AbstractRequestContext上的google应用程序引擎NullPointerException。doFire(AbstractRequestContext.java:1102)
我刚开始使用谷歌AppEngine进行开发,现在我遇到了第一个问题
我从Google IO 2011中获取了Todo-Example-Project,并进行了一些更改,现在我在应用程序中获得了以下StackTrace:
Caused by: java.lang.NullPointerException: null
at com.google.web.bindery.requestfactory.shared.impl.AbstractRequestContext.doFire(AbstractRequestContext.java:1102)
at com.google.web.bindery.requestfactory.shared.impl.AbstractRequestContext.fire(AbstractRequestContext.java:569)
at com.google.web.bindery.requestfactory.shared.impl.AbstractRequest.fire(AbstractRequest.java:54)
at com.google.web.bindery.requestfactory.shared.impl.AbstractRequest.fire(AbstractRequest.java:59)
我尝试使用以下代码在GWT客户端中创建一个新实体:
MyRequest request = requestFactory.myRequest();
request.createTime().fire();
服务类中的代码
static DataStore db = new DataStore();
public static Time createTime() {
return db.update(new Time());
}
这是Datastore类中的代码
public Time update(Time item) {
PersistenceManager pm = PMF.get().getPersistenceManager();
try {
pm.makePersistent(item);
return item;
} finally {
pm.close();
}
}
我希望你能帮我解决这个问题
多谢各位
编辑: 我想我应该补充一点,当然我已经实现了一个TimeLocator类和一个ServiceLocator类
这是我的网站。xml,因为我认为可能存在以下问题:
<?xml version="1.0" encoding="utf-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/xmlschema-instance"
xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
xsi:schemalocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
version="2.5">
<!-- Default page to serve -->
<welcome-file-list>
<welcome-file>Test.html</welcome-file>
</welcome-file-list>
<!-- RequestFactory Servlet -->
<servlet>
<servlet-name>requestFactoryServlet</servlet-name>
<servlet-class>com.google.web.bindery.requestfactory.server.RequestFactoryServlet</servlet-class>
<init-param>
<param-name>symbolMapsDirectory</param-name>
<!-- You'll need to compile with -extras and move the symbolMaps directory
to this location if you want stack trace deobfuscation to work -->
<param-value>WEB-INF/classes/symbolMaps/</param-value>
</init-param>
</servlet>
<servlet-mapping>
<servlet-name>requestFactoryServlet</servlet-name>
<url-pattern>/gwtRequest</url-pattern>
</servlet-mapping>
<!-- Other servlets -->
<servlet>
<servlet-name>dataMessagingServlet</servlet-name>
<servlet-class>
com.google.安卓.c2dm.server.C2DMRetryServlet
</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>dataMessagingServlet</servlet-name>
<url-pattern>/tasks/c2dm</url-pattern>
</servlet-mapping>
<!-- Security -->
<!-- Require user login for the .html welcome page -->
<security-constraint>
<web-resource-collection>
<url-pattern>/Test.html</url-pattern>
</web-resource-collection>
<auth-constraint>
<role-name>*</role-name>
</auth-constraint>
</security-constraint>
<!-- Require admin role for the tasks servlet -->
<security-constraint>
<web-resource-collection>
<web-resource-name>tasks</web-resource-name>
<url-pattern>/tasks/*</url-pattern>
</web-resource-collection>
<auth-constraint>
<role-name>admin</role-name>
</auth-constraint>
</security-constraint>
</web-app>
# 1 楼答案
以下是启动RequestFactory以解决上述问题的方法:
# 2 楼答案
您是否正确地initialize了
RequestFactory
实例看起来您没有初始化的}
RequestTransport
:^{