我有一个基本的JAXRS服务，我可以轻松地公开，但一次我希望使用依赖注入API，我怀疑Google Guice将是最好的之一。考虑到这一点，我试图整合它，但文档有点沉重，我不得不四处寻找尝试找到合适的组合
但是目前我从Google Guice收到错误，并且根据我是否使用@InjectParam注释而改变。
如果我使用@InjectParam注释，那么我得到
Mar 29, 2013 9:52:04 PM com.sun.jersey.spi.inject.Errors processErrorMessages
SEVERE: The following errors and warnings have been detected with resource and/or provider classes:
SEVERE: The class com.hillingar.server.dao.interfaces.UserDao is an interface and cannot be instantiated.
SEVERE: Missing dependency for constructor public com.hillingar.server.SessionUtility(com.hillingar.server.dao.interfaces.UserDao) at parameter index 0
如果我没有注释，那么我得到
Mar 29, 2013 9:54:59 PM com.sun.jersey.spi.inject.Errors processErrorMessages
SEVERE: The following errors and warnings have been detected with resource and/or provider classes:
SEVERE: Missing dependency for constructor public com.hillingar.server.rest.UserService(com.hillingar.server.dao.interfaces.UserDao,com.hillingar.server.SessionUtility) at parameter index 0
SEVERE: Missing dependency for constructor public com.hillingar.server.rest.UserService(com.hillingar.server.dao.interfaces.UserDao,com.hillingar.server.SessionUtility) at parameter index 1
这是我的web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
<filter>
<filter-name>guiceFilter</filter-name>
<filter-class>com.google.inject.servlet.GuiceFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>guiceFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<listener>
<listener-class>com.hillingar.server.ServletContextListener</listener-class>
</listener>
<session-config>
<session-timeout>
30
</session-timeout>
</session-config>
</web-app>
这是我的ServletContextListener
package com.hillingar.server;
import java.util.logging.Logger;
import javax.servlet.ServletContextEvent;
import com.google.inject.Guice;
import com.google.inject.Singleton;
import com.hillingar.server.dao.jdbcImpl.UserJdbc;
import com.hillingar.server.dao.interfaces.UserDao;
import com.sun.jersey.guice.JerseyServletModule;
import com.sun.jersey.guice.spi.container.servlet.GuiceContainer;
import com.sun.jersey.spi.container.servlet.ServletContainer;
public class ServletContextListener implements javax.servlet.ServletContextListener {
Logger logger = Logger.getLogger(this.getClass().getName());
@Override
public void contextDestroyed(ServletContextEvent arg0) {
}
/*
* Covered in URL
* https://code.google.com/p/google-guice/wiki/ServletModule
*/
@Override
public void contextInitialized(ServletContextEvent arg0) {
// Note the user of JerseyServletModule instead of ServletModule
// otherwise the expected constructor injection doesn't happen
// (just the default constructor is called)
Guice.createInjector(new JerseyServletModule() {
@Override
protected void configureServlets() {
/*
* Note: Every servlet (or filter) is required to be a
* @Singleton. If you cannot annotate the class directly,
* you must bind it using bind(..).in(Singleton.class),
* separate to the filter() or servlet() rules.
* Mapping under any other scope is an error. This is to
* maintain consistency with the Servlet specification.
* Guice Servlet does not support the
* deprecated SingleThreadModel.
*/
bind(SecurityFilter.class).in(Singleton.class);
bind(ServletContainer.class).in(Singleton.class);
/*
* Filter Mapping
*
* This will route every incoming request through MyFilter,
* and then continue to any other matching filters before
* finally being dispatched to a servlet for processing.
*
*/
// SECURITY - currently disabled
// filter("/*").through(SecurityFilter.class);
/*
* Registering Servlets
*
* This registers a servlet (subclass of HttpServlet) called
* ServletContainer, the same one that I would have used in
* the web.xml file, to serve any web requests with the
* path /rest/* i.e. ...
*
<servlet>
<servlet-name>ServletAdaptor</servlet-name>
<servlet-class>com.sun.jersey.spi.container.servlet.ServletContainer</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>ServletAdaptor</servlet-name>
<url-pattern>/rest/*</url-pattern>
</servlet-mapping>
*/
serve("/rest/*").with(ServletContainer.class); // JAX-RS
// Using this and it starts bitching about
// com.sun.jersey.api.container.ContainerException: The ResourceConfig instance does not contain any root resource classes.
// So presumably wants an Application class that enumerates
// all my services?
//serve("/rest/*").with(GuiceContainer.class);
/*
* Bindings
*/
bind(UserDao.class).to(UserJdbc.class);
bind(SessionUtility.class);
}
});
}
}
这是我的UserService
package com.hillingar.server.rest;
import com.google.inject.Inject;
import com.google.inject.Singleton;
import java.util.List;
import javax.servlet.http.HttpServletRequest;
import javax.ws.rs.Consumes;
import javax.ws.rs.GET;
import javax.ws.rs.POST;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.Produces;
import javax.ws.rs.core.Context;
import javax.ws.rs.core.SecurityContext;
import com.hillingar.server.SessionUtility;
import com.hillingar.server.dao.interfaces.UserDao;
import com.hillingar.server.model.User;
import com.hillingar.server.model.dto.AuthenticationResponse;
@Path("/user")
@Produces("application/json")
@Consumes({"application/xml","application/json"})
@Singleton // <-- Added Singleton here
public class UserService {
private UserDao userDao;
private SessionUtility sessionManager;
/*
Error if I annotate with @InjectParam...
Mar 29, 2013 9:52:04 PM com.sun.jersey.spi.inject.Errors processErrorMessages
SEVERE: The following errors and warnings have been detected with resource and/or provider classes:
SEVERE: The class com.hillingar.server.dao.interfaces.UserDao is an interface and cannot be instantiated.
SEVERE: Missing dependency for constructor public com.hillingar.server.SessionUtility(com.hillingar.server.dao.interfaces.UserDao) at parameter index 0
Error If I don't annotate at all...
Mar 29, 2013 9:54:59 PM com.sun.jersey.spi.inject.Errors processErrorMessages
SEVERE: The following errors and warnings have been detected with resource and/or provider classes:
SEVERE: Missing dependency for constructor public com.hillingar.server.rest.UserService(com.hillingar.server.dao.interfaces.UserDao,com.hillingar.server.SessionUtility) at parameter index 0
SEVERE: Missing dependency for constructor public com.hillingar.server.rest.UserService(com.hillingar.server.dao.interfaces.UserDao,com.hillingar.server.SessionUtility) at parameter index 1
(both output Initiating Jersey application, version 'Jersey: 1.13 06/29/2012 05:14 PM')
*/
@Inject
public UserService(UserDao userDao, SessionUtility sessionManager) {
this.userDao = userDao;
this.sessionManager = sessionManager;
}
@GET
public List<User> test(@Context HttpServletRequest hsr) {
// USER DAO IS ALWAYS NULL - CONSTRUCTOR INJECTION NOT WORKING
User loggedInUser = userDao.findBySessionId(hsr.getSession().getId());
...
return users;
}
}
答案 0 :(得分：5)
将ServletContextListener更改为
package com.hillingar.server;
import java.util.logging.Logger;
import javax.servlet.ServletContextEvent;
import com.google.inject.Guice;
import com.google.inject.Injector;
import com.google.inject.Singleton;
import com.google.inject.servlet.GuiceServletContextListener;
import com.hillingar.server.dao.jdbcImpl.UserJdbc;
import com.hillingar.server.dao.interfaces.UserDao;
import com.hillingar.server.rest.UserService;
import com.sun.jersey.guice.JerseyServletModule;
import com.sun.jersey.guice.spi.container.servlet.GuiceContainer;
import com.sun.jersey.spi.container.servlet.ServletContainer;
// (1) Extend GuiceServletContextListener
public class ServletContextListener extends GuiceServletContextListener {
Logger logger = Logger.getLogger(this.getClass().getName());
// (1) Override getInjector
@Override
protected Injector getInjector() {
return Guice.createInjector(new JerseyServletModule() {
@Override
protected void configureServlets() {
bind(SecurityFilter.class).in(Singleton.class);
bind(UserService.class);// .in(Singleton.class);
bind(ServletContainer.class).in(Singleton.class);
// (2) Change to using the GuiceContainer
serve("/rest/*").with(GuiceContainer.class); // <<<<---
bind(UserDao.class).to(UserJdbc.class);
bind(SessionUtility.class);
}
});
}
}