REST Web服务部署描述符查询Java

Question

am working on implementing Rest web service and need clarification on the deployment descriptor file. Below is the web.xml code and what I have understood is that whenever the url contains /webapi/ the ServletContainer class gets invoked. Please correct me if am wrong till this point. Further can you tell me what's the significance of the attributes param-name and param-value. Is it that the package mentioned in the param-value is passed as argument to the ServletContainer class?

<?xml version="1.0" encoding="UTF-8"?>
<!-- This web.xml file is not required when using Servlet 3.0 container,
     see implementation details http://jersey.java.net/nonav/documentation/latest/jax-rs.html -->
<web-app version="2.5" 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_2_5.xsd">
    <servlet>
        <servlet-name>Jersey Web Application</servlet-name>
        <servlet-class>org.glassfish.jersey.servlet.ServletContainer</servlet-class>
        <init-param>
            <param-name>jersey.config.server.provider.packages</param-name>
            <param-value>org.xyz.ws.transporter</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>Jersey Web Application</servlet-name>
        <url-pattern>/webapi/*</url-pattern>
    </servlet-mapping>
</web-app>

Thanks in advance for your help.

Answer 1

I have understood is that whenever the url contains /webapi/ the ServletContainer class gets invoked.

True.

Further can you tell me what's the significance of the attributes param-name and param-value

init-param s are basically just configuration properties that the servlet/filter can use to configure itself.

Here you are configuring a specific property named jersey.config.server.provider.packages , with the value of org.xyz.ws.transporter . Jersey will use the value of the this specific configuration property to set up package scanning. Jersey will scan the package you specify (recursively) for classes annotated with @Provider and @Path . This allows Jersey to register all resources and provider classes.