이 콘텐츠는 선택한 언어로 제공되지 않습니다.

53.2. Implementing the Message Interface


How to implement a custom message

Example 53.2, “Custom Message Implementation” outlines how to implement a message by extending the DefaultMessage class.

Example 53.2. Custom Message Implementation

import org.apache.camel.Exchange;
import org.apache.camel.impl.DefaultMessage;

public class CustomMessage extends DefaultMessage { 1

    public CustomMessage() { 2
        // Create message with default properties...
    }

    @Override
    public String toString() { 3
        // Return a stringified message...
    }

    @Override
    public CustomMessage newInstance() { 4
        return new CustomMessage( ... );
    }

    @Override
    protected Object createBody() { 5
        // Return message body (lazy creation).
    }

    @Override
    protected void populateInitialHeaders(Map<String, Object> map) { 6
        // Initialize headers from underlying message (lazy creation).
    }

    @Override
    protected void populateInitialAttachments(Map<String, DataHandler> map) { 7
        // Initialize attachments from underlying message (lazy creation).
    }
}
Copy to Clipboard Toggle word wrap
1
Implements a custom message class, CustomMessage, by extending the org.apache.camel.impl.DefaultMessage class.
2
Typically, you need a default constructor that creates a message with default properties.
3
Override the toString() method to customize message stringification.
4
The newInstance() method is called from inside the MessageSupport.copy() method. Customization of the newInstance() method should focus on copying all of the custom properties of the current message instance into the new message instance. The MessageSupport.copy() method copies the generic message properties by calling copyFrom().
5
The createBody() method works in conjunction with the MessageSupport.getBody() method to implement lazy access to the message body. By default, the message body is null. It is only when the application code tries to access the body (by calling getBody()), that the body should be created. The MessageSupport.getBody() automatically calls createBody(), when the message body is accessed for the first time.
6
The populateInitialHeaders() method works in conjunction with the header getter and setter methods to implement lazy access to the message headers. This method parses the message to extract any message headers and inserts them into the hash map, map. The populateInitialHeaders() method is automatically called when a user attempts to access a header (or headers) for the first time (by calling getHeader(), getHeaders(), setHeader(), or setHeaders()).
7
The populateInitialAttachments() method works in conjunction with the attachment getter and setter methods to implement lazy access to the attachments. This method extracts the message attachments and inserts them into the hash map, map. The populateInitialAttachments() method is automatically called when a user attempts to access an attachment (or attachments) for the first time by calling getAttachment(), getAttachments(), getAttachmentNames(), or addAttachment().
맨 위로 이동
Red Hat logoGithubredditYoutubeTwitter

자세한 정보

평가판, 구매 및 판매

커뮤니티

Red Hat 문서 정보

Red Hat을 사용하는 고객은 신뢰할 수 있는 콘텐츠가 포함된 제품과 서비스를 통해 혁신하고 목표를 달성할 수 있습니다. 최신 업데이트를 확인하세요.

보다 포괄적 수용을 위한 오픈 소스 용어 교체

Red Hat은 코드, 문서, 웹 속성에서 문제가 있는 언어를 교체하기 위해 최선을 다하고 있습니다. 자세한 내용은 다음을 참조하세요.Red Hat 블로그.

Red Hat 소개

Red Hat은 기업이 핵심 데이터 센터에서 네트워크 에지에 이르기까지 플랫폼과 환경 전반에서 더 쉽게 작업할 수 있도록 강화된 솔루션을 제공합니다.

Theme

© 2025 Red Hat