Question

所以我正在尝试用JDO编写一个GAE应用程序。问题是即使看起来我已经在我的pom.xml中已经拥有了所有必需的依赖项，当我在IDE中搜索com.google.appengine.datanucleus.DatastoreManager时，我实际上可以找到它，我的应用程序抛出异常启动

org.datanucleus.exceptions.ClassNotResolvedException：Class 找不到“com.google.appengine.datanucleus.DatastoreManager” CLASSPATH。请检查您的规格和CLASSPATH。

这是我的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>
        <artifactId>livefun</artifactId>
        <groupId>fi.livefun</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <properties>
        <appengine.app.version>1</appengine.app.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <groupId>fi.livefun</groupId>
    <artifactId>livefun-web</artifactId>
    <packaging>war</packaging>

    <dependencies>

        <!-- **********************************************************************
           ** MODULE DEPENDENCIES
       ** ********************************************************************** -->


        <!-- **********************************************************************
           ** GOOGLE APP ENGINE DEPENDIENCIES
       ** ********************************************************************** -->

        <dependency>
            <groupId>com.google.appengine</groupId>
            <artifactId>appengine-api-1.0-sdk</artifactId>
            <version>1.9.12</version>
        </dependency>

        <dependency>
            <groupId>com.google.appengine</groupId>
            <artifactId>appengine-endpoints</artifactId>
            <version>1.9.12</version>
        </dependency>

        <dependency>
            <groupId>javax</groupId>
            <artifactId>javaee-api</artifactId>
            <version>7.0</version>
            <scope>provided</scope>
        </dependency>

        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>jstl</artifactId>
            <version>1.2</version>
        </dependency>

        <dependency>
            <groupId>javax.ws.rs</groupId>
            <artifactId>jsr311-api</artifactId>
            <version>1.1.1</version>
        </dependency>

        <dependency>
            <groupId>com.google.guava</groupId>
            <artifactId>guava</artifactId>
            <version>18.0</version>
        </dependency>

        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.1.0</version>
        </dependency>

        <!-- **********************************************************************
             **                 SPRING DEPENDENCIES                              **
             ********************************************************************** -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-orm</artifactId>
            <version>${spring.framework.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-tx</artifactId>
            <version>${spring.framework.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>${spring.framework.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-web</artifactId>
            <version>${spring.framework.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>${spring.framework.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>${spring.framework.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context-support</artifactId>
            <version>${spring.framework.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.security</groupId>
            <artifactId>spring-security-core</artifactId>
            <version>${spring.security.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.security</groupId>
            <artifactId>spring-security-web</artifactId>
            <version>${spring.security.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.security</groupId>
            <artifactId>spring-security-config</artifactId>
            <version>${spring.security.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.security</groupId>
            <artifactId>spring-security-taglibs</artifactId>
            <version>${spring.security.version}</version>
        </dependency>

        <!-- **********************************************************************
             **                 PERSISTENCE DEPENDENCIES                             **
             ********************************************************************** -->
        <dependency>
            <groupId>org.datanucleus</groupId>
            <artifactId>datanucleus-core</artifactId>
            <version>4.0.4</version>
        </dependency>

        <dependency>
            <groupId>org.datanucleus</groupId>
            <artifactId>datanucleus-api-jdo</artifactId>
            <version>4.0.4</version>
        </dependency>

        <dependency>
            <groupId>javax.jdo</groupId>
            <artifactId>jdo-api</artifactId>
            <version>3.0.1</version>
        </dependency>

        <dependency>
            <groupId>com.google.appengine.orm</groupId>
            <artifactId>datanucleus-appengine</artifactId>
            <version>2.1.2</version>
        </dependency>

        <!-- **********************************************************************
             **                 GENERAL DEPENDENCIES                             **
             ********************************************************************** -->
        <dependency>
            <groupId>taglibs</groupId>
            <artifactId>standard</artifactId>
            <version>1.1.2</version>
        </dependency>
        <dependency>
            <groupId>javax.servlet.jsp</groupId>
            <artifactId>jsp-api</artifactId>
            <version>2.1</version>
            <scope>provided</scope>
        </dependency>

        <!-- **********************************************************************
             **                 OTHER DEPENDENCIES                               **
             ********************************************************************** -->
        <dependency>
            <groupId>org.hsqldb</groupId>
            <artifactId>hsqldb</artifactId>
            <version>${hsqldb.version}</version>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.14</version>
        </dependency>
        <dependency>
            <groupId>commons-lang</groupId>
            <artifactId>commons-lang</artifactId>
            <version>2.6</version>
        </dependency>

        <!-- **********************************************************************
            ** TEST DEPENDENCIES
        ** ********************************************************************** -->

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>${spring.framework.version}</version>
        </dependency>

    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.zeroturnaround</groupId>
                <artifactId>jrebel-maven-plugin</artifactId>
                <version>1.1.5</version>
                <configuration>
                    <addResourcesDirToRebelXml>true</addResourcesDirToRebelXml>
                    <alwaysGenerate>true</alwaysGenerate>
                    <showGenerated>true</showGenerated>
                    <webappDirectory>src/main/webapp/</webappDirectory>
                </configuration>
                <executions>
                    <execution>
                        <id>generate-rebel-xml</id>
                        <phase>process-resources</phase>
                        <goals>
                            <goal>generate</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>

            <plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>versions-maven-plugin</artifactId>
                <version>2.1</version>
                <executions>
                    <execution>
                        <phase>compile</phase>
                        <goals>
                            <goal>display-dependency-updates</goal>
                            <goal>display-plugin-updates</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>

            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-war-plugin</artifactId>
                <version>2.4</version>
                <configuration>
                    <archiveClasses>true</archiveClasses>
                    <webResources>
                        <!-- in order to interpolate version from pom into appengine-web.xml -->
                        <resource>
                            <directory>${basedir}/src/main/webapp/WEB-INF</directory>
                            <filtering>true</filtering>
                            <targetPath>WEB-INF</targetPath>
                        </resource>
                    </webResources>
                </configuration>
            </plugin>

            <plugin>
                <groupId>com.google.appengine</groupId>
                <artifactId>appengine-maven-plugin</artifactId>
                <version>1.9.12</version>
                <configuration>
                    <enableJarClasses>false</enableJarClasses>
                    <!-- Comment in the below snippet to bind to all IPs instead of just localhost -->
                    <!-- address>0.0.0.0</address>
                    <port>8080</port -->
                    <!-- Comment in the below snippet to enable local debugging with a remove debugger
                         like those included with Eclipse or IntelliJ -->
                    <!-- jvmFlags>
                      <jvmFlag>-agentlib:jdwp=transport=dt_socket,address=8000,server=y,suspend=n</jvmFlag>
                    </jvmFlags -->
                </configuration>
            </plugin>

            <plugin>
                <groupId>org.datanucleus</groupId>
                <artifactId>maven-datanucleus-plugin</artifactId>
                <version>3.1.2</version>
                <configuration>
                    <fork>false</fork>
                    <verbose>true</verbose>
                </configuration>
                <executions>
                    <execution>
                        <phase>process-classes</phase>
                        <goals>
                            <goal>enhance</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>

        </plugins>
    </build>

</project>

Answer 1

如果在将应用程序部署到App Engine时看到此错误，则表示您未在WEB-INF/lib文件夹中包含所需的jar。它还不足以在你的类路径上使用它 - 你还需要将它提供给在App Engine上运行的应用程序。

如果您使用Eclipse，请选择您的项目并查看“问题”选项卡。可能存在警告，表明服务器上没有资源。右键单击它并选择＆＃34;复制...＆＃34;选项。或者找到这个jar并手动将其复制到该文件夹。

找不到DatastoreManager，即使它是依赖项之一

1 个答案: