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Package: com.helger.phase4.servlet
Maven artifact: com.helger.phase4:phase4-lib phase4 exposes a standard Jakarta Servlet for receiving AS4 messages. The servlet delegates to AS4XServletHandler for all processing logic.

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AS4Servlet

AS4Servlet extends AbstractXServlet and registers an AS4XServletHandler for HTTP POST requests. Multipart handling is disabled at the servlet level because phase4 manages it internally.
AS4Servlet is suitable when a single AS4 profile is served. For multiple profiles on one server, register multiple servlet mappings and configure the AS4XServletHandler accordingly. See Multi-Profile Handling.

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web.xml configuration

<servlet>
  <servlet-name>AS4Servlet</servlet-name>
  <servlet-class>com.helger.phase4.servlet.AS4Servlet</servlet-class>
</servlet>
<servlet-mapping>
  <servlet-name>AS4Servlet</servlet-name>
  <url-pattern>/as4</url-pattern>
</servlet-mapping>

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Spring Boot / Jakarta EE registration

import com.helger.phase4.servlet.AS4Servlet;
import jakarta.servlet.annotation.WebServlet;

@WebServlet(urlPatterns = "/as4")
public class MyAS4Servlet extends AS4Servlet {
    // Inherits all behavior from AS4Servlet
}

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AS4XServletHandler

AS4XServletHandler implements IXServletSimpleHandler and is the main incoming request processor.

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Constructor

new AS4XServletHandler()

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setRequestHandlerCustomizer

public AS4XServletHandler setRequestHandlerCustomizer(
    @Nullable IAS4ServletRequestHandlerCustomizer aHandlerCustomizer
)
Sets an optional customizer that is called before the incoming AS4RequestHandler is invoked. This gives you the opportunity to plug in custom behavior (e.g. custom P-Mode resolution, custom crypto factory) at the handler level.
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body.aHandlerCustomizer
IAS4ServletRequestHandlerCustomizer
The customizer implementation. Pass null to remove an existing customizer.

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getRequestHandlerCustomizer

@Nullable
public IAS4ServletRequestHandlerCustomizer getRequestHandlerCustomizer()
Returns the currently configured request handler customizer, or null if none is set.

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IAS4ServletRequestHandlerCustomizer

Package: com.helger.phase4.servlet Functional interface allowing injection of custom behavior into the AS4RequestHandler before it processes an incoming request. 
public interface IAS4ServletRequestHandlerCustomizer {
    void customizeBeforeHandling(
        @NonNull IRequestWebScopeWithoutResponse aRequestScope,
        @NonNull AS4UnifiedResponse aUnifiedResponse,
        @NonNull AS4RequestHandler aRequestHandler
    );
}

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Typical customizations via AS4RequestHandler

Inside the customizer you can call methods on AS4RequestHandler such as:
MethodDescription
setCryptoFactorySign(IAS4CryptoFactory)Override the signing crypto factory
setCryptoFactoryCrypt(IAS4CryptoFactory)Override the encryption crypto factory
setIncomingProfileSelector(IAS4IncomingProfileSelector)Override profile selection
setIncomingSecurityConfig(IAS4IncomingSecurityConfiguration)Override security configuration
setPModeResolver(IPModeResolver)Override P-Mode resolution

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Example: custom crypto factory per request

import com.helger.phase4.servlet.AS4XServletHandler;
import com.helger.phase4.servlet.IAS4ServletRequestHandlerCustomizer;

AS4XServletHandler handler = new AS4XServletHandler();
handler.setRequestHandlerCustomizer((requestScope, response, requestHandler) -> {
    // Inject a custom crypto factory based on request context
    requestHandler.setCryptoFactorySign(myCryptoFactory);
    requestHandler.setCryptoFactoryCrypt(myCryptoFactory);
});

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Default behavior

When no customizer is set, AS4XServletHandler uses:
  • Crypto factory: AS4CryptoFactoryConfiguration.getDefaultInstanceOrNull() (reads from application.properties)
  • P-Mode resolver: AS4DefaultPModeResolver.INSTANCE
  • Profile selector: AS4IncomingProfileSelectorConstant with the default profile from AS4Configuration.getDefaultAS4ProfileID()
  • Security configuration: Default AS4IncomingSecurityConfiguration

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