Latest fixes and solutions for java errors on FixDevs.https://fixdevs.com/enThu, 26 Mar 2026 00:00:00 GMThttps://fixdevs.com/blog/java-record-not-working/https://fixdevs.com/blog/java-record-not-working/How to fix Java record issues — compact constructor validation, custom accessor methods, Jackson serialization, inheritance restrictions, and when to use records vs regular classes.Thu, 26 Mar 2026 00:00:00 GMTjavabackenddebuggingbest-practicesFixDevshttps://fixdevs.com/blog/opentelemetry-not-working/https://fixdevs.com/blog/opentelemetry-not-working/How to fix OpenTelemetry issues — SDK initialization order, auto-instrumentation setup, OTLP exporter configuration, context propagation, and missing spans in Node.js, Python, and Java.Thu, 26 Mar 2026 00:00:00 GMTnodejspythonjavabackendobservabilitydebuggingFixDevshttps://fixdevs.com/blog/spring-boot-test-not-working/https://fixdevs.com/blog/spring-boot-test-not-working/How to fix Spring Boot test issues — @SpringBootTest vs test slices, MockMvc setup, @MockBean vs @Mock, test context caching, and common test configuration mistakes.Thu, 26 Mar 2026 00:00:00 GMTjavaspringtestingbackenddebuggingFixDevshttps://fixdevs.com/blog/spring-cache-not-working/https://fixdevs.com/blog/spring-cache-not-working/How to fix Spring Boot @Cacheable issues — @EnableCaching missing, self-invocation bypass, key generation, TTL configuration, cache eviction, and Caffeine vs Redis setup.Thu, 26 Mar 2026 00:00:00 GMTspring-bootjavabackenddebuggingperformanceFixDevshttps://fixdevs.com/blog/spring-data-jpa-query-not-working/https://fixdevs.com/blog/spring-data-jpa-query-not-working/How to fix Spring Data JPA query issues — JPQL vs native SQL, derived method naming, @Modifying for updates, pagination, projections, and LazyInitializationException.Wed, 25 Mar 2026 00:00:00 GMTspring-bootjavadatabasebackenddebuggingFixDevshttps://fixdevs.com/blog/spring-boot-transaction-not-rolling-back/https://fixdevs.com/blog/spring-boot-transaction-not-rolling-back/How to fix Spring @Transactional not rolling back — checked vs unchecked exceptions, self-invocation proxy bypass, rollbackFor, transaction propagation, and nested transactions.Sun, 22 Mar 2026 00:00:00 GMTspring-bootjavabackenddatabasedebuggingFixDevshttps://fixdevs.com/blog/java-hibernate-lazyinitializationexception/https://fixdevs.com/blog/java-hibernate-lazyinitializationexception/How to fix Hibernate LazyInitializationException — loading lazy associations outside an active session, fetch join, @Transactional scope, DTO projection, and Open Session in View.Thu, 19 Mar 2026 00:00:00 GMTjavaspring-boothibernatedebuggingbackendFixDevshttps://fixdevs.com/blog/spring-boot-failed-to-configure-datasource/https://fixdevs.com/blog/spring-boot-failed-to-configure-datasource/How to fix 'Failed to configure a DataSource: url attribute is not specified' in Spring Boot — adding database properties, excluding DataSource auto-configuration, H2 vs production DB setup, and multi-datasource configuration.Thu, 19 Mar 2026 00:00:00 GMTspring-bootjavadatabasedebuggingbackendFixDevshttps://fixdevs.com/blog/java-spring-circular-dependency/https://fixdevs.com/blog/java-spring-circular-dependency/How to fix Spring Boot circular dependency errors — BeanCurrentlyInCreationException, refactoring to break cycles, @Lazy injection, setter injection, and @PostConstruct patterns.Wed, 18 Mar 2026 00:00:00 GMTjavaspring-bootdebuggingbackendFixDevshttps://fixdevs.com/blog/java-spring-security-403/https://fixdevs.com/blog/java-spring-security-403/How to fix Spring Security 403 Forbidden errors — CSRF token missing, incorrect security configuration, method security blocking requests, and how to debug the Spring Security filter chain.Wed, 18 Mar 2026 00:00:00 GMTjavaspring-bootdebuggingbackendFixDevshttps://fixdevs.com/blog/spring-boot-datasource-failed/https://fixdevs.com/blog/spring-boot-datasource-failed/How to fix Spring Boot 'Failed to configure a DataSource' errors — missing URL property, driver class not found, connection refused, and how to correctly configure datasource properties for MySQL, PostgreSQL, and H2.Tue, 17 Mar 2026 00:00:00 GMTspring-bootjavadatabasedebuggingFixDevshttps://fixdevs.com/blog/gradle-could-not-resolve-dependencies/https://fixdevs.com/blog/gradle-could-not-resolve-dependencies/How to fix Gradle's 'Could not resolve all dependencies' error caused by missing repositories, offline mode, proxy issues, version conflicts, and corrupted cache.Tue, 10 Mar 2026 00:00:00 GMTgradlejavadebuggingFixDevshttps://fixdevs.com/blog/java-classcastexception/https://fixdevs.com/blog/java-classcastexception/How to fix Java ClassCastException by using instanceof checks, fixing generic type erasure, resolving ClassLoader conflicts, correcting raw types, and using pattern matching in Java 16+.Tue, 10 Mar 2026 00:00:00 GMTjavadebuggingFixDevshttps://fixdevs.com/blog/java-concurrentmodificationexception/https://fixdevs.com/blog/java-concurrentmodificationexception/How to fix Java ConcurrentModificationException caused by modifying a collection while iterating, HashMap concurrent access, stream operations, and multi-threaded collection usage.Mon, 09 Mar 2026 00:00:00 GMTjavadebuggingFixDevshttps://fixdevs.com/blog/java-illegalargumentexception/https://fixdevs.com/blog/java-illegalargumentexception/How to fix Java IllegalArgumentException caused by null arguments, invalid enum values, negative numbers, wrong format strings, and Spring/Hibernate validation failures.Mon, 09 Mar 2026 00:00:00 GMTjavadebuggingFixDevshttps://fixdevs.com/blog/java-nosuchmethoderror/https://fixdevs.com/blog/java-nosuchmethoderror/How to fix Java NoSuchMethodError caused by classpath conflicts, incompatible library versions, wrong dependency scope, shaded JARs, and compile vs runtime version mismatches.Mon, 09 Mar 2026 00:00:00 GMTjavadebuggingFixDevshttps://fixdevs.com/blog/java-nullpointerexception/https://fixdevs.com/blog/java-nullpointerexception/How to fix Java NullPointerException by reading stack traces, adding null checks, using Optional, fixing uninitialized variables, avoiding null returns, handling auto-unboxing, and using static analysis annotations.Mon, 09 Mar 2026 00:00:00 GMTjavadebuggingFixDevshttps://fixdevs.com/blog/java-spring-bean-creation-exception/https://fixdevs.com/blog/java-spring-bean-creation-exception/How to fix Spring BeanCreationException error creating bean caused by missing dependencies, circular references, wrong annotations, configuration errors, and constructor issues.Mon, 09 Mar 2026 00:00:00 GMTjavaspring-bootdebuggingFixDevshttps://fixdevs.com/blog/java-stackoverflowerror/https://fixdevs.com/blog/java-stackoverflowerror/How to fix java.lang.StackOverflowError caused by infinite recursion, circular references in toString or equals, JPA bidirectional relationships, and Spring circular dependencies.Mon, 09 Mar 2026 00:00:00 GMTjavadebuggingjvmFixDevshttps://fixdevs.com/blog/java-unsupportedclassversionerror/https://fixdevs.com/blog/java-unsupportedclassversionerror/How to fix Java UnsupportedClassVersionError caused by compiling with a newer JDK than the runtime, JAVA_HOME misconfiguration, and Maven/Gradle target version settings.Mon, 09 Mar 2026 00:00:00 GMTjavajdkFixDevshttps://fixdevs.com/blog/maven-could-not-resolve-dependencies/https://fixdevs.com/blog/maven-could-not-resolve-dependencies/How to fix Maven's 'Could not resolve dependencies' and 'Failed to read artifact descriptor' errors caused by corrupted cache, proxy settings, missing repositories, and version conflicts.Mon, 09 Mar 2026 00:00:00 GMTjavamavendebuggingFixDevshttps://fixdevs.com/blog/spring-boot-port-already-in-use/https://fixdevs.com/blog/spring-boot-port-already-in-use/How to fix the Spring Boot error 'Web server failed to start. Port 8080 was already in use' by killing blocking processes, changing ports, fixing IDE issues, and resolving Docker conflicts.Mon, 09 Mar 2026 00:00:00 GMTjavaspring-bootdebuggingFixDevshttps://fixdevs.com/blog/spring-boot-whitelabel-error-page/https://fixdevs.com/blog/spring-boot-whitelabel-error-page/How to fix the Spring Boot Whitelabel Error Page caused by missing controller mappings, wrong component scan, wrong package structure, and missing Thymeleaf templates.Mon, 09 Mar 2026 00:00:00 GMTjavaspring-bootFixDevshttps://fixdevs.com/blog/gradle-build-failed/https://fixdevs.com/blog/gradle-build-failed/How to fix Gradle build failures including dependency resolution errors, compilation failures, incompatible Java versions, and daemon issues.Fri, 27 Feb 2026 00:00:00 GMTgradlejavaandroidFixDevshttps://fixdevs.com/blog/java-outofmemoryerror/https://fixdevs.com/blog/java-outofmemoryerror/How to fix Java OutOfMemoryError including heap space, Metaspace, GC overhead limit exceeded, and unable to create new native thread.Wed, 04 Feb 2026 00:00:00 GMTjavaFixDevshttps://fixdevs.com/blog/java-classnotfoundexception/https://fixdevs.com/blog/java-classnotfoundexception/How to fix Java ClassNotFoundException at runtime by resolving missing dependencies, classpath issues, Maven/Gradle configuration, JDBC drivers, classloader problems, and Java module system errors.Fri, 09 Jan 2026 00:00:00 GMTjavamavengradleFixDevs