Programmer Group

In previous articles: Several ways for Spring Boot to read configuration , I introduced Java Bean-based parameter bindings in Spring Boot, identified on a Java Bean class with the @ConfigurationProperties annotation (more Spring Boot tutorials focus on the public number Java Technology Stack in the background reply: boot). A few days ago, Sprin ...

Differences between Hashtable, Collections.SynchronizedMap, and Concurrent HashMap thread security implementation principles and performance testing These three Map s are important collection classes in Java, and although the first two are less common, their comparison has become a high-frequency test point for Java interviews because of their ...

BUG background JDK: 11.0.4 Spring Cloud Finchley.SR3 Related configuration: #Enable hystrix feign.hystrix.enabled=true #Close the circuit breaker hystrix.command.default.circuitBreaker.enabled=false #Disable hystrix remote call timeout hystrix.command.default.execution.timeout.enabled=false hystrix.threadpool.default.coreSize=50 Hystrix isol ...

A protocol version error occurred while Archiva was running after successful installation: Caused by: javax.net.ssl.SSLException: Received fatal alert: protocol_version         at sun.security.ssl.Alerts.getSSLException(Alerts.java:208) ~[?:1.7.0_80]         at sun.security.ssl.Alerts.getSSLException(Alerts.java:154) ~[?:1.7.0_80]         at s ...

Master-Slave Synchronization Experimental preparation A total of four virtual machines, one application side, one amoeba, one master server, and one slave server Application side: centos7-2 (MySQL installed before the experiment) amoeba:centos7-1 (no MySQL) Primary server: centos7-3 (MySQL installed before the experiment) From server: centos ...

Netty's own ByteBuf ByteBuffer is designed to solve the problems of ByteBuffer and meet the daily needs of network application developers. Disadvantages of JDK ByteBuffer: Unable to expand dynamically: the length is fixed and cannot be expanded and contracted dynamically. When the data is larger than the ByteBuffer capacity, an index out of bo ...

1. Generate certificate Using jdk and keytool.exe in jre to generate self signed certificates requires the configuration of Java home and path environment variables, that is, jdk environment variables. The command is as follows: keytool -genkey -alias tomcat -storetype PKCS12 -keyalg RSA -keysize 2048 -keystore keystore.p12 -validity 3650 Th ...

Problem description A few days ago, I was helping my colleagues to troubleshoot the occasional thread pool errors on the production line The logic is simple, and the thread pool performs an asynchronous task with results. However, there have been occasional errors recently: java.util.concurrent.RejectedExecutionException: Task java.util.concurr ...

Originally, I wanted to learn about Netty components first, then learn about component applications. Then, learning more and more makes me feel weird. I always feel that there is something missing. I don't know how to use components when I learn them. Think about learning from Netty applications first. Own technology learning method: first ...

1. Introduction There are many difficult examples of Java class libraries, Collection must be one of them.Google first proposed the Guava library as an extension of the Java Collection to improve development efficiency.Over time, it has covered all aspects of Java development, and in Java 8, you can see that many API s are still learning from G ...