From 0abadf092936f2545ac9e9543289a27c60b51514 Mon Sep 17 00:00:00 2001
From: haogrgr <haogrgr@126.com>
Date: Wed, 15 Oct 2014 14:07:55 +0800
Subject: [PATCH] =?UTF-8?q?JAXBContext=E8=87=AA=E8=BA=AB=E6=98=AF=E7=BA=BF?=
 =?UTF-8?q?=E7=A8=8B=E5=AE=89=E5=85=A8=E7=9A=84,=E8=80=8C=E8=AF=A5?=
 =?UTF-8?q?=E5=AF=B9=E8=B1=A1=E5=88=9B=E5=BB=BA=E6=AF=94=E8=BE=83=E8=80=97?=
 =?UTF-8?q?=E6=97=B6,=E5=BE=AE=E4=BF=A1=E6=B6=88=E6=81=AF=E5=BA=8F?=
 =?UTF-8?q?=E5=88=97=E5=8C=96=E5=8F=8D=E5=BA=8F=E5=88=97=E5=8C=96=E9=9D=9E?=
 =?UTF-8?q?=E5=B8=B8=E9=A2=91=E7=B9=81,=E7=BC=93=E5=AD=98JAXBContext?=
 =?UTF-8?q?=E5=AF=B9=E8=B1=A1=E6=8F=90=E9=AB=98=E6=80=A7=E8=83=BD?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../weixin/util/xml/XmlTransformer.java       | 26 ++++++++++++++++---
 1 file changed, 23 insertions(+), 3 deletions(-)

diff --git a/src/main/java/me/chanjar/weixin/util/xml/XmlTransformer.java b/src/main/java/me/chanjar/weixin/util/xml/XmlTransformer.java
index b6fb5f2bf..49ff0516d 100644
--- a/src/main/java/me/chanjar/weixin/util/xml/XmlTransformer.java
+++ b/src/main/java/me/chanjar/weixin/util/xml/XmlTransformer.java
@@ -5,6 +5,8 @@ import java.io.InputStream;
 import java.io.StringReader;
 import java.io.StringWriter;
 import java.io.Writer;
+import java.util.HashMap;
+import java.util.Map;
 
 import javax.xml.bind.JAXBContext;
 import javax.xml.bind.JAXBException;
@@ -24,15 +26,17 @@ public class XmlTransformer {
    * @return
    * @throws JAXBException 
    */
+  @SuppressWarnings("unchecked")
   public static <T> T fromXml(Class<T> clazz, String xml) throws JAXBException {
-    JAXBContext context = JAXBContext.newInstance(clazz);
+    JAXBContext context = getJAXBContext(clazz);
     Unmarshaller um = context.createUnmarshaller();
     T object = (T) um.unmarshal(new StringReader(xml));
     return object;
   }
   
+  @SuppressWarnings("unchecked")
   public static <T> T fromXml(Class<T> clazz, InputStream is) throws JAXBException {
-    JAXBContext context = JAXBContext.newInstance(clazz);
+    JAXBContext context = getJAXBContext(clazz);
     Unmarshaller um = context.createUnmarshaller();
     InputSource inputSource = new InputSource(is);
     inputSource.setEncoding("utf-8");
@@ -53,7 +57,7 @@ public class XmlTransformer {
   }
   
   public static <T> void toXml(Class<T> clazz, T object, Writer writer) throws JAXBException {
-    JAXBContext context = JAXBContext.newInstance(clazz);
+    JAXBContext context = getJAXBContext(clazz);
     Marshaller m = context.createMarshaller();
     m.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
     m.setProperty(CharacterEscapeHandler.class.getName(), characterUnescapeHandler);
@@ -68,4 +72,20 @@ public class XmlTransformer {
     }
   }
   
+  protected static Map<Class<?>, JAXBContext> jaxbContexts = new HashMap<Class<?>, JAXBContext>();
+  
+  protected static JAXBContext getJAXBContext(Class<?> clazz){
+	//JAXBContext是线程安全的,且创建相对比较耗性能,使用map缓存,并发下多次创建没问题.
+	JAXBContext context = jaxbContexts.get(clazz);
+	if(context == null){
+	  try {
+	    context = JAXBContext.newInstance(clazz);
+	  } catch (JAXBException e) {
+	    throw new RuntimeException("创建JAXBContext实例失败:" + clazz.getName(), e);
+	  }
+	  jaxbContexts.put(clazz, context);
+	}
+	return context;
+  }
+  
 }