wide Open Throttle.<br /><br />stand on it.<br /></div></div></div></div>");
item.setComments("http://zuma.livejournal.com/147000.html");
item.setSecurity("public");
item.setReplyCount("8");
item.setCategory(new ArrayList<String>());
Serializer serializer = new Persister();
File result = new File("rss.xml");
serializer.write(item, result);
}
得到:
<itemType>
<guid isPermaLink="true">http://zuma.livejournal.com/147000.html</guid>
<pubDate>Sun, 07 Oct 2012 06:43:24 GMT</pubDate>
<title>tao machine</title>
<link>http://zuma.livejournal.com/147000.html</link>
<description>>&lt;div class=&quot;qpp3&quot;&gt;&lt;div class=&quot;qpp4&quot;&gt;&lt;div class=&quot;qrbrdr1&quot;&gt;&lt;div class=&quot;qrbrdr2&quot;&gt;&lt;center&gt;&lt;img src=&quot;http://zuma.vip.warped.com/transparent_8x8.png&quot;&gt;&lt;br&gt;&lt;a title=&quot;http://stonedmotors.blogspot.com/2012/10/tao-machine.html&quot; href=&quot;http://stonedmotors.blogspot.com/2012/10/tao-machine.html&quot;&gt;&lt;img src=&quot;http://zuma.vip.warped.com/stonedmotors2.png&quot; border=&quot;0&quot;&gt;&lt;/a&gt;&lt;br&gt;&lt;img src=&quot;http://zuma.vip.warped.com/transparent_8x8.png&quot;&gt;&lt;/center&gt;&lt;/div&gt;&lt;/div&gt;&lt;img src=&quot;http://zuma.vip.warped.com/transparent_8x8.png&quot;&gt;&lt;br&gt;&lt;div class=&quot;a720&quot;&gt;&lt;div class=&quot;b720&quot;&gt;&lt;span class=&quot;tnr&quot;&gt;midnight&lt;/span&gt;&lt;br /&gt;&lt;i&gt;&quot;dirt-tired, greased &amp; wired, but the job&apos;s done, hey.&quot;&lt;/i&gt;&lt;br /&gt;&lt;br /&gt;the scattered tools upon the table, all in disarray. the wrenches, sockets, screwdrivers, extensions &amp; adaptors, nuts &amp; bolts &amp; washers scrounged from the floor and about all (mostly) gathered in coffee cans... the piles of parts; case halves, studs, con rods &amp; cranks, camshafts &amp; shims, heads, manifolds, oil radiators, fan housings, distributors, coils, voltage regulators, generators &amp; alternators, carbs &amp; pistons, fuel pumps, filters, trannies, CV joints, axles, brake shoes, fuses, spark plugs, batteries, mufflers, belts, pulleys, flywheels... the cans of mineral spirits, carb cleaner, oil &amp; gas; brake fluid... cleaning a set of wheel bearings w/ an air hose sets it spinning at umpteen hundred RPM. buckets of grease. pressure plates &amp; throw-out bearings. clamps &amp; hoses. breaker bars &amp; torgue wrenches. plastigauge. pedal clusters. cables. shifter plates &amp; bushings. tires, wheels, brake drums clanging, struck by a 5 pound sledge hammer. smoke from the ashtray curls up to the rafters. the coffee pot ticks. we laugh like mad children w/ dirt (like black soot) on our faces &amp; elbows &amp; old worn clothing in the midnight garage.&lt;/div&gt;&lt;/div&gt;&lt;img src=&quot;http://zuma.vip.warped.com/transparent_8x8.png&quot;&gt;&lt;div class=&quot;zim&quot;&gt;&lt;div class=&quot;im1&quot;&gt;&lt;div class=&quot;im2&quot;&gt;&lt;a title=&quot;960x640 version&quot; href=&quot;http://zuma.vip.warped.com/stomo8.png&quot;&gt;&lt;img src=&quot;http://zuma.vip.warped.com/stomo8_716x476.png&quot; border=&quot;0&quot;&gt;&lt;/a&gt;&lt;/div&gt;&lt;/div&gt;&lt;/div&gt;&lt;img src=&quot;http://zuma.vip.warped.com/transparent_8x8.png&quot;&gt;&lt;div class=&quot;a720&quot;&gt;&lt;div class=&quot;b720&quot;&gt;the eternal engine that moves us. forward.&lt;br /&gt;&lt;br /&gt;&lt;i&gt;&quot;i could carve one from a rock...&quot;&lt;/i&gt;&lt;br /&gt;&lt;br /&gt;crank it over. snick it in gear. let out the clutch. foot on the gas in Wide Open Throttle.&lt;br /&gt;&lt;br /&gt;stand on it.&lt;br /&gt;&lt;/div&gt;&lt;/div&gt;&lt;/div&gt;&lt;/div&gt;</description>
<comments>http://zuma.livejournal.com/147000.html</comments>
<category class="java.util.ArrayList"/>
<lj:security xmlns:lj="http://www.livejournal.org/rss/lj/1.0/">public</lj:security>
<lj:replyCount xmlns:lj="http://www.livejournal.org/rss/lj/1.0/">8</lj:replyCount>
</itemType>
我注意到，如果未设置字段，我就会遇到异常。所以我简单地设置了一切。然后我编辑了 xml，如下所示:
<itemType>
<guid isPermaLink="true">http://zuma.livejournal.com/147000.html</guid>
<pubDate>Sun, 07 Oct 2012 06:43:24 GMT</pubDate>
<title>tao machine</title>
<link>http://zuma.livejournal.com/147000.html</link>
<description>>&lt;div class=&quot;qpp3&quot;&gt;&lt;div class=&quot;qpp4&quot;&gt;&lt;div class=&quot;qrbrdr1&quot;&gt;&lt;div class=&quot;qrbrdr2&quot;&gt;&lt;center&gt;&lt;img src=&quot;http://zuma.vip.warped.com/transparent_8x8.png&quot;&gt;&lt;br&gt;&lt;a title=&quot;http://stonedmotors.blogspot.com/2012/10/tao-machine.html&quot; href=&quot;http://stonedmotors.blogspot.com/2012/10/tao-machine.html&quot;&gt;&lt;img src=&quot;http://zuma.vip.warped.com/stonedmotors2.png&quot; border=&quot;0&quot;&gt;&lt;/a&gt;&lt;br&gt;&lt;img src=&quot;http://zuma.vip.warped.com/transparent_8x8.png&quot;&gt;&lt;/center&gt;&lt;/div&gt;&lt;/div&gt;&lt;img src=&quot;http://zuma.vip.warped.com/transparent_8x8.png&quot;&gt;&lt;br&gt;&lt;div class=&quot;a720&quot;&gt;&lt;div class=&quot;b720&quot;&gt;&lt;span class=&quot;tnr&quot;&gt;midnight&lt;/span&gt;&lt;br /&gt;&lt;i&gt;&quot;dirt-tired, greased &amp; wired, but the job&apos;s done, hey.&quot;&lt;/i&gt;&lt;br /&gt;&lt;br /&gt;the scattered tools upon the table, all in disarray. the wrenches, sockets, screwdrivers, extensions &amp; adaptors, nuts &amp; bolts &amp; washers scrounged from the floor and about all (mostly) gathered in coffee cans... the piles of parts; case halves, studs, con rods &amp; cranks, camshafts &amp; shims, heads, manifolds, oil radiators, fan housings, distributors, coils, voltage regulators, generators &amp; alternators, carbs &amp; pistons, fuel pumps, filters, trannies, CV joints, axles, brake shoes, fuses, spark plugs, batteries, mufflers, belts, pulleys, flywheels... the cans of mineral spirits, carb cleaner, oil &amp; gas; brake fluid... cleaning a set of wheel bearings w/ an air hose sets it spinning at umpteen hundred RPM. buckets of grease. pressure plates &amp; throw-out bearings. clamps &amp; hoses. breaker bars &amp; torgue wrenches. plastigauge. pedal clusters. cables. shifter plates &amp; bushings. tires, wheels, brake drums clanging, struck by a 5 pound sledge hammer. smoke from the ashtray curls up to the rafters. the coffee pot ticks. we laugh like mad children w/ dirt (like black soot) on our faces &amp; elbows &amp; old worn clothing in the midnight garage.&lt;/div&gt;&lt;/div&gt;&lt;img src=&quot;http://zuma.vip.warped.com/transparent_8x8.png&quot;&gt;&lt;div class=&quot;zim&quot;&gt;&lt;div class=&quot;im1&quot;&gt;&lt;div class=&quot;im2&quot;&gt;&lt;a title=&quot;960x640 version&quot; href=&quot;http://zuma.vip.warped.com/stomo8.png&quot;&gt;&lt;img src=&quot;http://zuma.vip.warped.com/stomo8_716x476.png&quot; border=&quot;0&quot;&gt;&lt;/a&gt;&lt;/div&gt;&lt;/div&gt;&lt;/div&gt;&lt;img src=&quot;http://zuma.vip.warped.com/transparent_8x8.png&quot;&gt;&lt;div class=&quot;a720&quot;&gt;&lt;div class=&quot;b720&quot;&gt;the eternal engine that moves us. forward.&lt;br /&gt;&lt;br /&gt;&lt;i&gt;&quot;i could carve one from a rock...&quot;&lt;/i&gt;&lt;br /&gt;&lt;br /&gt;crank it over. snick it in gear. let out the clutch. foot on the gas in Wide Open Throttle.&lt;br /&gt;&lt;br /&gt;stand on it.&lt;br /&gt;&lt;/div&gt;&lt;/div&gt;&lt;/div&gt;&lt;/div&gt;</description>
<comments>http://zuma.livejournal.com/147000.html</comments>
<lj:security xmlns:lj="http://www.livejournal.org/rss/lj/1.0/">public</lj:security>
<lj:replyCount xmlns:lj="http://www.livejournal.org/rss/lj/1.0/">8</lj:replyCount>
</itemType>
删除 ChannelType 值。当我尝试在做时读回它:
ItemType read = serializer.read(ItemType.class, new File("rss.xml"));
我得到:
Exception in thread "main" org.simpleframework.xml.core.ValueRequiredException: Unable to satisfy @org.simpleframework.xml.ElementList(entry=, name=, inline=false, data=false, empty=true, type=void, required=true) on field 'category' private java.util.List ItemType.category for class ItemType at line 1
at org.simpleframework.xml.core.Composite.validate(Composite.java:644)
at org.simpleframework.xml.core.Composite.readElements(Composite.java:449)
at org.simpleframework.xml.core.Composite.access$400(Composite.java:59)
at org.simpleframework.xml.core.Composite$Builder.read(Composite.java:1383)
at org.simpleframework.xml.core.Composite.read(Composite.java:201)
at org.simpleframework.xml.core.Composite.read(Composite.java:148)
at org.simpleframework.xml.core.Traverser.read(Traverser.java:92)
at org.simpleframework.xml.core.Persister.read(Persister.java:625)
at org.simpleframework.xml.core.Persister.read(Persister.java:606)
at org.simpleframework.xml.core.Persister.read(Persister.java:584)
at org.simpleframework.xml.core.Persister.read(Persister.java:543)
at org.simpleframework.xml.core.Persister.read(Persister.java:521)
at org.simpleframework.xml.core.Persister.read(Persister.java:426)
at Test.main(Test.java:31)
所以基本上它要求所有字段都在那里。因此需要将 @Element 和 @ElementList(inline=false) 注解更改为 @Element(required=false) 和 在任何可选字段上@ElementList(inline=false, required=false)。
关于java - SimpleXML 问题，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/13314269/