website·Indexed 31 days ago
https://bkbk-site.netlify.appA technical knowledge base covering Java development, including JVM structure, Spring, Spring Cloud, MyBatis, Redis, and RocketMQ. The site also features guides on Vue, algorithm implementations (such as Quicksort and KMP), and deployment tutorials for ECS and FTP.
Spring Cloud Gateway is the second-generation gateway for Spring Cloud, designed to replace Zuul. It is built on Netty, Reactor, and WebFlux, providing high performance (approximately 1.6x that of Zuul 1.x) and built-in features for request forwarding, monitoring, and rate limiting.
Key constraints and requirements:
Class object that contains metadata about the class. This object is created when the .class file is loaded into the JVM at runtime. A single Class instance exists per loaded class in the JVM. The Class object serves as the entry point for the Reflection API, allowing programs to dynamically inspect and manipulate classes.Redis (Remote Dictionary Server) is an open-source, in-memory, key-value NoSQL database written in ANSI C. It supports network access and persistence via RDB and AOF. While traditionally single-threaded (using I/O multiplexing to handle concurrency), version 6.x introduced multi-threading support.
Core Data Types:
Specialized Data Types:
spring-cloud-starter-stream-rocketmq to implement a message-driven architecture. This requires the @EnableBinding(Source.class) annotation on the startup class and using the Source interface to send messages.<!-- Dependency -->
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-starter-stream-rocketmq</artifactId>
</dependency># Configuration
cloud:
stream:
rocketmq:
binder:
name-server: 192.168.78.134:9876
group: mail-group
bindings:
output:
destination: mail-group// Startup class
@EnableBinding(Source.class)
@SpringBootApplication
public class Application { ... }
// Service implementation
@Autowired
private Source source;
@GetMapping("/mail")
public ResultVo mail(){
source.output().send(MessageBuilder.withPayload("group mail aaaa").build());
return ResultVo.DEFAULT_SUCCESS;
}spring-cloud-starter-stream-rocketmq to implement a message-driven architecture using Spring Cloud Stream bindings. This approach uses Source for producing messages and Sink for consuming them.<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-starter-stream-rocketmq</artifactId>
</dependency>cloud: stream: rocketmq: binder: name-server: 192.168.78.134:9876 group: mail-group bindings: output: destination: mail-group
@EnableBinding(Source.class) public class ProducerService { @Autowired private Source source;
@GetMapping("/mail")
public ResultVo mail(){
source.output().send(MessageBuilder.withPayload("group mail aaaa").build());
return ResultVo.DEFAULT_SUCCESS;
}}
Java is designed as a memory-safe language to prevent common issues like buffer overflows, memory leaks, and the use of uninitialized variables. It achieves this through:
ArrayIndexOutOfBoundsException.Despite being a 'safe, managed runtime', Java provides 'backdoors' for high-performance or low-level access via:
There are several ways to obtain a Class object depending on the available information:
.class literal: The most performant and safest method when the class is known at compile time.getClass(): Used when you have an existing instance of the class.Class.forName(): Used when you only have the fully qualified name of the class as a string. This may throw a ClassNotFoundException..TYPE: Used for primitive data types (e.g., Integer.TYPE).// 1. Class literal
Class<?> c1 = Person.class;
// 2. From instance
Person person = new Person();
Class<?> c2 = person.getClass();
// 3. From fully qualified name
Class<?> c3 = Class.forName("com.liu.User");
// 4. Primitive type
Class<?> c4 = Integer.TYPE;blog/ directory. The filename typically follows a date-based naming convention (e.g., YYYY-MM-DD-title.md).---
slug: greetings
title: Greetings!
authors:
- name: Joel Marcey
title: Co-creator of Docusaurus 1
url: https://github.com/JoelMarcey
image_url: https://github.com/JoelMarcey.png
- name: Sébastien Lorber
title: Docusaurus maintainer
url: https://sebastienlorber.com
image_url: https://github.com/slorber.png
tags: [greetings]
---
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Feel free to play around and edit this post as much you like.rocketmq-spring-boot-starter to integrate RocketMQ into a Spring application. This involves adding the dependency, configuring the NameServer and producer group, and using RocketMQTemplate to send messages.<!-- Dependency -->
<dependency>
<groupId>org.apache.rocketmq</groupId>
<artifactId>rocketmq-spring-boot-starter</artifactId>
<version>2.0.3</version>
</dependency># Configuration
rocketmq:
name-server: 192.168.78.134:9876
producer:
group: test-group@Autowired
private RocketMQTemplate rocketMQTemplate;
@GetMapping("/mq")
public ResultVo mq(){
List<Integer> x = new ArrayList<>();
x.add(1); x.add(2);
Group a = new Group(3, "awd", x);
// Send message to topic "gg"
rocketMQTemplate.convertAndSend("gg", a);
return ResultVo.DEFAULT_SUCCESS;
}getAnnotations() to get all annotations or getAnnotation(Class<A> annotationClass) to retrieve a specific annotation and access its values.Class<?> c = Class.forName("com.liu.Student");
// Get all annotations
Annotation[] annotations = c.getAnnotations();
// Get a specific annotation and its value
Tableliu tableliu = (Tableliu) c.getAnnotation(Tableliu.class);
String value = tableliu.value();