问:导入javax.annotation.Generated

Question

当导入包时，im得到的错误是:包javax.annotation不可访问。编译时的错误，因为我不能使用代码中生成的向下是:错误发生在启动层初始化期间

java.lang.module.FindException:无法派生C:\Users"NAME".p2\pool\plugins\es.ucm.gaia.colibristudio.LibraryPool_1.0.0\lib\databaseconnector\jboss-transaction-api_1.1_spec-1.0.0.Final.jar的模块描述符，原因: java.lang.IllegalArgumentException: jboss.transaction.api.1.1.spec:无效的模块名称：'1‘不是Java标识符

代码是：

import jcolibri.cbraplications.StandardCBRApplication;
import jcolibri.cbrcore.CBRCase;
import jcolibri.cbrcore.CBRCaseBase;
import jcolibri.cbrcore.CBRQuery;
import jcolibri.cbrcore.Connector;
import jcolibri.exception.ExecutionException;
import jcolibri.exception.InitializingException;
import jcolibri.method.retrieve.NNretrieval.NNConfig;
 
import javax.annotation.Generated;  //This is where im getting the error and 
                                   //every Generated after does not work
import representation.CaseDescription;
import representation.CaseSolution;
import jcolibri.method.retrieve.NNretrieval.NNConfig;
import jcolibri.cbrcore.Attribute;
import jcolibri.method.retrieve.RetrievalResult;
import jcolibri.method.retrieve.NNretrieval.NNScoringMethod;
import jcolibri.method.retrieve.selection.SelectCases;
import java.util.Collection;
 
public class CBRApplication implements StandardCBRApplication {
 
    @Generated(value = { "ColibriStudio" })
    Connector connector;
   
    @Generated(value = { "ColibriStudio" })
    CBRCaseBase casebase;
 
 
 
    //******************************************************************/
    // Configuration
    //******************************************************************/
 
    @Override
    public void configure() throws ExecutionException {
        try{
            configureConnector();
            configureCaseBase();
        } catch (Exception e){
            throw new ExecutionException(e);
        }
    }
 
    /** Configures the connector */
    @Generated(value = { "CS-PTConector" })
    private void configureConnector() throws InitializingException{
        connector = new jcolibri.connector.PlainTextConnector();
        connector.initFromXMLfile(jcolibri.util.FileIO.findFile("config/plainTextConnectorConfig.xml"));
    }
 
    /** Configures the case base */
    @Generated(value = { "CS-CaseManager" })   
    private void configureCaseBase() throws InitializingException{
        casebase = new jcolibri.casebase.LinearCaseBase();
    }
 
    //******************************************************************/
    // Similarity
    //******************************************************************/
   
    /** Configures the similarity */
    @Generated(value = { "CS-Similarity" })
    private NNConfig getSimilarityConfig() {
        NNConfig simConfig = new NNConfig();
        simConfig.setDescriptionSimFunction(new jcolibri.method.retrieve.NNretrieval.similarity.global.Average());
        Attribute attribute0 = new Attribute("HolidayType", CaseDescription.class);
        simConfig.addMapping(attribute0, new jcolibri.method.retrieve.NNretrieval.similarity.local.Equal());
        simConfig.setWeight(attribute0, 1.00);
        Attribute attribute1 = new Attribute("NumberOfPersons", CaseDescription.class);
        simConfig.addMapping(attribute1, new jcolibri.method.retrieve.NNretrieval.similarity.local.Equal());
        simConfig.setWeight(attribute1, 1.00);
        Attribute attribute2 = new Attribute("Region", CaseDescription.class);
        simConfig.addMapping(attribute2, new jcolibri.method.retrieve.NNretrieval.similarity.local.Equal());
        simConfig.setWeight(attribute2, 1.00);
        Attribute attribute3 = new Attribute("Transportation", CaseDescription.class);
        simConfig.addMapping(attribute3, new jcolibri.method.retrieve.NNretrieval.similarity.local.Equal());
        simConfig.setWeight(attribute3, 1.00);
        Attribute attribute4 = new Attribute("Duration", CaseDescription.class);
        simConfig.addMapping(attribute4, new jcolibri.method.retrieve.NNretrieval.similarity.local.Equal());
        simConfig.setWeight(attribute4, 1.00);
        Attribute attribute5 = new Attribute("Season", CaseDescription.class);
        simConfig.addMapping(attribute5, new jcolibri.method.retrieve.NNretrieval.similarity.local.Equal());
        simConfig.setWeight(attribute5, 1.00);
        Attribute attribute6 = new Attribute("Accommodation", CaseDescription.class);
        simConfig.addMapping(attribute6, new jcolibri.method.retrieve.NNretrieval.similarity.local.Equal());
        simConfig.setWeight(attribute6, 1.00);
        return simConfig;
    }
 
    //******************************************************************/
    // Methods
    //******************************************************************/
   
 
    @Generated(value = { "ColibriStudio" })
    @Override
    public CBRCaseBase preCycle() throws ExecutionException {
        casebase.init(connector);
        return casebase;
    }
       
    @Generated(value = { "ColibriStudio" })
    @Override
    public void cycle(CBRQuery query) throws ExecutionException {
        NNConfig simConfig = getSimilarityConfig();
        Collection<RetrievalResult> eval = NNScoringMethod.evaluateSimilarity(casebase.getCases(), query, simConfig);
        eval = SelectCases.selectTopKRR(eval, 5);
        System.out.println("Retrieved cases:");
        for (RetrievalResult nse : eval)
            System.out.println(nse);
    }
 
    @Generated(value = { "ColibriStudio" })
    @Override
    public void postCycle() throws ExecutionException {
        connector.close();
    }
 
    /**
     * Main method
     */
    @Generated(value = { "ColibriStudio" })
    public static void main(String[] args) {
        CBRApplication cbrApp = new CBRApplication();
        try {
            cbrApp.configure();
            CBRCaseBase caseBase = cbrApp.preCycle();
           
            for(CBRCase c: caseBase.getCases())
                System.out.println(c);
           
        } catch (ExecutionException e) {
            e.printStackTrace();
        }
 
    }
}

Answer 1

如果Eclipse说“JDK”是不可访问的，那么可能是因为使用了什么javax.annotation来编译您的代码。您希望您的代码需要JDK 1.8编译器吗？

首先要检查的是与您的项目关联的Java Execution Environment名称。如果您需要JDK 1.8，那么在Project Properties and Java Compiler中，它应该引用"JavaSE-1.8“作为执行环境。

您还应该检查执行环境本身的定义。这可以在Eclipse Preferences->Java->InstalledJREs->ExecutionEnvironments中找到。如果单击"JavaSE-1.8"，列表中应该有一个或多个Java发行版，其中一个应该选中，选中的那个发行版的名称应该是"jdk“，而不是"jre”。