解决Bundle中使用反射时,报ClassNotFoundException异常

源代码下载

user-model:

user-model/user:

/**  * @author wumingkun * @version 1.0.0 * @Description */package com.demo.user.user_model;/** * @author wumingkun * */public class User {private int id;private String name;public int getId() {return id;}public void setId(int id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}public String toString() {return "User [id=" + id + ", name=" + name + "]";}}

user-modle/pom.xml

<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.demo.user</groupId><artifactId>user-model</artifactId><version>0.0.1-SNAPSHOT</version><packaging>bundle</packaging><name>user-model</name><url>http://maven.apache.org</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></dependencies><build><plugins><plugin><groupId>org.apache.felix</groupId><artifactId>maven-bundle-plugin</artifactId><extensions>true</extensions><configuration><instructions></instructions></configuration></plugin></plugins></build></project>

user-service:

UserService

/** *  * @author wumingkun * @version 1.0.0 * @Description */package com.demo.user.user_service;/** * @author wumingkun * */public class UserSerivce {public void add(Object obj){System.out.println(obj+" add....");}}

pom.xml

<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.demo.user</groupId>  <artifactId>user-service</artifactId>  <version>0.0.1-SNAPSHOT</version>  <packaging>bundle</packaging>  <name>user-service</name>  <url>http://maven.apache.org</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>  </dependencies>  <build><plugins><plugin><groupId>org.apache.felix</groupId><artifactId>maven-bundle-plugin</artifactId><extensions>true</extensions><configuration><instructions></instructions></configuration></plugin></plugins></build></project>

user-action:

Activator

/** * @author wumingkun * @version 1.0.0 * @Description */package com.demo.user.user_action;import java.lang.reflect.Method;import org.osgi.framework.BundleActivator;import org.osgi.framework.BundleContext;import com.demo.user.user_service.UserSerivce;/** * @author wumingkun * */public class Activator implements BundleActivator {/* (non-Javadoc) * @see org.osgi.framework.BundleActivator#start(org.osgi.framework.BundleContext) */public void start(BundleContext context) throws Exception {try {Class clz=Class.forName("com.demo.user.user_model.User");Object obj=clz.newInstance();Method setIdMethod=clz.getMethod("setId", new Class[]{int.class});setIdMethod.invoke(obj,1);Method setNameMethod=clz.getMethod("setName", new Class[]{String.class});setNameMethod.invoke(obj,"张三");UserSerivce serivce=new UserSerivce();serivce.add(obj);} catch (Exception e) {e.printStackTrace();}}/* (non-Javadoc) * @see org.osgi.framework.BundleActivator#stop(org.osgi.framework.BundleContext) */public void stop(BundleContext context) throws Exception {}}

</pre>pom.xml<pre name="code" class="html"><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.demo.user</groupId><artifactId>user-action</artifactId><version>0.0.1-SNAPSHOT</version><packaging>bundle</packaging><name>user-action</name><url>http://maven.apache.org</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>org.osgi</groupId><artifactId>org.osgi.core</artifactId><version>4.2.0</version></dependency><dependency><groupId>com.demo.user</groupId><artifactId>user-service</artifactId><version>0.0.1-SNAPSHOT</version></dependency></dependencies><build><plugins><plugin><groupId>org.apache.felix</groupId><artifactId>maven-bundle-plugin</artifactId><extensions>true</extensions><configuration><instructions><Bundle-Activator>com.demo.user.user_action.Activator</Bundle-Activator></instructions></configuration></plugin></plugins></build></project>

分析:

从user-action/pom.xml中可以看到它仅仅依赖了user-service,再看Activator.java文件中，import部份:

import java.lang.reflect.Method;import org.osgi.framework.BundleActivator;import org.osgi.framework.BundleContext;import com.demo.user.user_service.UserSerivce;

没有导入 com.demo.user.user_model,

查看MANIFEST.MF

Manifest-Version: 1.0Bnd-LastModified: 1405153337259Build-Jdk: 1.5.0_22Built-By: AdministratorBundle-Activator: com.demo.user.user_action.ActivatorBundle-ManifestVersion: 2Bundle-Name: user-actionBundle-SymbolicName: com.demo.user.actionBundle-Version: 0.0.1.SNAPSHOTCreated-By: Apache Maven Bundle PluginExport-Package: com.demo.user.user_action;version="0.0.1.SNAPSHOT";uses: ="org.osgi.framework"Import-Package: com.demo.user.user_service;version="[0.0,1)",org.osgi.fr amework;version="[1.5,2)"Tool: Bnd-2.1.0.20130426-122213

它只导入了 com.demo.user.user_service及org.osgi.framework

当运行Bundle时就报错了:

java.lang.ClassNotFoundException: com.demo.user.user_model.User

解决办法

user-action/pom.xml的maven-bundle-plugin中,加入Bundle使用的所有外部包

<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.demo.user</groupId><artifactId>user-action</artifactId><version>0.0.1-SNAPSHOT</version><packaging>bundle</packaging><name>user-action</name><url>http://maven.apache.org</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>org.osgi</groupId><artifactId>org.osgi.core</artifactId><version>4.2.0</version></dependency><dependency><groupId>com.demo.user</groupId><artifactId>user-service</artifactId><version>0.0.1-SNAPSHOT</version></dependency></dependencies><build><plugins><plugin><groupId>org.apache.felix</groupId><artifactId>maven-bundle-plugin</artifactId><extensions>true</extensions><configuration><instructions><Bundle-Activator>com.demo.user.user_action.Activator</Bundle-Activator><Import-Package> com.demo.user.user_service,org.osgi.framework,com.demo.user.user_model</Import-Package></instructions></configuration></plugin></plugins></build></project>

再次查看MANIFEST

Manifest-Version: 1.0Bnd-LastModified: 1405154955217Build-Jdk: 1.5.0_22Built-By: AdministratorBundle-Activator: com.demo.user.user_action.ActivatorBundle-ManifestVersion: 2Bundle-Name: user-actionBundle-SymbolicName: com.demo.user.actionBundle-Version: 0.0.1.SNAPSHOTCreated-By: Apache Maven Bundle PluginExport-Package: com.demo.user.user_action;version="0.0.1.SNAPSHOT";uses: ="org.osgi.framework"Import-Package: com.demo.user.user_service;version="[0.0,1)",org.osgi.fr amework;version="[1.5,2)",com.demo.user.user_modelTool: Bnd-2.1.0.20130426-122213

部署运行:

User [id=1, name=张三] add....