Question

我有一个Maven GWT项目。我将Hibernate和HSQLDB作为持久层包含在内。运行单元测试很好，但是当它尝试运行服务器组件时，日志记录不起作用，所以我对服务器端的错误视而不见。我纠结的错误是：

[错误] log4j：错误A＆＃34; org.apache.log4j.RollingFileAppender＆＃34;对象是不能指定＆＃34; org.apache.log4j.Appender＆＃34;变量。 [错误] log4j：错误类＆＃34; org.apache.log4j.Appender＆＃34;被装载了 [错误] log4j：ERROR [sun.misc.Launcher$AppClassLoader@baf1915] [ERROR] log4j类型的对象：错误＆＃34; org.apache.log4j.RollingFileAppender进行＆＃34;被[WebApp 类加载器= 1312837549 @ 4e404fad]。 [错误] log4j：错误无法实例化名为＆＃34; file＆＃34;的appender。 [错误] log4j：错误A. ＆＃34; org.apache.log4j.ConsoleAppender＆＃34;对象不能分配给a ＆＃34; org.apache.log4j.Appender＆＃34;变量。 [错误] log4j：错误类＆＃34; org.apache.log4j.Appender＆＃34;由[ERROR] log4j加载：ERROR [sun.misc.Launcher$AppClassLoader@baf1915]而类型的对象 [错误] log4j：错误＆＃34; org.apache.log4j.ConsoleAppender＆＃34;被装载了 [WebAppClas sLoader = 1312837549 @ 4e404fad]。 [错误] log4j：错误可以不实例化名为＆＃34; stdout＆＃34;。
的appender

从谷歌搜索我很确定这是因为存在两个log4j.jar实例。有没有一种好方法或最佳实践方法来解决这个问题？我从控制台以开发模式运行项目。我的Pom.xml看起来像这样：

 <?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>testproject</groupId>
 <artifactId>trustme-mdm-gwtp</artifactId>
 <version>1.0-SNAPSHOT</version>
 <packaging>war</packaging>
 <name>GWTP Basic</name>
 <description>Basic GWTP application</description>


 <properties>
 <!-- client -->
 <gwt.version>2.6.0</gwt.version>
 <gwtp.version>1.2.1</gwtp.version>
 <gin.version>2.1.2</gin.version>


 <!-- server -->
 <guice.version>3.0</guice.version>


 <!-- testing -->
 <junit.version>4.7</junit.version>
 <jukito.version>1.4</jukito.version>


 <!-- maven -->
 <gwt-maven-plugin.version>2.6.0</gwt-maven-plugin.version>
 <maven-surefire-plugin.version>2.6</maven-surefire-plugin.version>
 <maven-compiler-plugin.version>2.3.2</maven-compiler-plugin.version>
 <maven-resources-plugin.version>2.5</maven-resources-plugin.version>
 <maven-processor-plugin.version>2.0.5</maven-processor-plugin.version>
 <maven-build-helper-plugin.version>1.7</maven-build-helper-plugin.version>




 <target.jdk>1.7</target.jdk>
 <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
 <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>


 <webappDirectory>${project.build.directory}/${project.build.finalName}</webappDirectory>
 </properties>


 <build>
 <outputDirectory>${webappDirectory}/WEB-INF/classes</outputDirectory>


 <plugins>
 <!-- JUnit Testing - skip *.GwtTest cases -->
 <!-- 'mvn test' - runs the Jukito tests -->
 <plugin>
 <groupId>org.apache.maven.plugins</groupId>
 <artifactId>maven-surefire-plugin</artifactId>
 <version>${maven-surefire-plugin.version}</version>
 <configuration>
 <includes>
 <include>**/*Test.java</include>
 </includes>
 <excludes>
 <exclude>**/*GwtTest.java</exclude>
 </excludes>
 </configuration>
 </plugin>
 <plugin>
 <groupId>org.apache.maven.plugins</groupId>
 <artifactId>maven-compiler-plugin</artifactId>
 <version>2.3.2</version>
 <configuration>
 <source>1.7</source>
 <target>1.7</target>
 </configuration>
 </plugin>


 <!-- GWT -->
 <!-- 'mvn gwt:run' - runs development mode -->
 <!-- 'mvn gwt:debug' - runs debug mode -->
 <!-- 'mvn gwt:compile' - compiles gwt -->
 <!-- 'mvn integration-test' - runs the gwt tests (*GwtTest.java) -->
 <plugin>
 <groupId>org.codehaus.mojo</groupId>
 <artifactId>gwt-maven-plugin</artifactId>
 <version>${gwt.version}</version>
 <configuration>
 <!-- With multiple tests use GwtTestSuite.java for speed -->
 <includes>**/*GwtTest.java</includes>
 <extraJvmArgs>-Xss1024K -Xmx1024M -XX:MaxPermSize=256M</extraJvmArgs>


 <copyWebapp>true</copyWebapp>
 <hostedWebapp>${webappDirectory}</hostedWebapp>


 <runTarget>Project.html</runTarget>
 <modules>
 <module>testproject.Project</module>
 </modules>
 </configuration>
 <executions>
 <execution>
 <goals>
 <goal>compile</goal>
 <goal>test</goal>
 </goals>
 </execution>
 </executions>
 </plugin>
 </plugins>
 </build>


 <dependencies>
 <!-- Google Web Toolkit -->
 <dependency>
 <groupId>com.google.gwt</groupId>
 <artifactId>gwt-user</artifactId>
 <version>${gwt.version}</version>
 </dependency>


 <!-- GWT-Platform -->
 <dependency>
 <groupId>com.gwtplatform</groupId>
 <artifactId>gwtp-all</artifactId>
 <version>${gwtp.version}</version>
 </dependency>


 <!-- DI -->
 <dependency>
 <groupId>com.google.inject</groupId>
 <artifactId>guice</artifactId>
 <version>${guice.version}</version>
 </dependency>
 <dependency>
 <groupId>com.google.inject.extensions</groupId>
 <artifactId>guice-servlet</artifactId>
 <version>${guice.version}</version>
 </dependency>
 <dependency>
 <groupId>com.google.inject.extensions</groupId>
 <artifactId>guice-assistedinject</artifactId>
 <version>${guice.version}</version>
 </dependency>
 <dependency>
 <groupId>com.google.gwt.inject</groupId>
 <artifactId>gin</artifactId>
 <version>${gin.version}</version>
 </dependency>


 <!-- Test -->
 <dependency>
 <groupId>junit</groupId>
 <artifactId>junit</artifactId>
 <version>${junit.version}</version>
 <scope>test</scope>
 </dependency>
 <dependency>
 <groupId>org.jukito</groupId>
 <artifactId>jukito</artifactId>
 <version>${jukito.version}</version>
 <scope>test</scope>
 </dependency>
 <!-- Hibernate -->
 <!-- for JPA, use hibernate-entitymanager instead of hibernate-core -->
 <dependency>
 <groupId>org.hibernate</groupId>
 <artifactId>hibernate-entitymanager</artifactId>
 <version>4.3.5.Final</version>
 </dependency>
 <!-- hSQLDB -->
 <dependency>
 <groupId>org.hsqldb</groupId>
 <artifactId>hsqldb</artifactId>
 <version>2.3.2</version>
 </dependency>
 <!-- add slf4j interfaces to classpath -->
 <dependency>
 <groupId>org.slf4j</groupId>
 <artifactId>slf4j-log4j12</artifactId>
 <version>1.7.7</version>
 </dependency>
 <!--  GWT-Log -->
 <dependency>
 <groupId>com.allen-sauer.gwt.log</groupId>
 <artifactId>gwt-log</artifactId>
 <version>3.3.0</version>
 </dependency>

 </dependencies>
</project>

当我查看\ target ... \ lib文件夹时，这些是部署的jar：

antlr-2.7.7.jar aopalliance-1.0.jar commons-collections-3.2.1.jar commons-lang-2.4.jar commons-logging-1.1.1.jar dom4j-1.6.1.jar gin-2.1.2.jar guava-16.0.1.jar guava-gwt-16.0.1.jar guice-3.0.jar guice-assistedinject-3.0.jar guice-servlet-3.0.jar gwt-jackson-0.4.0.jar gwt-log-3.3.0.jar gwtp-all-1.2.1.jar gwtp-clients-common-1.2.1.jar gwtp-crawler-1.2.1.jar gwtp分派常见的客户端 - 1.2.1.jar gwtp-dispatch-common-shared-1.2.1.jar gwtp-dispatch-rest-1.2.1.jar gwtp-dispatch-rpc-client-1.2.1.jar gwtp-dispatch-rpc-server-1.2.1.jar gwtp分派-RPC服务器 - 吉斯 - 1.2.1.jar gwtp分派-RPC服务器 - 弹簧 - 1.2.1.jar gwtp-dispatch-rpc-shared-1.2.1.jar gwtp-mvp-client-1.2.1.jar gwtp-mvp-shared-1.2.1.jar gwtp-processors-1.2.1.jar gwtp-tester-1.2.1.jar gwt-user-2.6.1.jar 休眠公地的注解，4.0.4.Final.jar hibernate-core-4.3.5.Final.jar hibernate-entitymanager-4.3.5.Final.jar hibernate-jpa-2.1-api-1.0.0.Final.jar hsqldb-2.3.2.jar jackson-annotations-2.3.0.jar jackson-annotations-2.3.0-sources.jar jandex-1.1.0.Final.jar javassist-3.18.1-GA.jar javax.inject-1.jar jboss-logging-3.1.3.GA.jar jboss-logging-annotations-1.2.0.Beta1.jar jboss-transaction-api_1.2_spec-1.0.0.Final.jar json-20090211.jar jsr305-1.3.9.jar jsr311-api-1.1.1.jar maven-artifact-3.1.1.jar plexus-utils-3.0.15.jar servlet-api-2.5.jar spring-aop-3.2.3.RELEASE.jar spring-beans-3.2.3.RELEASE.jar spring-context-3.2.3.RELEASE.jar spring-core-3.2.3.RELEASE.jar spring-expression-3.2.3.RELEASE.jar spring-web-3.2.3.RELEASE.jar validation-api-1.0.0.GA.jar validation-api-1.0.0.GA-sources.jar velocity-1.7.jar xml-apis-1.0.b2.jar

我将pom.xml更改为：

<!-- Google Web Toolkit -->
<dependency>
    <groupId>com.google.gwt</groupId>
    <artifactId>gwt-servlet</artifactId>
    <version>${gwt.version}</version>
    <scope>runtime</scope>
</dependency>
<dependency>
    <groupId>com.google.gwt</groupId>
    <artifactId>gwt-user</artifactId>
    <version>${gwt.version}</version>
    <scope>provided</scope>
</dependency>

但仍然没有成功......

我插入了依赖树的屏幕截图。我的声誉不允许粘贴图片。它存储在这里：

Answer 1

感谢您的帮助（特别是托马斯）。我用于我的项目的指南声明log4j和slf4j在pom.xml中作为外部引用是必要的我只是删除它，它现在正在工作。然而，这告诉我，通过不结合服务器和客户端依赖关系，它确实使生活变得更简单。

Answer 2

将log4j依赖范围更改为maven.check中提供的是否有多个记录器jar。

Answer 3

您可能面临GWT 2.6.0的已知问题，该问题错误地在DevMode中加载服务器端类：https://code.google.com/p/google-web-toolkit/issues/detail?id=8585

尝试使用GWT 2.6.1，看看是否能解决问题。

编辑另外，清理依赖项的范围：gwt-user中有servlet-api和WEB-INF/lib，但不得在那里;你也有一堆特定于GWT的客户端JAR，它们也不应该存在。

maven和gwt：org.apache.log4j.XAppender对象的Log4j问题不可分配

3 个答案: