自动创建视图

如何解决自动创建视图

我正在尝试使用Ektorp库从ouchDB中查询数据。我在initStandardDesignDocument（）处得到空指针异常； 如果我在mydatabase中手动创建视图，则代码运行良好。但是无法通过代码自动创建视图。

请在下面找到我的代码：

主类：

package com.example.couchPoC;

import java.net.MalformedURLException;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class DemoApplication {

    
    public static void main(String[] args) throws MalformedURLException {
        SpringApplication.run(DemoApplication.class,args);
        CouchConnector connect = new CouchConnector();
        connect.newRepoView();
        System.out.println("finish");
    }

}

实体类：沙发：

package com.example.couchPoC;
import org.ektorp.support.Typediscriminator;

import com.fasterxml.jackson.annotation.JsonProperty;
@Typediscriminator
public class Sofa {

     private String id;
     private String revision;
     private String color;
     
     @JsonProperty("_id")
     public String getId() {
             return id;
     }

     @JsonProperty("_id")
     public void setId(String s) {
             id = s;
     }

     @JsonProperty("_rev")
     public String getRevision() {
             return revision;
     }

     @JsonProperty("_rev")
     public void setRevision(String s) {
             revision = s;
     }

     public void setColor(String s) {
             color = s;
     }
     
     public String getColor() {
             return color;
     }
}

存储库类：

package com.example.couchPoC;

import java.util.List;

import org.ektorp.CouchDbConnector;
import org.ektorp.ViewQuery;
import org.ektorp.support.CouchDbRepositorySupport;
import org.ektorp.support.GenerateView;
import org.ektorp.support.View;

public class SofarepositoryView extends CouchDbRepositorySupport<Sofa> {
    String designDocName;
    {
        
        initStandardDesignDocument();
        
    }
    public SofarepositoryView(Class<Sofa> type,CouchDbConnector db,String designDocName) {
        super(type,db,designDocName);
        this.designDocName = "_design/" + designDocName;
    }

    
        @Override
        @View( name="all",map = "function(doc) { if (doc.title) { emit(doc.dateCreated,doc._id) } }")
        public List<Sofa> getAll() {          
            return  queryView("all");
        }
        
        @GenerateView
        public List<Sofa> findByColor(String color) {
            return queryView("by_color",color);
        }

}

CouchConnector.java：

package com.example.couchPoC;

import java.net.MalformedURLException;
import java.util.List;

import org.ektorp.CouchDbConnector;
import org.ektorp.CouchDbInstance;
import org.ektorp.http.HttpClient;
import org.ektorp.http.StdHttpClient;
import org.ektorp.impl.NameConventions;
import org.ektorp.impl.StdCouchDbConnector;
import org.ektorp.impl.StdCouchDbInstance;

public class CouchConnector {
    HttpClient httpClient;
    CouchDbInstance dbInstance;
    CouchDbConnector db;
    CouchConnector() throws MalformedURLException
    {
            httpClient = new StdHttpClient.Builder()
            .url("http://localhost:5984").username("admin").password("admin")
            .build();
         dbInstance = new StdCouchDbInstance(httpClient);
       db = new StdCouchDbConnector("mydatabase",dbInstance);
        db.createDatabaseIfNotExists();  
         String stdDesignDocumentId = NameConventions.designDocName("_design/Sofa");
         System.out.println();
         Sofa newSofa = new Sofa();
            newSofa.setColor("black");
            newSofa.setId("sofa1");
            db.create(newSofa);
            Sofa newSofa1 = new Sofa();
            newSofa1.setColor("blue");
            newSofa1.setId("sofa2");
            db.create(newSofa1);
        Sofa sofa = db.get(Sofa.class,"sofa1");
        sofa.setColor("white");
        db.update(sofa);
            }
        
    public void newRepoView()
    {
        SofarepositoryView viewSofas = new SofarepositoryView(Sofa.class,"Sofa");
        List<Sofa> allSofas1= viewSofas.getAll();
        System.out.println("all sofas in DB using view");
        System.out.println(allSofas1.size());
        System.out.println(allSofas1);
        System.out.println(allSofas1.get(0).getId());
        for(int i=0;i<allSofas1.size();i++)
        {
            System.out.println(allSofas1.get(i).getId()+" - "+allSofas1.get(i).getColor());
        }
        List<Sofa> filterSofa = viewSofas.findByColor("blue");
        System.out.println("filtered sofas in DB using view");
        for(int i=0;i<allSofas1.size();i++)
        {
            System.out.println(filterSofa.get(i).getId()+" - "+filterSofa.get(i).getColor());
        }
    }
    
}