issue #9 提供xml消息的Builder

src/test/java/chanjarster/weixin/bean/WxXmlOutINewsMessageTest.java

@@ -45,4 +45,51 @@ public class WxXmlOutINewsMessageTest {
     Assert.assertEquals(m.toXml().replaceAll("\\s", ""), expected.replaceAll("\\s", ""));
   }
   
+  public void testBuild() {
+    WxXmlOutMewsMessage.Item item = new WxXmlOutMewsMessage.Item();
+    item.setDescription("description");
+    item.setPicUrl("picUrl");
+    item.setTitle("title");
+    item.setUrl("url");
+    
+    WxXmlOutMewsMessage m = WxXmlOutMessage.NEWS()
+          .fromUser("fromUser")
+          .touser("toUser")
+          .addArticle(item)
+          .addArticle(item)
+          .build();
+    String expected = "<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"yes\"?>" 
+        + "<xml>"
+        + "<ToUserName><![CDATA[toUser]]></ToUserName>"
+        + "<FromUserName><![CDATA[fromUser]]></FromUserName>"
+        + "<CreateTime>1122</CreateTime>"
+        + "<MsgType><![CDATA[news]]></MsgType>"
+        + "    <ArticleCount>2</ArticleCount>"
+        + "    <Articles>"
+        + "        <Item>"
+        + "            <Title><![CDATA[title]]></Title>"
+        + "            <Description><![CDATA[description]]></Description>"
+        + "            <PicUrl><![CDATA[picUrl]]></PicUrl>"
+        + "            <Url><![CDATA[url]]></Url>"
+        + "        </Item>"
+        + "        <Item>"
+        + "            <Title><![CDATA[title]]></Title>"
+        + "            <Description><![CDATA[description]]></Description>"
+        + "            <PicUrl><![CDATA[picUrl]]></PicUrl>"
+        + "            <Url><![CDATA[url]]></Url>"
+        + "        </Item>"
+        + "    </Articles>"
+        + "</xml>";
+    System.out.println(m.toXml());
+    Assert.assertEquals(
+        m
+        .toXml()
+        .replaceAll("\\s", "")
+        .replaceAll("<CreateTime>.*?</CreateTime>", ""), 
+        expected
+        .replaceAll("\\s", "")
+        .replaceAll("<CreateTime>.*?</CreateTime>", "")
+        );
+  }
+  
 }