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A library to simplify iOS animations in Swift.


Downloading a file from spring controllers

I have a requirement where I need to download a PDF from the website, the PDF needs to be generated within the code, which I thought would be a combination of freemarker and a PDF generation framework like iText (any better way?). However my main problem is how do I allow the user to download a file through a Spring Controller?


Source: (StackOverflow)

Why would I use Scala/Lift over Java/Spring? [closed]

I know this question is a bit open but I have been looking at Scala/Lift as an alternative to Java/Spring and I wonder what are the real advantages that Scala/Lift has over it. From my perspective and experience, Java Annotations and Spring really minimizes the amount of coding that you have to do for an application. Does Scala/Lift improve upon that?


Source: (StackOverflow)

Difference between applicationContext.xml and spring-servlet.xml in Spring

Are applicationContext.xml and spring-servlet.xml related anyhow in spring framework? Will the properties files declared in applicationContext.xml be available to DispatcherServlet? On a related note, why do I need a *-servlet.xml at all ? Why is applicationContext.xml alone insufficient?


Source: (StackOverflow)

What exactly is Spring for?

I hear a lot about spring, people are saying all over the web that Spring is a good framework for web development. But what exactly is it for? How can I use it for my Web-Java application development? any examples ?.


Source: (StackOverflow)

How does autowiring work in Spring?

I'm a little confused as to how the inversion of control (IoC) works in Spring.

Say I have a service class called UserServiceImpl that implements UserService interface.

How would this be @Autowired?

And in my Controllers action, how would I instantiate an instance of this service?

Would I just do the following?

UserService userService = new UserServiceImpl();

Source: (StackOverflow)

How can I inject a property value into a Spring Bean which was configured using annotations?

I have a bunch of Spring beans which are picked up from the classpath via annotations, e.g.

@Repository("personDao")
public class PersonDaoImpl extends AbstractDaoImpl implements PersonDao {
    // Implementation omitted
}

In the Spring XML file, there's a PropertyPlaceholderConfigurer defined:

<bean id="propertyConfigurer" 
  class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
    <property name="location" value="/WEB-INF/app.properties" />
</bean> 

I want to inject one of the properties from app.properites into the bean shown above. I can't simply do something like

<bean class="com.example.PersonDaoImpl">
    <property name="maxResults" value="${results.max}"/>
</bean>

Because PersonDaoImpl does not feature in the Spring XML file (it is picked up from the classpath via annotations). I've got as far as the following:

@Repository("personDao")
public class PersonDaoImpl extends AbstractDaoImpl implements PersonDao {

    @Resource(name = "propertyConfigurer")
    protected void setProperties(PropertyPlaceholderConfigurer ppc) {
    // Now how do I access results.max? 
    }
}

But it's not clear to me how I access the property I'm interested in from ppc?


Source: (StackOverflow)

Spring @Autowired usage

What are the pros and cons of using @Autowired in a class that will be wired up by Spring?

Just to clarify, I'm talking specifically about the @Autowired annotation, not auto-wiring in XML.

I probably just don't understand it, but to me it almost seems like an anti-pattern - your classes start to become aware that they are tied to a DI framework, rather than just being POJOs. Maybe I'm a glutton for punishment, but I like having the external XML config for beans, and I like to have explicit wirings, so I know exactly what is wired where.


Source: (StackOverflow)

java.lang.ClassNotFoundException: org.springframework.web.context.ContextLoaderListener

I included:

  • all Spring libs,

  • Apache Tomcat 7.0 library

    in Build Path

but it still gives errors:

SEVERE: Error configuring application listener of class org.springframework.web.context.ContextLoaderListener
java.lang.ClassNotFoundException: org.springframework.web.context.ContextLoaderListener
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1676)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1521)
    at org.apache.catalina.core.DefaultInstanceManager.loadClass(DefaultInstanceManager.java:415)
    at org.apache.catalina.core.DefaultInstanceManager.loadClassMaybePrivileged(DefaultInstanceManager.java:397)
    at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:118)
    at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4660)
    at org.apache.catalina.core.StandardContext$1.call(StandardContext.java:5226)
    at org.apache.catalina.core.StandardContext$1.call(StandardContext.java:5221)
    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
    at java.util.concurrent.FutureTask.run(FutureTask.java:138)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
    at java.lang.Thread.run(Thread.java:662)
Jun 2, 2011 11:07:38 AM org.apache.catalina.core.StandardContext listenerStart
SEVERE: Error configuring application listener of class org.springframework.web.context.request.RequestContextListener
java.lang.ClassNotFoundException: org.springframework.web.context.request.RequestContextListener
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1676)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1521)
    at org.apache.catalina.core.DefaultInstanceManager.loadClass(DefaultInstanceManager.java:415)
    at org.apache.catalina.core.DefaultInstanceManager.loadClassMaybePrivileged(DefaultInstanceManager.java:397)
    at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:118)
    at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4660)
    at org.apache.catalina.core.StandardContext$1.call(StandardContext.java:5226)
    at org.apache.catalina.core.StandardContext$1.call(StandardContext.java:5221)
    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
    at java.util.concurrent.FutureTask.run(FutureTask.java:138)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
    at java.lang.Thread.run(Thread.java:662)
Jun 2, 2011 11:07:38 AM org.apache.catalina.core.StandardContext listenerStart
SEVERE: Error configuring application listener of class com.sun.faces.config.ConfigureListener
java.lang.ClassNotFoundException: com.sun.faces.config.ConfigureListener
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1676)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1521)
    at org.apache.catalina.core.DefaultInstanceManager.loadClass(DefaultInstanceManager.java:415)
    at org.apache.catalina.core.DefaultInstanceManager.loadClassMaybePrivileged(DefaultInstanceManager.java:397)
    at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:118)
    at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4660)
    at org.apache.catalina.core.StandardContext$1.call(StandardContext.java:5226)
    at org.apache.catalina.core.StandardContext$1.call(StandardContext.java:5221)
    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
    at java.util.concurrent.FutureTask.run(FutureTask.java:138)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
    at java.lang.Thread.run(Thread.java:662)

In "org.sprintframework.web-3.1.0.M1.jar", I can see "org.springframework.web.context.ContextLoaderListener".

Someone on Google says that spring.jar should be included but I don't see any spring.jar in 3.x distribution.

Eclipse 3.6.2 Tomcat 7

Edit: Someone says "Automatically update dependencies" should be checked in Project Properties but I don't see anything like that in project properties. ClassNotFoundException:org.springframework.web.con text.ContextLoaderListener


Source: (StackOverflow)

Spring - How to call a method after bean initialization is complete?

I have a use case where I need to call a (non-static) method in the bean only-once at the ApplicationContext load up. Is it ok, if I use MethodInvokingFactoryBean for this? Or we have a some better solution?

As a side note, I use ConfigContextLoaderListener to load the Application Context in web application. And want, that if bean 'A' is instantiated just call methodA() once.

How can this be done nicely?


Source: (StackOverflow)

Getting Spring Application Context

Is there a way to statically/globally request a copy of the ApplicationContext in a Spring application?

Assuming the main class starts up and initializes the application context, does it need to pass that down through the call stack to any classes that need it, or is there a way for a class to ask for the previously created context? (Which I assume has to be a singleton?)


Source: (StackOverflow)

Spring Security on Wildfly / Undertow: error executing the filter chain

I'm working in order to integrate Spring Security SAML Extension with Spring Boot.

I developed a complete sample application, all the source code is published on GitHub:

By running the WebApp as Spring Boot application (through Spring Tool Set, by using an embedded Application Server), it works fine. Unfortunately, the auth process doesn't work on Undertow/WildFly (and I must use it as production AS).

By logging, I can see that the IdP performs the AuthN process and the instructions of my custom UserDetails implementation are correctly executed. Despite that Spring doesn't set up the privileges for the current user.

@Component
public class SAMLUserDetailsServiceImpl implements SAMLUserDetailsService {

    // Logger
    private static final Logger LOG = LoggerFactory.getLogger(SAMLUserDetailsServiceImpl.class);

    @Override
    public Object loadUserBySAML(SAMLCredential credential)
            throws UsernameNotFoundException, SSOUserAccountNotExistsException {
        String userID = credential.getNameID().getValue();
        if (userID.compareTo("jdoe@samplemail.com") != 0) {     // We're simulating the data access.
            LOG.warn("SSO User Account not found into the system");
            throw new SSOUserAccountNotExistsException("SSO User Account not found into the system", userID);
        }
        LOG.info(userID + " is logged in");
        List<GrantedAuthority> authorities = new ArrayList<GrantedAuthority>();
        GrantedAuthority authority = new SimpleGrantedAuthority("ROLE_USER");
        authorities.add(authority);
        ExtUser userDetails = new ExtUser(userID, "password", true, true, true,
                true, authorities, "John", "Doe");
        return userDetails;
    }
}

By debugging, I checked that the problem starts from the FilterChainProxy class. When I run the webapp on WildFly, I can see that the attribute FILTER_APPLIED of ServletRequest is null, thus Spring clears the SecurityContextHolder.

private final static String FILTER_APPLIED = FilterChainProxy.class.getName().concat(".APPLIED");

public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
        throws IOException, ServletException {
    boolean clearContext = request.getAttribute(FILTER_APPLIED) == null;
    if (clearContext) {
        try {
            request.setAttribute(FILTER_APPLIED, Boolean.TRUE);
            doFilterInternal(request, response, chain);
        } finally {
            SecurityContextHolder.clearContext();
            request.removeAttribute(FILTER_APPLIED);
        }
    } else {
        doFilterInternal(request, response, chain);
    }
}

On VMware vFabric tc Sever and Tomcat that doesn't happen. Is there a way to resolve this issue?


Source: (StackOverflow)

Unsure if I understand TransactionAwarePersistenceManagerFactoryProxy

I am trying to use the org.springframework.orm.jdo.TransactionAwarePersistenceManagerFactoryProxy in my Spring project, but I am not sure how to use it or whether it's exactly what I am looking for. I realize it can help make my DAOs work with a plain JDO PersistenceManagerFactory. Another question is: what happens if the proxy doesn't get made properly? Can I still use it to access my factory to create a transaction aware persistence manager? If the object managed by the factory is a singleton, does this change things? Why not just access the PersistenceManagerFactory directly? Perhaps PersistenceManagerFactoryUtils.getPersistenceManager would be more suited to my needs? Can getObject return null?


Source: (StackOverflow)

When using Spring Security, what is the proper way to obtain current username (i.e. SecurityContext) information in a bean?

I have a Spring MVC web app which uses Spring Security. I want to know the username of the currently logged in user. I'm using the code snippet given below . Is this the accepted way?

I don't like having a call to a static method inside this controller - that defeats the whole purpose of Spring, IMHO. Is there a way to configure the app to have the current SecurityContext, or current Authentication, injected instead?

  @RequestMapping(method = RequestMethod.GET)
  public ModelAndView showResults(final HttpServletRequest request...) {
    final String currentUser = SecurityContextHolder.getContext().getAuthentication().getName();
    ...
  }

Source: (StackOverflow)

Why is Spring's ApplicationContext.getBean considered bad?

I asked a general Spring question: Auto-cast Spring Beans and had multiple people respond that calling Spring's ApplicationContext.getBean() should be avoided as much as possible. Why is that?

How else should I gain access to the beans I configured Spring to create?

I'm using Spring in a non-web application and had planned on accessing a shared ApplicationContext object as described by LiorH.

Amendment

I accept the answer below, but here's an alternate take by Martin Fowler who discusses the merits of Dependency Injection vs. using a Service Locator (which is essentially the same as calling a wrapped ApplicationContext.getBean()).

In part, Fowler states, "With service locator the application class asks for it [the service] explicitly by a message to the locator. With injection there is no explicit request, the service appears in the application class - hence the inversion of control. Inversion of control is a common feature of frameworks, but it's something that comes at a price. It tends to be hard to understand and leads to problems when you are trying to debug. So on the whole I prefer to avoid it [Inversion of Control] unless I need it. This isn't to say it's a bad thing, just that I think it needs to justify itself over the more straightforward alternative."


Source: (StackOverflow)

Spring 3.0 - Unable to locate Spring NamespaceHandler for XML schema namespace [http://www.springframework.org/schema/security]

Any ideas what could be the cause of this?

Unable to locate Spring NamespaceHandler for XML schema namespace [http://www.springframework.org/schema/security]

org.springframework.web.context.ContextLoader initWebApplicationContext: Context initialization failed
org.springframework.beans.factory.parsing.BeanDefinitionParsingException: Configuration problem: Unable to locate Spring NamespaceHandler for XML schema namespace [http://www.springframework.org/schema/security]
Offending resource: ServletContext resource [/WEB-INF/applicationContext.xml]

This is my applicationContext.xml:

<?xml version="1.0" encoding="UTF-8"?>
<beans:beans xmlns="http://www.springframework.org/schema/security"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:beans="http://www.springframework.org/schema/beans"
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
        http://www.springframework.org/schema/context 
        http://www.springframework.org/schema/context/spring-context-3.0.xsd
        http://www.springframework.org/schema/security
        http://www.springframework.org/schema/security/spring-security-3.0.xsd">
...
</beans:beans>

In my pom.xml I have:

<dependency>
    <groupId>org.springframework.security</groupId>
    <artifactId>spring-security-core</artifactId>      
    <version>3.0.1.RELEASE</version>
</dependency>
<dependency>
    <groupId>org.springframework.security</groupId>
    <artifactId>spring-security-openid</artifactId>
    <version>3.0.1.RELEASE</version>
</dependency>

Source: (StackOverflow)