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SpringBoot利用dag加速Spring beans初始化的方法示例

更新時間：2024年12月27日 10:56:27 作者：HBLOG

本文介紹了利用DAG加速SpringBoot中Spring beans初始化,先解釋了DAG 概念及特性,包括節(jié)點入度出度、拓撲排序等,接著闡述加速Spring Bean初始化的實現思路,如識別依賴關系構建DAG、拓撲排序、并行初始化Bean及與Spring集成,還展示了相關代碼工程、測試結果及引用

1.什么是Dag？

有向無環(huán)圖(Directed Acyclic Graph)，簡稱DAG，是一種有向圖，其中沒有從節(jié)點出發(fā)經過若干條邊后再回到該節(jié)點的路徑。換句話說，DAG中不存在環(huán)路。這種數據結構常用于表示并解決具有依賴關系的問題。

DAG的特性

首先，DAG中的節(jié)點可以有入度和出度。節(jié)點的入度是指指向該節(jié)點的邊的數量，而節(jié)點的出度是指由該節(jié)點指向其他節(jié)點的邊的數量。在DAG中，節(jié)點的入度可以是0或正整數，而出度可以是0或正整數，但不能同時為負數。
DAG的另一個重要性質是存在一個或多個拓撲排序。拓撲排序是DAG中節(jié)點的線性排列，滿足任意一條有向邊的起點在排序中都位于終點之前?？梢允褂蒙疃葍?yōu)先搜索(DFS)或寬度優(yōu)先搜索(BFS)算法來生成拓撲排序。

DAG的應用

任務調度
編譯器優(yōu)化
數據流分析
電路設計

2.如何加速Spring Bean初始化？

在Spring框架中進行DAG（有向無環(huán)圖）分析以實現并行初始化，可以有效提升應用程序啟動的性能。通常情況下，Spring應用程序的Bean是按依賴順序初始化的，而通過DAG分析可以識別出哪些Bean之間沒有依賴關系，并行初始化這些Bean可以減少啟動時間。以下是實現思路：

1. 識別依賴關系，構建DAG

首先需要識別Spring Bean之間的依賴關系。可以通過@DependsOn注解、構造器注入或@Autowired等方式獲取Bean依賴。具體步驟：

遍歷Spring上下文中的所有Bean定義。
根據Bean的依賴關系構建DAG，節(jié)點代表Bean，邊表示依賴關系。

Spring的ApplicationContext提供了getBeanDefinitionNames()方法可以列出所有的Bean，通過BeanDefinition可以分析出依賴。

2. 拓撲排序

通過拓撲排序（Topological Sorting）對DAG進行排序，以確保Bean按依賴順序初始化。拓撲排序可以確定哪些Bean可以并行初始化，哪些Bean必須在某些Bean之后初始化。使用算法如Kahn’s Algorithm或DFS找到所有沒有依賴的Bean（入度為0的節(jié)點），這些節(jié)點可以并行初始化。

3. 并行初始化Bean

在完成拓撲排序后，使用多線程來并行初始化可以同時啟動的Bean?？梢允褂肑ava的ExecutorService或類似的線程池機制來管理并發(fā)的Bean初始化過程。 步驟：

針對所有入度為0的節(jié)點，啟動一個線程來初始化它們。
當某個Bean初始化完成后，減少它所依賴的其他Bean的入度值。
當某個Bean的入度為0時，可以在另一個線程中啟動它的初始化。

4. Spring Integration

可以通過BeanFactoryPostProcessor或ApplicationContextInitializer來掛鉤到Spring的初始化流程中，分析Bean之間的依賴關系，并將并行化初始化邏輯集成到Spring容器的啟動過程中。具體方法：

實現BeanFactoryPostProcessor，在Bean初始化之前分析Bean的依賴并構建DAG。
在Bean初始化階段，使用多線程并行處理獨立的Bean。

3.代碼工程

整體的依賴關系如下：

實驗目標

實現自定義Bean并行化加載

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>3.2.1</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>dag</artifactId>

    <properties>
        <maven.compiler.source>17</maven.compiler.source>
        <maven.compiler.target>17</maven.compiler.target>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-autoconfigure</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.jgrapht</groupId>
            <artifactId>jgrapht-core</artifactId>
            <version>1.5.1</version>
        </dependency>

    </dependencies>
    <build>
        <pluginManagement>
            <plugins>
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-compiler-plugin</artifactId>
                    <version>3.8.1</version>
                    <configuration>
                        <fork>true</fork>
                        <failOnError>false</failOnError>
                    </configuration>
                </plugin>

                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-surefire-plugin</artifactId>
                    <version>2.22.2</version>
                    <configuration>
                        <forkCount>0</forkCount>
                        <failIfNoTests>false</failIfNoTests>
                    </configuration>
                </plugin>
            </plugins>
        </pluginManagement>
    </build>
</project>

Bean初始化

package com.et.config;

import org.jgrapht.graph.DefaultEdge;
import org.jgrapht.graph.DirectedAcyclicGraph;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.beans.factory.config.BeanFactoryPostProcessor;
import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
import org.springframework.stereotype.Component;

import java.util.*;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.stream.Collectors;

@Component
public class DAGBeanInitializer implements BeanFactoryPostProcessor {

    private final ExecutorService executorService = Executors.newFixedThreadPool(10);

    @Override
    public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) throws BeansException {
        Map<String, BeanDefinition> beanDefinitionMap = new HashMap<>();
        for (String beanName : beanFactory.getBeanDefinitionNames()) {
            BeanDefinition beanDefinition = beanFactory.getBeanDefinition(beanName);
            beanDefinitionMap.put(beanName, beanDefinition);
        }

        // build DAG
        DirectedAcyclicGraph<String, DefaultEdge> dag = buildDAG(beanDefinitionMap,beanFactory);

        // bean layers
        List<Set<String>> layers = getBeansByLayer(dag);
        System.out.println("layers:"+layers);
        // init bean by layers
        initializeBeansInLayers(layers, beanFactory);
    }

    // DAG Bean
    private DirectedAcyclicGraph<String, DefaultEdge> buildDAG(Map<String, BeanDefinition> beanDefinitionMap, ConfigurableListableBeanFactory beanFactory) {
        DependencyResolver resolver = new DependencyResolver(beanFactory);
        DirectedAcyclicGraph<String, DefaultEdge> dag = new DirectedAcyclicGraph<>(DefaultEdge.class);
        for (String beanName : beanDefinitionMap.keySet()) {
            if(shouldLoadBean(beanName)) {
                dag.addVertex(beanName);
                String[] dependencies = beanDefinitionMap.get(beanName).getDependsOn();
                if (dependencies != null) {
                    for (String dependency : dependencies) {
                        dag.addEdge(dependency, beanName); 
                    }
                }
                // get @Autowired dependencies
                Set<String> autowireDependencies = resolver.getAllDependencies(beanName);
                for (String autowireDependency : autowireDependencies) {
                    // convert beanName
                    String autowireBeanName = convertToBeanName(autowireDependency);
                    dag.addVertex(autowireBeanName);
                    dag.addEdge(autowireBeanName, beanName);
                }
            }
        }
        return dag;
    }
    private String convertToBeanName(String className) {
        String simpleName = className.substring(className.lastIndexOf('.') + 1);
        return Character.toLowerCase(simpleName.charAt(0)) + simpleName.substring(1);
    }
    private List<Set<String>> getBeansByLayer(DirectedAcyclicGraph<String,DefaultEdge> dag) {
        List<Set<String>> layers = new ArrayList<>();
        Map<String, Integer> inDegree = new HashMap<>();
        Queue<String> queue = new LinkedList<>();

        // init all nodes degree
        for (String vertex : dag) {
            int degree = dag.inDegreeOf(vertex);
            inDegree.put(vertex, degree);
            if (degree == 0) {
                queue.offer(vertex);  //zero degree as the first layer
            }
        }

        // BFS process everyLayers
        while (!queue.isEmpty()) {
            Set<String> currentLayer = new HashSet<>();
            int size = queue.size();
            for (int i = 0; i < size; i++) {
                String currentBean = queue.poll();
                currentLayer.add(currentBean);

                // iterator layers
                for (String successor : getSuccessors(dag,currentBean)) {
                    inDegree.put(successor, inDegree.get(successor) - 1);
                    if (inDegree.get(successor) == 0) {
                        queue.offer(successor);  // add next layer when the degress is zero
                    }
                }
            }
            layers.add(currentLayer);
        }

        return layers;
    }
    // get next node
    private Set<String> getSuccessors(DirectedAcyclicGraph<String, DefaultEdge> dag, String vertex) {
        // get outgoingEdges
        Set<DefaultEdge> outgoingEdges = dag.outgoingEdgesOf(vertex);

        // find the next node
        return outgoingEdges.stream()
                .map(edge -> dag.getEdgeTarget(edge))
                .collect(Collectors.toSet());
    }
    // init beans by layer
    private void initializeBeansInLayers(List<Set<String>> layers, ConfigurableListableBeanFactory beanFactory) {
        for (Set<String> layer : layers) {
            // Beans of the same layer can be initialized in parallel
            List<CompletableFuture<Void>> futures = new ArrayList<>();
            for (String beanName : layer) {
                // only load beans that  wrote by yourself
                if (shouldLoadBean(beanName)) {
                    CompletableFuture<Void> future = CompletableFuture.runAsync(() -> {
                        try {
                            beanFactory.getBean(beanName);  // init Bean
                        } catch (Exception e) {
                            System.err.println("Failed to initialize bean: " + beanName);
                            e.printStackTrace();
                        }
                    }, executorService);
                    futures.add(future);
                }
            }
            //Wait for all beans in the current layer to be initialized before initializing the next layer.
            CompletableFuture<Void> allOf = CompletableFuture.allOf(futures.toArray(new CompletableFuture[0]));
            allOf.join();  // make sure to be done on current layer
        }
    }

    private boolean shouldLoadBean(String beanName) {
        return beanName.startsWith("helloWorldController")
                ||beanName.startsWith("serviceOne")
                ||beanName.startsWith("serviceTwo")
                ||beanName.startsWith("serviceThree");
    }
}

獲取bean@Autowired依賴

package com.et.config;

import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import java.lang.reflect.Field;
import java.util.HashSet;
import java.util.Set;

@Component
public class DependencyResolver {

    private final ConfigurableListableBeanFactory beanFactory;

    @Autowired
    public DependencyResolver(ConfigurableListableBeanFactory beanFactory) {
        this.beanFactory = beanFactory;
    }

    public Set<String> getAllDependencies(String beanName) {
        Set<String> dependencies = new HashSet<>();

        // get Bean definite
        BeanDefinition beanDefinition = beanFactory.getBeanDefinition(beanName);

        // reflect
        try {
            Class<?> beanClass = Class.forName(beanDefinition.getBeanClassName());
            Field[] fields = beanClass.getDeclaredFields();
            for (Field field : fields) {
                if (field.isAnnotationPresent(Autowired.class)) {
                    dependencies.add(field.getType().getName()); 
                }
            }
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }

        return dependencies;
    }
}

controller

package com.et.controller;

import com.et.service.ServiceTwo;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import com.et.service.*;
import java.util.HashMap;
import java.util.Map;

@RestController
public class HelloWorldController {
    @Autowired
    ServiceOne ServiceOne;
    @Autowired
    ServiceTwo ServiceTwo;
    @RequestMapping("/hello")
    public Map<String, Object> showHelloWorld(){
        Map<String, Object> map = new HashMap<>();
        map.put("msg", "HelloWorld");
        return map;
    }
}

service

package com.et.service;

import org.springframework.stereotype.Service;

/**
 * @author liuhaihua
 * @version 1.0
 * @ClassName ServiceOne
 * @Description todo
 * @date 2024/09/20/ 14:01
 */
@Service
public class ServiceOne {
    private   void  sayhi(){
        System.out.println("this is service one sayhi");
    }
}

package com.et.service;

import org.springframework.stereotype.Service;

/**
 * @author liuhaihua
 * @version 1.0
 * @ClassName ServiceOne
 * @Description todo
 * @date 2024/09/20/ 14:01
 */
@Service
public class ServiceThree {

    private   void  sayhi(){
        System.out.println("this is service three sayhi");
    }
}

package com.et.service;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

/**
 * @author liuhaihua
 * @version 1.0
 * @ClassName ServiceOne
 * @Description todo
 * @date 2024/09/20/ 14:01
 */
@Service
public class ServiceTwo {
    @Autowired
    ServiceThree serviceThree;
    private   void  sayhi(){
        System.out.println("this is service two sayhi");
    }
}

只是一些關鍵代碼

4.測試

啟動Spring Boot工程，查看bean加載順序如下

2024-09-20T15:51:27.081+08:00 INFO 33188 --- [ main] com.et.DemoApplication : Starting DemoApplication using Java 17.0.9 with PID 33188 (D:\IdeaProjects\ETFramework\dag\target\classes started by Dell in D:\IdeaProjects\ETFramework)
2024-09-20T15:51:27.085+08:00 INFO 33188 --- [ main] com.et.DemoApplication : No active profile set, falling back to 1 default profile: "default"
layers:[[serviceOne, serviceThree], [serviceTwo], [helloWorldController]]
2024-09-20T15:51:28.286+08:00 INFO 33188 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port 8088 (http)
2024-09-20T15:51:28.297+08:00 INFO 33188 --- [ main] o.apache.catalina.core.StandardService : Starting service [Tomcat]
2024-09-20T15:51:28.297+08:00 INFO 33188 --- [ main] o.apache.catalina.core.StandardEngine : Starting Servlet engine: [Apache Tomcat/10.1.17]
2024-09-20T15:51:28.373+08:00 INFO 33188 --- [ main] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext
2024-09-20T15:51:28.374+08:00 INFO 33188 --- [ main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 1198 ms
2024-09-20T15:51:28.725+08:00 INFO 33188 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port 8088 (http) with context path ''
2024-09-20T15:51:28.732+08:00 INFO 33188 --- [ main] com.et.DemoApplication

以上就是SpringBoot利用dag加速Spring beans初始化的方法示例的詳細內容，更多關于SpringBoot dag加速beans初始化的資料請關注腳本之家其它相關文章！

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SpringBoot利用dag加速Spring beans初始化的方法示例

目錄

1.什么是Dag？

DAG的特性

DAG的應用

2.如何加速Spring Bean初始化？

1. 識別依賴關系，構建DAG

2. 拓撲排序

3. 并行初始化Bean

4. Spring Integration

3.代碼工程

實驗目標

pom.xml

controller

service

4.測試

相關文章

最新評論

大家感興趣的內容

最近更新的內容

常用在線小工具

亚洲乱码中文字幕综合,中国熟女仑乱hd,亚洲精品乱拍国产一区二区三区,一本大道卡一卡二卡三乱码全集资源,又粗又黄又硬又爽的免费视频

SpringBoot利用dag加速Spring beans初始化的方法示例

目錄

1.什么是Dag？

DAG的特性

DAG的應用

2.如何加速Spring Bean初始化？

1. 識別依賴關系，構建DAG

2. 拓撲排序

3. 并行初始化Bean

4. Spring Integration

3.代碼工程

實驗目標

pom.xml

controller

service

4.測試

相關文章

最新評論

大家感興趣的內容

最近更新的內容

常用在線小工具

1.什么是Dag？

2.如何加速Spring Bean初始化？