Java项目无法引用另一个项目

Question

我正在使用 Eclipse。我正在构建一个 RESTful 项目 (WarehouseService)，它在构建路径中包含另一个项目 (WarehouseEntity)。当 WarehouseService 从 WarehouseEntity 实例化 StockTakeService 类的对象时(如下所示)，

@POST
@Consumes("application/xml")
public Response updateStockTake(String input){
    warehouse.entity.StockTake st = null;

    try{
        StockTakeService sts = new StockTakeService();

        SAXParserFactory saxFactory = SAXParserFactory.newInstance();
        SAXParser saxParser = saxFactory.newSAXParser();

我收到以下错误。

Apr 13, 2012 12:41:31 AM com.sun.jersey.spi.container.ContainerResponse mapMappableContainerException
SEVERE: The exception contained within MappableContainerException could not be mapped to a response, re-throwing to the HTTP container
java.lang.NoClassDefFoundError: service/warehouse/entity/StockTakeService
    at warehouseservice.jaxrs.StockTake.updateStockTake(StockTake.java:36)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.sun.jersey.server.impl.model.method.dispatch.AbstractResourceMethodDispatchProvider$ResponseOutInvoker._dispatch(AbstractResourceMethodDispatchProvider.java:187)
at com.sun.jersey.server.impl.model.method.dispatch.ResourceJavaMethodDispatcher.dispatch(ResourceJavaMethodDispatcher.java:70)
at com.sun.jersey.server.impl.uri.rules.HttpMethodRule.accept(HttpMethodRule.java:279)
at com.sun.jersey.server.impl.uri.rules.ResourceClassRule.accept(ResourceClassRule.java:86)
at com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:136)
at com.sun.jersey.server.impl.uri.rules.RootResourceClassesRule.accept(RootResourceClassesRule.java:74)
at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1357)
at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1289)
at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1239)
at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1229)
at com.sun.jersey.spi.container.servlet.WebComponent.service(WebComponent.java:420)
at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:497)
at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:684)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:602)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.ClassNotFoundException: service.warehouse.entity.StockTakeService
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1680)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1526)
... 31 more

Apr 13, 2012 12:41:31 AM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet JAX-RS Servlet threw exception
java.lang.ClassNotFoundException: service.warehouse.entity.StockTakeService
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1680)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1526)
at warehouseservice.jaxrs.StockTake.updateStockTake(StockTake.java:36)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.sun.jersey.server.impl.model.method.dispatch.AbstractResourceMethodDispatchProvider$ResponseOutInvoker._dispatch(AbstractResourceMethodDispatchProvider.java:187)
at com.sun.jersey.server.impl.model.method.dispatch.ResourceJavaMethodDispatcher.dispatch(ResourceJavaMethodDispatcher.java:70)
at com.sun.jersey.server.impl.uri.rules.HttpMethodRule.accept(HttpMethodRule.java:279)
at com.sun.jersey.server.impl.uri.rules.ResourceClassRule.accept(ResourceClassRule.java:86)
at com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:136)
at com.sun.jersey.server.impl.uri.rules.RootResourceClassesRule.accept(RootResourceClassesRule.java:74)
at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1357)
at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1289)
at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1239)
at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1229)
at com.sun.jersey.spi.container.servlet.WebComponent.service(WebComponent.java:420)
at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:497)
at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:684)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:602)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Unknown Source)

WarehouseService 是我的 RESTful 项目，WarehouseEntity 是我的 JPA 项目。

我尝试包含另一个项目(WarehouseDBSync)，并实例化 WarehouseDBSync 中的类对象。同样的时间发生。

我是 RESTful 和 JPA 的新手。我不知道是否需要配置任何东西。我觉得将项目包含在构建路径中不起作用，但我不知道还能做什么。

Answer 1

如果您在 Eclipse 中包含另一个项目(Java 构建路径 -> 项目)，您的类将在“编译”时可用。如果您还想将其 Jar 部署到服务器(可能是 lib 目录)，您还必须在与“Java Build Path”相同的菜单中的“Deploy Assembly”中编写一个条目。