Java web crawler has several advantages when it comes to data collection. Here are some of the key benefits:

1. Robustness and Stability: Java is known for its robustness and stability, making it a reliable choice for web crawling. It can handle large-scale data collection tasks and is less likely to crash or encounter errors compared to other languages.

2. Platform Independence: Java is a platform-independent language, which means that a Java web crawler can run on any operating system without modification. This makes it easier to deploy and maintain the web crawler across different environments.

3. Rich Ecosystem: Java has a rich ecosystem of libraries and frameworks that can be leveraged for web crawling. For example, libraries like Jsoup and Selenium provide powerful tools for parsing and interacting with web pages, making it easier to extract the desired data.

4. Multithreading Support: Java has built-in support for multithreading, allowing web crawlers to perform multiple tasks concurrently. This can significantly improve the efficiency of data collection by fetching and processing multiple web pages simultaneously.

5. Performance: Java is known for its performance, especially when it comes to CPU-intensive tasks. This can be beneficial for web crawlers that need to process large volumes of data quickly.

6. Community Support: Java has a large and active community of developers, which means that there is a wealth of resources and support available for web crawling projects. Developers can easily find help, documentation, and third-party libraries to aid in their web crawling endeavors.

7. Security: Java's built-in security features make it a suitable choice for web crawling tasks that involve handling sensitive data. With proper implementation, Java web crawlers can ensure data privacy and protection against security threats.

In conclusion, Java offers several advantages for web crawling, including robustness, platform independence, rich ecosystem, multithreading support, performance, community support, and security features. These factors make Java a compelling choice for data collection tasks that require reliability, scalability, and efficiency.