java.lang.NoClassDefFoundError：com / google / gson / Gson

问题是当我将符号系统工件推送到存储库时，它不会将pom推入存储库。所以当我使用符号系统工件作为依赖项时，我的项目无法知道什么是传递依赖关系。

所以我把我的pom和jar一起推入存储库，现在它能够获得所有的依赖。

I noticed a strange problem. I am able to run my test cases using Junit but when I am running using maven One of the test case is failing. It is complaining that Gson class def is not found.

I am able to see the Gson jar in Maven dependencies.

So I doubted that classpath is not including the Gson. So I ran maven with -X and noticed some clues.

[DEBUG] Could not find metadata com.example.libraries:Symbology:1.0.0-SNAPSHOT/maven-metadata.xml in local (C:\Users\ra\.m2\repository) [DEBUG] Skipped remote update check for com.example.libraries:Symbology:1.0.0-SNAPSHOT/maven-metadata.xml, locally cached metadata up-to-date. [DEBUG] Could not find metadata com.example.libraries:Symbology:1.0.0-SNAPSHOT/maven-metadata.xml in local (C:\Users\ra\.m2\repository) [DEBUG] Skipped remote update check for com.example.libraries:Symbology:1.0.0-SNAPSHOT/maven-metadata.xml, locally cached metadata up-to-date. [WARNING] The POM for com.example.libraries:Symbology:jar:1.0.0-SNAPSHOT is invalid, transitive dependencies (if any) will not be available: 2 problems were encountered while building the effective model for com.example.libraries:Symbology:1.0.0-SNAPSHOT [ERROR] 'dependencies.dependency.artifactId' for ::jar is missing. @ [ERROR] 'dependencies.dependency.groupId' for ::jar is missing. @

I have a project which depends on Symbology project and this in turn uses Gson. But now from this log I am seeing transitive dependencies are not getting included. So Gson class is not being found.

Here is the Symbology pom:

<project xmlns="maven.apache/POM/4.0.0" xmlns:xsi="www.w3/2001/XMLSchema-instance" xsi:schemaLocation="maven.apache/POM/4.0.0 maven.apache/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.example.libraries</groupId> <artifactId>Symbology</artifactId> <version>1.0.0-SNAPSHOT</version> <packaging>jar</packaging> <name>Symbology</name> <url>maven.apache</url> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> </properties> <dependencies> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.10</version> <scope>test</scope> </dependency> <dependency> <groupId>com.google.code.gson</groupId> <artifactId>gson</artifactId> <version>2.1</version> </dependency> <dependency> <groupId>log4j</groupId> <artifactId>log4j</artifactId> <version>1.2.16</version> </dependency> </dependencies>

Here is the Pom of my project which is calling symbology :

xsi:schemaLocation="maven.apache/POM/4.0.0 maven.apache/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.example.libraries</groupId> <artifactId>FGF</artifactId> <version>1.0.0-SNAPSHOT</version> <packaging>jar</packaging> <distributionManagement> <snapshotRepository> <id>example</id> <name>example-snapshots</name> <url>example/artifactory/libs-snapshots-local</url> </snapshotRepository> </distributionManagement> <name>FGF</name> <url>maven.apache</url> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> </properties> <dependencies> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.10</version> <scope>test</scope> </dependency> <dependency> <groupId>log4j</groupId> <artifactId>log4j</artifactId> <version>1.2.16</version> </dependency> <dependency> <groupId>com.example.libraries</groupId> <artifactId>Category</artifactId> <version>1.0.0-SNAPSHOT</version> </dependency> <dependency> <groupId>com.example.libraries</groupId> <artifactId>Time</artifactId> <version>1.0.0-SNAPSHOT</version> </dependency> <dependency> <groupId>com.example.libraries</groupId> <artifactId>Display</artifactId> <version>1.0.0-SNAPSHOT</version> </dependency> **<dependency> <groupId>com.example.libraries</groupId> <artifactId>Symbology</artifactId> <version>1.0.0-SNAPSHOT</version> </dependency>** <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> <version>3.2.0.BUILD-SNAPSHOT</version> </dependency> <dependency> <groupId>cglib</groupId> <artifactId>cglib</artifactId> <version>2.2.2</version> </dependency> <dependency> <groupId>org.apache.directory.studio</groupId> <artifactId>org.apachemons.lang</artifactId> <version>2.6</version> </dependency> </dependencies>

解决方案

Figured Out the Problem Finally after spending lot of time.

The problem is when I am pushing the symbology artifact to repository it is not pushing the pom into repository. So when I am using the symbology artifact as dependency my project is not able to know what are the transitive dependencies.

So I pushed my pom into repository along with jar and now it is able to get all the dependencies.

HURRAYYYYYYYYYYYYYYYYY!!!!!!!!!!!!!!!!!!