Spring Applications

See the following topics for information:

Spring dependencies

• Only the following subset of the spring packages (Spring Framework version 3.1.0) are delivered with AS:
• org.springframework.ws spring-xml (version : 2.0.3.RELEASE)
• org.springframework spring-core (version : 3.1.0)
• org.springframework spring-beans (version : 3.1.0)
• org.springframework spring-context (version : 3.1.0)
• org.springframework spring-web (version : 3.1.0)
  
  
• If the Application needs any other spring packages, then those need to be deployed with application itself.
• Projects which are built with Spring 2.5 or higher versions will be backward compatible with delivered version of Spring Framework. However, it is recommended to build your application with Spring 3.1.0 before deployment.
• If the Application is based on a higher version of Spring framework, then that version needs to be deployed with the application. The framework which is deployed with the application will be given the priority in the run time.

CXF environment

• The following sub packages of Spring 3.0.7 are shipped with the Application Server CXF environment. 
• spring-aop
• spring-asm
• spring-beans
• spring-context
• spring-core
• spring-expression
• spring-web
  
  
• If the user wants to upgrade the Spring versions, one of the following actions can be carried out: 
• Remove existing Spring JARs from <product_home>/lib/runtimes/cxf directory and replace them with the new JARs.
• Include the required JARs inside the WEB-INF/lib directory of the application and deploy it in the Tomcat runtime environment.

Enabling CORS for Spring applications

If required, you can enable CORS (cross origin resource sharing) for spring applications by adding the CORS filter to the web.xml file as shown in the following example. 

<filter>
    <filter-name>CorsFilter</filter-name>
    <filter-class>org.apache.catalina.filters.CorsFilter</filter-class>
    <init-param>
        <param-name>cors.allowed.origins</param-name>
        <param-value>*</param-value>
    </init-param>
    <init-param>
        <param-name>cors.allowed.methods</param-name>
        <param-value>GET,POST,HEAD,OPTIONS,PUT,DELETE,PATCH</param-value>
    </init-param>
</filter>
<filter-mapping>
    <filter-name>CorsFilter</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>

The parameters used in this example are as follows:  

• The cors.allowed.origins parameter is used to specify the web domains that should be allowed to share resources with the spring application. The domain names should be specified as parameter values. If the parameter value is set to '*' as shown above, or if this parameter is not used at all, resource sharing will be allowed for all origins (all web domains). 
• The cors.allowed.methods parameter is used to specify the type of requests for which CORS should be enabled. You can list the allowed methods as parameter values.

Connecting to an application 

WSO2 AS supports a variety of transports . Among these, the HTTP  and HTTPS  servlet transports are used by the applications hosted on AS to connect with other clients and applications. The receiver implementation for the HTTP and HTTPS transports are built into Carbon products, and the sender implementation comes from the Tomcat http connector, which is configured in the catalina-server.xml file (stored in the <PRODUCT_HOME>/repository/conf/tomcat/ folder).