How to insert Bean object which has many child Bean in SolrJ

问题

I have a Bean Class Activity which associates List of Profiles and a User Bean. Now If I am trying to insert this Activity bean in Solr by SOLRJ, it is giving me null pointer exception. The Exception is causing by below piece of code:

public <T> boolean insert (T bean) {
    try {
        UpdateResponse response = solrClient.addBean(bean);
        System.out.println("insert bean ElapsedTime: " + response.getElapsedTime());
        solrClient.commit();
        return true;
    } catch (IOException | SolrServerException e) {
        e.printStackTrace();
    }
    return false;
}

回答1:

Refer below URL for nested document insertion and searching:

Searching for nested Documents in Solr(J)

回答2:

If you are using Solr6 and getting null pointer exception then refer: SOLRJ-6.0.0: Insertion of a bean object which associate list of bean object is giving null pointer exception

However if you are trying to insert a bean which associates nested bean then it will give you the exception: clazz.getName() + " cannot have more than one Field with child=true"

It will be by below piece of code of DocumentObjectBinder Class of SolrJ:

@SuppressForbidden(reason = "Needs access to possibly private @Field annotated fields/methods")
  private List<DocField> collectInfo(Class clazz) {
    List<DocField> fields = new ArrayList<>();
    Class superClazz = clazz;
    List<AccessibleObject> members = new ArrayList<>();

    while (superClazz != null && superClazz != Object.class) {
      members.addAll(Arrays.asList(superClazz.getDeclaredFields()));
      members.addAll(Arrays.asList(superClazz.getDeclaredMethods()));
      superClazz = superClazz.getSuperclass();
    }
    boolean childFieldFound = false;
    for (AccessibleObject member : members) {
      if (member.isAnnotationPresent(Field.class)) {
        AccessController.doPrivileged((PrivilegedAction<Void>) () -> { member.setAccessible(true); return null; });
        DocField df = new DocField(member);
        if (df.child != null) {
          if (childFieldFound)
            throw new BindingException(clazz.getName() + " cannot have more than one Field with child=true");
          childFieldFound = true;
        }
        fields.add(df);
      }
    }
    return fields;
  }

回答3:

HttpSolrServer solr = new HttpSolrServer( SOLR_URL );

        // Docs to submit
        Collection<SolrInputDocument> batch = new ArrayList<SolrInputDocument>();

        // Parent Doc 1, a person mamed John Jones
        SolrInputDocument person1 = new SolrInputDocument();
        person1.addField( "id",            "john_jones" );
        person1.addField( "content_type",  "person"     );
        // "_t" suffix tells Solr that it's text
        person1.addField( "first_name_t",  "John"       );
        person1.addField( "last_name_t",   "Jones"      );
        // states and history used in edismax examples
        person1.addField( "states_t",      "California Nevada Idaho Maine" );
        person1.addField( "history_t",     "safe accident accident accident accident accident" );

        // child docs, the vehicles he owns
        SolrInputDocument p1_car1 = new SolrInputDocument();
        p1_car1.addField( "id",            "jj_car1"    );
        p1_car1.addField( "content_type",  "car"        );
        // For cars "make" is an alias for "manufacturer"
        p1_car1.addField( "make_t",        "Honda"      );
        p1_car1.addField( "model_t",       "Accord"     );

        SolrInputDocument p1_car2 = new SolrInputDocument();
        p1_car2.addField( "id",            "jj_car2"    );
        p1_car2.addField( "content_type",  "car"        );
        p1_car2.addField( "make_t",        "Nissan"     );
        p1_car2.addField( "model_t",       "Maxima"     );

        SolrInputDocument p1_bike1 = new SolrInputDocument();
        p1_bike1.addField( "id",           "jj_bike1"   );
        p1_bike1.addField( "content_type", "bike"       );
        p1_bike1.addField( "make_t",       "Yamaha"     );
        p1_bike1.addField( "model_t",      "Passion"    );

        SolrInputDocument p1_bike2 = new SolrInputDocument();
        p1_bike2.addField( "id",           "jj_bike2"   );
        p1_bike2.addField( "content_type", "bike"       );
        p1_bike2.addField( "make_t",       "Peugeot"    );
        p1_bike2.addField( "model_t",      "Vivacity"   );

        // Add children to parent
        person1.addChildDocument( p1_car1  );
        person1.addChildDocument( p1_car2  );
        person1.addChildDocument( p1_bike1 );
        person1.addChildDocument( p1_bike2 );

        // Add parent to batch
        batch.add( person1 );


        // Parent Doc 2, person mamed Satish Smith
        SolrInputDocument person2 = new SolrInputDocument();
        person2.addField( "id",           "satish_smith" );
        person2.addField( "content_type", "person"       );
        person2.addField( "first_name_t", "Satish"       );
        person2.addField( "last_name_t",  "Smith"        );
        person2.addField( "states_t",     "California Texas California Maine Vermont Connecticut" );
        person2.addField( "history_t",    "safe safe safe safe safe safe safe safe accident" );

        // Vehicles (child docs)
        SolrInputDocument p2_car1 = new SolrInputDocument();
        p2_car1.addField( "id",            "ss_car1"     );
        p2_car1.addField( "content_type",  "car"         );
        p2_car1.addField( "make_t",        "Peugeot"     );
        p2_car1.addField( "model_t",       "iOn"         );
        SolrInputDocument p2_bike1 = new SolrInputDocument();
        p2_bike1.addField( "id",           "ss_bike1"    );
        p2_bike1.addField( "content_type", "bike"        );
        p2_bike1.addField( "make_t",       "Honda"       );
        p2_bike1.addField( "model_t",      "Spree"       );
        // link objects and add to batch
        person2.addChildDocument( p2_car1  );
        person2.addChildDocument( p2_bike1 );
        batch.add( person2 );

        System.out.println( "Adding batch of " + batch.size() + " parent docs" );

        // Submit as a group
        solr.add( batch );
        solr.commit();

回答4:

By using SolrInputDocument class I am able to insert document which contains multiple nested documents, Even addBeans method (Below SolrJ Code) is also doing the same. So should I have to construct SolrInputDocument object for each of my bean for indexing. Is it the only solution.

     public UpdateResponse addBeans(String collection, Collection<?> beans, int commitWithinMs) throws SolrServerException, IOException {
    DocumentObjectBinder binder = this.getBinder();
    ArrayList<SolrInputDocument> docs =  new ArrayList<>(beans.size());
    for (Object bean : beans) {
      docs.add(binder.toSolrInputDocument(bean));
    }
    return add(collection, docs, commitWithinMs);
  }

来源：https://stackoverflow.com/questions/37677538/how-to-insert-bean-object-which-has-many-child-bean-in-solrj