71 posts
This tutorial walks you through creating a custom Apache NiFi Processor project and writing your own processor to handle FlowFiles. Source code: https://github.com/renfei/demo/tree/master/nifi/nifi-custom-bundle
I previously wrote "The Big Pitfall of Reading Files After Packaging a Spring Boot Project Into a Jar: ClassPathResource Fails to Read Files on the Classpath" and published it on my blog and CSDN. I hadn't logged into CSDN in a long while; today I did, and found two commenters both saying they tried my approach and couldn't get anything.
As the web has evolved, more sites are served over HTTPS. The discuz-ucenter-api-for-java library that connects Discuz's UCenter to Java runs into trouble over HTTPS: it's a very old project that hasn't been updated in ages and doesn't support HTTPS endpoints. So I updated it.
I connected my Spring Boot main site with a Discuz! forum so login and logout are synchronized, and member data from Discuz! can be shown back on my site. I also modified the previously open-sourced discuz-ucenter-api-for-java to fit the way Spring Boot is written today.
The last post covered buying and configuring the server. This one is about Spring Boot optimization and technology choices: I switched to the more efficient FreeMarker, added Redis caching, added performance statistics, and added GitHub Actions workflows.
After upgrading to a newer Druid, the logs kept throwing errors: discard long time none received connection., jdbcUrl: blah blah. The program ran fine, but staring at a wall of errors is unbearable, so I went into their source to see what was actually going on.
When using the IDEA development tool, sometimes a Spring project's config files application.yml or bootstrap.yml aren't recognized properly — the icon isn't the green little leaf, causing the project to fail to start. At this point we need to manually check IDEA's configuration to fix it.
When using MyBatis, IDEA prompts 'Could not autowire. No beans of 'XXXMapper' type found.' and draws a red squiggly line on the mapper class. The actual reason is that you forgot to add the @Repository annotation to the mapper.
The .iml file is IntelliJ IDEA's project configuration file, containing some configuration info about the current project. Sometimes after importing a project you'll find that the .iml file isn't generated automatically, causing the project structure to not display properly. In that case we need to generate the .iml file manually.
Fastjson has a remote code execution vulnerability; the restriction of the autotype switch can be bypassed, and a chained deserialization attacker can craft a deserialization exploit chain, ultimately achieving remote command execution. This vulnerability itself cannot bypass Fastjson's blacklist restriction; it needs to be combined with a deserialization exploit chain not on the blacklist to complete the full exploitation.
