为什么我的 Java 应用程序在本地运行但在交付到 IBM Cloud 时出现此错误

Question

我创建了一个应用程序，它使用 JPA 以及带有 JAX-RS 的 servlet。

当我在本地运行应用程序时，我能够使用 curl 查询我的服务器并获得所有 GET 和 POST 请求的正确响应。但是，当我在 IBM Cloud 上托管服务器并使用 curl 对其进行查询时，出现错误："No Persistence provider for EntityManager".

是什么导致了本地和远程 (IBM Cloud) 环境之间的差异，我该如何解决？

persistence.xml

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.1" xmlns="http://xmlns.jcp.org/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd">
    <persistence-unit name="ibmcloud">
    <provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>
    <non-jta-data-source>java:comp/DefaultDataSource</non-jta-data-source>
        <class>entities.Comment</class>
        <properties>
            <property name="javax.persistence.schema-generation.database.action" value="drop-and-create"/>
            <property name="hibernate.show_sql" value="true"/>
            <property name="hibernate.format_sql" value="true"/>
            <property name="hibernate.use_sql_comments" value="true"/>

        </properties>
    </persistence-unit>
</persistence>

.travis.yml

language: java
jdk: oraclejdk8
sudo: false
before_install:
   mvn install -DskipTests=true -Dmaven.javadoc.skip=true -B -V
before_deply:
   cf login -u $BLUEMIX_USER -o $BLUEMIX_ORG
script:
   mvn test -B
language: java
git:
  depth: 1
dist: trusty
cache:
  directories:
  - "$HOME/.m2"
deploy:
  edge: true
  provider: bluemixcloudfoundry
  username: $BLUEMIX_USER
  password: $BLUEMIX_PASSWORD
  organization: $BLUEMIX_ORG
  space: $BLUEMIX_SPACE
  manifest: manifest.yml
  app_name: ibmcloudapp
  region: eu-gb
  api: https://api.eu-gb.bluemix.net
  skip_cleanup: true

manifest.yml

applications:
 - name: ibmcloud
   path: target/ibmcloud.war
   instances: 1
   random-route: true

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">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.dotheminimum</groupId>
    <artifactId>ibmcloud</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>war</packaging>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
        <failOnMissingWebXml>false</failOnMissingWebXml>
    </properties>

    <dependencies>
        <!-- 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.junit.jupiter</groupId>
        <artifactId>junit-jupiter-api</artifactId>
        <version>5.4.0</version>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>org.junit.jupiter</groupId>
        <artifactId>junit-jupiter-engine</artifactId>
        <version>5.4.0</version>
        <scope>test</scope>
    </dependency>
        <!-- https://mvnrepository.com/artifact/org.hibernate.javax.persistence/hibernate-jpa-2.1-api -->
<!-- <dependency>
    <groupId>org.hibernate.javax.persistence</groupId>
    <artifactId>hibernate-jpa-2.1-api</artifactId>
    <version>1.0.2.Final</version>
</dependency> -->
<!-- https://mvnrepository.com/artifact/javax.persistence/javax.persistence-api -->
<dependency>
    <groupId>javax.persistence</groupId>
    <artifactId>javax.persistence-api</artifactId>
    <version>2.2</version>
</dependency>       
    </dependencies>
    <build>
        <finalName>${project.artifactId}</finalName>
        <plugins>
            <plugin>
                <artifactId>maven-surefire-plugin</artifactId>
                <version>2.22.1</version>
            </plugin>
        </plugins>
    </build>
</project>

应用程序的源代码已托管 here

Answer 1

问题是我的 "persistence.xml" 文件在 "src/main/java/META-INF" 而不是 "src/main/resources/META-INF"。

我的本地环境能够找到该文件，但 IBM Cloud 找不到。更改 "persistence.xml" 的路径后，IBM Cloud 检测到该文件。

如果我已经详尽无遗，我将能够在 Billy Frost (No Persistence provider for EntityManager named)

链接的搜索的第一个结果的评论中找到我的解决方案

为什么我的 Java 应用程序在本地运行但在交付到 IBM Cloud 时出现此错误

Why does my Java app work in local but when delivering to IBM Cloud it gives this error

java

jpa

persistence.xml

ibm-cloud