Springboot on Margrop Blog

Fixing CORS Issues When Upgrading from Spring 2.3.x to a Newer Version

Sun, 12 Mar 2023 20:20:01 +0800

Exception Message:

When allowCredentials is true, allowedOrigins cannot contain the special value "*" since that cannot be set on the "Access-Control-Allow-Origin" response header. To allow credentials to a set of origins, list them explicitly or consider using "allowedOriginPatterns" instead.

Solution:

CORS configuration error, simply replace .allowedOrigins with .allowedOriginPatterns.

Fixing SpringFox 3.0.0 Incompatibility with SpringBoot 2.6.4

Sun, 12 Mar 2023 17:56:57 +0800

Error Message:

Failed to start bean 'documentationPluginsBootstrapper'; nested exception is java.lang.NullPointerException

Root Cause Analysis:

SpringFox 3.0.0 is not compatible with SpringBoot 2.6.4

Solution:

Reference Links https://stackoverflow.com/questions/40241843/failed-to-start-bean-documentationpluginsbootstrapper-in-spring-data-rest https://github.com/springfox/springfox/issues/3462#issuecomment-1010721223

Java Spring Boot JNI Native Library Loader

Sat, 27 Mar 2021 16:37:31 +0800

Because Java needs to stay cross-platform, I wrote a cross-platform JNI native library loader.

Simple Implementation

Determine whether the current system is Windows, Linux, or MacOS from the os.name environment property.
If it is Linux, further determine whether it is CentOS or Debian.
Read the library files inside the jar package.
Filter the matching platform library files by file suffix: dll, so, jnilib, and dylib.
Copy the current platform’s library file to the system temporary directory java.io.tmpdir.
Load the library using System.load.

Spring Boot + Undertow upload file cannot find temporary directory

Sat, 27 Mar 2021 11:17:26 +0800

The problem occurs Two days ago, the company’s SpringBoot project suddenly had a problem of being unable to upload Excel files. After checking the Java log, I found a large number of exceptions: java.nio.file.NoSuchFileException: /tmp/undertow.12020.9432679758080410942/undertow17157208698492118168upload Detailed exception information is as follows: org.springframework.web.multipart.MultipartException: Failed to parse multipart servlet request; nested exception is java.lang.RuntimeException: java.nio.file.NoSuchFileException: /tmp/undertow.12020.9432679758080410942/undertow17157208698492118168upload at org.springframework.web.multipart.support.StandardMultipartHttpServletRequest.handleParseFailure(StandardMultipartHttpServletRequest.java:124) at org.springframework.web.multipart.support.StandardMultipartHttpServletRequest.parseRequest(StandardMultipartHttpServletRequest.java:115) at org.springframework.web.multipart.support.StandardMultipartHttpServletRequest.<init>(StandardMultipartHttpServletRequest.java:88) at org.springframework.web.multipart.support.StandardServletMultipartResolver.resolveMultipart(StandardServletMultipartResolver.java:87) at org.springframework.web.servlet.DispatcherServlet.checkMultipart(DispatcherServlet.java:1199) at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1033) at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:961) at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) at org.

The biggest pitfall of SpringBoot DevTools, none of them

Wed, 03 Mar 2021 18:23:39 +0800

Recently, a lot of changes have been added to the SpringBoot project, and then I encountered a very strange problem. HibernateDatabase query error This is simply weird Expected type and actual value are exactly the same, but Hibernate thinks they are different. How can this be fixed? After struggling with this strange problem for a day, I found that this only occurs on my local machine. The same code is completely normal on the test server.

[Transfer] Spring AOP intercepts classes or methods with specified annotation identifiers

Thu, 14 Jan 2021 15:29:41 +0800

Instructions for scanning specific annotations in AOP: (1) @annotation: intercepts all methods annotated with the target annotation. (2) @within: intercepts all classes annotated with the target annotation. (3) within: limits the package scope to scan. Code Demo @Aspect @Component @Order(10) public class BidAuthorityProxy { /** * Scan classes under the specified package that are annotated with `@EnableRoleAuthority`. */ @Around("@within(com.core.annotation.EnableRoleAuthority) && within(com.bid..*)") public Object verifyRoleExecuteCommand(ProceedingJoinPoint pjp) throws Throwable { // Get the intercepted method MethodSignature msig = (MethodSignature) pjp.