Question

我实现了一个延迟加载Datatable，其中包含实现

的primefaces

load(int first, int pageSize, String sortField, SortOrder sortOrder, Map<String,Object> filters)

现在我需要将参数从我的页面传递给此方法（即，我的页面中有一个过滤器部分，过滤器不是表格的一部分，而且是独立的对象！）。我的参数存储在页面的托管bean中。

我怎样才能做到这一点？

谢谢！

Answer 1

使参数成为bean的属性，并将它们直接传递给从db获取数据的服务（在本例中，服务是EJB MyObjFacade myObjFacade）：

@ManagedBean
@ViewScoped
public class MyBean {
    @EJB
    private MyObjFacade myObjFacade;
    private LazyDataModel<MyObjType> model;        // getter
    private MyParameter myParameter;

    @PostConstruct
    public void init() {
        model = new LazyDataModel<MyObjType> () {

            @Override
            public List<MyObjType> load(int first, int pageSize, String sortField, SortOrder sortOrder, Map<String, String> filters) {
                model.setRowCount(myObjFacade.count(filters, myParameter));
                return myObjFacade.getResultList(first, pageSize, sortField, sortOrder, filters, myParameter);
            }
        };
        model.setRowCount(myObjFacade.count(new HashMap<String, String> ()));
    }
}

您只需提供实施count和getResultList方法的服务。

Answer 2

经过几个小时的搜索，我终于做到了。我将这个解决方案留在这里以供进一步参考。

//Managed Bean - View
public class DummyLazySearchPageBean {

    private LazyDataModel<DummyObject> results;
    private String searchFilter;//to simulate search filter
    private DummyBusinessClass dummyBusinessClass;

    public DummyLazySearchPageBean() {
        results = new SearchsLazyLoader();
    }

    // GETTERS AND SETTERS

    @SuppressWarnings("serial")
    private final class SearchsLazyLoader extends LazyDataModel<DummyObject> {
        @Override  
        public List<DummyObject> load(int first, int pageSize, String sortField, SortOrder sortOrder, Map<String,Object> filters) {
//Simulate BD model         
List<DummyObject> data = new ArrayList<DummyObject>();
            dummyBusinessClass = new DummyBusinessClass();

            data = dummyBusinessClass.search(searchFilter, 5000);

            //rowCount
            this.setRowCount(data.size());

              //paginate
              if(data.size() > pageSize) {
                  try {
                      return data.subList(first, first + pageSize);
                  }
                  catch(IndexOutOfBoundsException e) {
                      return data.subList(first, first + (data.size() % pageSize));
                  }
              }
              else {
                  return data;
              }
        }
    }

    public final void search(){
        results = new SearchsLazyLoader();
    }
}

Answer 3

使用参数输入创建SearchsLazyLoader的构造函数。这是我的代码示例：

package com.mandiri.askes.model.lazy;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;

import org.apache.commons.lang3.StringUtils;
import org.hibernate.Query;
import org.hibernate.Session;
import org.primefaces.model.LazyDataModel;
import org.primefaces.model.SortOrder;

import com.mandiri.askes.model.Participant;
import com.mandiri.askes.utils.CallAble;
import com.mandiri.askes.utils.HibernateUtil;

public class LazyPesertaDataModel extends LazyDataModel<Participant> {
    private static final long serialVersionUID = 1L;
    private String keyword;

    public LazyPesertaDataModel(String keyword) {
        if (StringUtils.isNotEmpty(keyword)) {
            this.keyword = keyword;
        }else{
            this.keyword = "";
        }       
    }

    /**
     * Collect Peserta Badan Usaha as Data Model Primefaces
     * 
     */
    @Override
    public List<Participant> load(int first, int pageSize, String sortField,
            SortOrder sortOrder, Map<String, String> filters) {

        List<Participant> listPesertaBpjs = new ArrayList<Participant>();

        listPesertaBpjs = getLazyDataPeserta(first, pageSize, sortField);

        this.setRowCount(countAllRecord());

        return listPesertaBpjs;
    }

    /**
     * Get Peserta Data using hibernate pagination <b>(Lazy Loading)</b> Technique.
     * 
     * @author Dibrut
     * @param firstRecord
     * @param maxResult
     * @return
     */
    @SuppressWarnings("unchecked")
    public List<Participant> getLazyDataPeserta(final int firstRecord, final int maxResult, final String sortField) {
        return HibernateUtil.doInTransaction(new CallAble<List<Participant>>() {

            @Override
            public List<Participant> call(Session session) throws Exception {

                List<Participant> pesertaList = new ArrayList<Participant>();
                String hql = "FROM com.dibrut.learn.model.Participant P"
                        + " WHERE P.name LIKE :keyword";

                Query query = session.createQuery(hql).setFirstResult(firstRecord).
                        setMaxResults(maxResult).setString("keyword", "%"+keyword+"%");

                pesertaList = query.list();
                return pesertaList;
            }
        });     
    }

    /**
     * Count total participant
     * @return
     * @author Dibrut
     */
    public int countAllRecord(){
        return HibernateUtil.doInTransaction(new CallAble<Integer>() {

            @Override
            public Integer call(Session session) throws Exception {             
                String hql = "FROM com.dibrut.learn.model.Participant P"
                        + " WHERE P.name LIKE :keyword";

                Long totalPesertaBu = (Long) session.createQuery(hql).                      
                        setString("keyword", "%"+ keyword+"%").
                        uniqueResult(); 

                return totalPesertaBu.intValue();
            }
        });     
    }

    public String getKeyword() {
        return keyword;
    }

    public void setKeyword(String keyword) {
        this.keyword = keyword;
    }

}

如果要搜索数据，只需使用managedBean属性的参数调用构造函数。例如，您在ManagedBean中有searchParticipant方法：

public void searchParticipant() {
    this.participantLazyModel = new LazyPesertaDataModel(this.keyword);     
}

其中关键字是页面中inputText的值。

如何将参数传递给Primefaces LazyDataModel加载函数

3 个答案: