在IntelliJ中使用Weld SE和CDI时容器初始化失败求助

问题场景 #

在IntelliJ Ultimate版中创建基于Weld SE和CDI的基础项目：选择Jakarta EE Web Application模板，采用Maven构建，添加CDI与Weld SE依赖，使用JDK 17。

项目代码 #

public interface Pet {
}

public class Dog implements Pet {
}

public class Person {
    Pet itsPet;

    @Inject
    public Person(Pet pet){
        itsPet = pet;
    }
}

import org.jboss.weld.environment.se.Weld;
import org.jboss.weld.environment.se.WeldContainer;

public class MainApp {
    public static void main(String[] args) {
        WeldContainer container = new Weld().initialize();
        Person person = container.select(Person.class).get();
    }
}

启动错误 #

Mar 17, 2023 8:21:41 AM org.jboss.weld.bootstrap.WeldStartup <clinit>
INFO: WELD-000900: 4.0.3 (Final)
Mar 17, 2023 8:21:41 AM org.jboss.weld.environment.deployment.discovery.ReflectionDiscoveryStrategy processAnnotatedDiscovery
INFO: WELD-ENV-000014: Falling back to Java Reflection for bean-discovery-mode="annotated" discovery. Add org.jboss:jandex to the classpath to speed-up startup.
Exception in thread "main" java.lang.IllegalStateException: WELD-ENV-002009: Weld SE container cannot be initialized - no bean archives found
at org.jboss.weld.environment.se.Weld.createDeployment(Weld.java:995)
at org.jboss.weld.environment.se.Weld.initialize(Weld.java:787)
at student.MainApp.main(MainApp.java:8)

pom.xml配置 #

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">

    <modelVersion>4.0.0</modelVersion>

    <groupId>com.example</groupId>
    <artifactId>try</artifactId>
    <version>1.0-SNAPSHOT</version>
    <name>try</name>
    <packaging>war</packaging>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.target>11</maven.compiler.target>
        <maven.compiler.source>11</maven.compiler.source>
        <junit.version>5.9.1</junit.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>jakarta.servlet</groupId>
            <artifactId>jakarta.servlet-api</artifactId>
            <version>5.0.0</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.jboss.weld.se</groupId>
            <artifactId>weld-se-core</artifactId>
            <version>4.0.3.Final</version>
        </dependency>
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-api</artifactId>
            <version>${junit.version}</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-engine</artifactId>
            <version>${junit.version}</version>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-war-plugin</artifactId>
                <version>3.3.2</version>
            </plugin>
        </plugins>
    </build>
</project>

beans.xml位置与内容 #

位于target/classes/META-INF/下：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="https://jakarta.ee/xml/ns/jakartaee"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="https://jakarta.ee/xml/ns/jakartaee https://jakarta.ee/xml/ns/jakartaee/beans_3_0.xsd"
       bean-discovery-mode="annotated">

</beans>

解决方案 #

1. 修正Maven打包格式 #

Weld SE是Java SE环境，当前war打包方式适配Web应用，改为jar：

<packaging>jar</packaging>

同时替换maven-war-plugin为maven-jar-plugin（可选，更贴合SE环境）：

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-jar-plugin</artifactId>
    <version>3.3.0</version>
    <configuration>
        <archive>
            <manifest>
                <mainClass>student.MainApp</mainClass> <!-- 指定主类 -->
            </manifest>
        </archive>
    </configuration>
</plugin>

2. 统一JDK版本配置 #

pom中source/target为11，实际使用JDK17，同步版本：

<properties>
    <!-- 其他属性保留 -->
    <maven.compiler.target>17</maven.compiler.target>
    <maven.compiler.source>17</maven.compiler.source>
</properties>

3. 调整Bean发现策略 #

当前bean-discovery-mode="annotated"要求类必须带有CDI注解才会被识别为bean，有两种解决方式：

方式一：给类添加CDI注解

给Dog和Person添加@Named注解（或其他CDI作用域注解如@ApplicationScoped）：

import jakarta.inject.Named;

@Named
public class Dog implements Pet {
}

@Named
public class Person {
    Pet itsPet;

    @Inject
    public Person(Pet pet){
        itsPet = pet;
    }
}

方式二：修改beans.xml的发现模式

将bean-discovery-mode改为all，扫描所有类作为候选bean：

<bean-discovery-mode="all">

4. 确保beans.xml在源码目录 #

将beans.xml从target/classes/META-INF/复制到src/main/resources/META-INF/，这样Maven编译时会自动将其复制到target目录，保证运行时能被Weld识别。

内容的提问来源于stack exchange，提问作者Shaharg