Question

我正在尝试使用RX-JS项目创建一个简单的项目，该项目通过DI使用某些类。但是，我收到了NullPointer异常，这意味着DI无法正常工作。

然后在src / main / java / webservice / Services.java中

@Path("/")
public class Services {

        @Inject
        private ConfigFileEntity cfe;
        @GET
        @Path("/books")
        @Produces(MediaType.APPLICATION_JSON)
        public Response getBooks(){
            cfe.readFile();
            return Response.ok().build();

        }
}

以及src / main / java / webservice / ConfigFileEntity.java

@Singleton
@LocalBean
public class ConfigFileEntity {

    private Properties readFile() throws Exception {
        Properties prop = new Properties();
        try{

            FileInputStream is = new FileInputStream("A path");
            prop.load(is);

            return prop;

        }catch (Exception e){
            throw new Exception(e.getMessage());
        }
    }
}

我也有src / main / resources / META-INF / beans.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans
    xmlns="http://xmlns.jcp.org/xml/ns/javaee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee 
                      http://xmlns.jcp.org/xml/ns/javaee/beans_1_1.xsd"
    bean-discovery-mode="all">
</beans>

我在inject gives a nullpointer exception中提出了类似的问题，但是我将机器（Linux更改为Windows）和Application Server（JBoss更改为Glassfish）。所以我不确定自己做错了什么。

我的项目的结构是：

而pom.xml是：

<?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">
  <modelVersion>4.0.0</modelVersion>

  <groupId>webservice</groupId>
  <artifactId>webservice</artifactId>
  <version>1.0-SNAPSHOT</version>

  <name>webservice</name>
  <!-- FIXME change it to the project's website -->
  <url>http://www.example.com</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <maven.compiler.source>1.7</maven.compiler.source>
    <maven.compiler.target>1.7</maven.compiler.target>
  </properties>

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.11</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>org.json</groupId>
      <artifactId>json</artifactId>
      <version>20180813</version>
    </dependency>
    <dependency>
      <groupId>javax</groupId>
      <artifactId>javaee-api</artifactId>
      <version>7.0</version>
      <scope>provided</scope>
    </dependency>
    <!-- https://mvnrepository.com/artifact/javax.ws.rs/javax.ws.rs-api -->
    <dependency>
      <groupId>javax.ws.rs</groupId>
      <artifactId>javax.ws.rs-api</artifactId>
      <version>2.1.1</version>
    </dependency>
    <dependency>
      <groupId>org.bitbucket.b_c</groupId>
      <artifactId>jose4j</artifactId>
      <version>0.6.5</version>
    </dependency>
    <dependency>
      <groupId>log4j</groupId>
      <artifactId>log4j</artifactId>
      <version>1.2.17</version>
    </dependency>

  </dependencies>

  <build>
    <resources>
      <resource>
        <directory>src/main/resources</directory>
        <includes>
          <include>**/*.properties</include>
        </includes>
      </resource>
    </resources>
    <pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) -->
      <plugins>
        <!-- clean lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#clean_Lifecycle -->
        <plugin>
          <artifactId>maven-clean-plugin</artifactId>
          <version>3.1.0</version>
        </plugin>
        <!-- default lifecycle, jar packaging: see https://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_jar_packaging -->
        <plugin>
          <artifactId>maven-resources-plugin</artifactId>
          <version>3.0.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-compiler-plugin</artifactId>
          <version>3.8.0</version>
        </plugin>
        <plugin>
          <artifactId>maven-surefire-plugin</artifactId>
          <version>2.22.1</version>
        </plugin>
        <plugin>
          <artifactId>maven-jar-plugin</artifactId>
          <version>3.0.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-install-plugin</artifactId>
          <version>2.5.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-deploy-plugin</artifactId>
          <version>2.8.2</version>
        </plugin>
        <!-- site lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#site_Lifecycle -->
        <plugin>
          <artifactId>maven-site-plugin</artifactId>
          <version>3.7.1</version>
        </plugin>
        <plugin>
          <artifactId>maven-project-info-reports-plugin</artifactId>
          <version>3.0.0</version>
        </plugin>
      </plugins>
    </pluginManagement>
  </build>
</project>

谢谢

Answer 1

您需要使用一些注释来注释您的服务类，以使其可以被容器发现。如果它是服务类，我建议使用@Service批注，然后重试。

使用Intellij在Java中使用依赖注入创建一个简单的应用程序

1 个答案: