qiujy

"但感觉显示层的显示对象还是需要的，要不然有些数据在页面显示会有麻烦"

I think if you have tried JSF a little bit, you will find out that how easy and well JSF handles this matter.

1) In Jsp(or xhtml) pages,the jsf components look like following:

<div class="light col input-field">
     <h:inputText id="mediaName" value="#{mediaBean.media.name}" size="50" maxlength="50" required="true"/>
</div>
 <div class="light col output-field">
      <h:outputText id="mediaComments" value="#{mediaBean.media.comments}"/>
 </div>

<div class="light col input-field">
     <h:selectOneMenu id="format" value="#{mediaBean.media.format.id}" validator="#{mediaBean.validateSelection}" required="true">
          <f:selectItems value="#{mediaBean.tapeFormatList}"/>
     </h:selectOneMenu>
/div>

mediaBean: JSF managed Beans

media: Pojo(+annotation),entity bean

name,comments,format: properties of Entity bean "Media"

tapeFormatList: List<SelectItem>

2) JSF managed bean examples:

public class MediaBean extends CmmManagedBean
{
static final Logger log=Logger.getLogger("MediaBean");

private Media media;

private List tapeSegmentList;

private boolean validAssetFlag;
private boolean validMediaFlag;
private boolean editFlag;
private int labelOffset;
......

}

3) Entity Bean

package uk.co.ondemand.cmm.service.persistence;

import java.util.Date;
import javax.persistence.*;

@Entity
@Table(name = "CMM_MEDIA_ASC")

public class Media extends GenericEntity
{
    @Id
    @GeneratedValue(strategy=GenerationType.SEQUENCE, generator="SEQ")
    @SequenceGenerator(name="SEQ", sequenceName="asset_container_id", allocationSize=1)
    @Column(name = "ID", nullable = false)
    protected long id;

    @Column(name = "CONTAINER_TYPE", nullable = false,insertable=false, updatable=false)
    private String containerType;

    @Column(name = "NAME", nullable = false)
    private String name;

@Column(name = "COMMENTS")
    private String comments;

@JoinColumn(name = "FORMAT", referencedColumnName = "ID")
    @ManyToOne
    private CmmEnumeration format=new CmmEnumeration();

@Transient 

private List foldersList;

//use "Transient" annotion for additional fields not persistent,but used in JSF component value binding for carrying data.

.....

    /** Creates a new instance of Media */
    public Media() {
    }
 
    /**
     * Gets the id of this AssetContainer.
     * @return the id
     */
    public long getId() {
        return this.id;
    }

    /**
     * Sets the id of this AssetContainer to the specified value.
     * @param id the new id
     */
    public void setId(long id) {
        this.id = id;
    }

 .....

    public String getName() {
        return this.name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public CmmEnumeration getFormat() {
        return this.format;
    }

    public void setFormat(CmmEnumeration format) {
        this.format = format;
    }
   ......
}
 

4) You also can use converters for some data type conversion  between pages to models

faces-config.xml

...

<converter>

<converter-for-class>java.lang.Boolean</converter-for-class>
  <converter-class>uk.co.ondemand.cmm.web.jsf.YesNoBooleanConverter</converter-class>
 </converter>
 <converter>
  <converter-for-class>java.util.Date</converter-for-class>
  <converter-class>uk.co.ondemand.cmm.web.jsf.CmmDateTimeConverter</converter-class>
 </converter>
 <converter>
  <converter-for-class>java.sql.Timestamp</converter-for-class>
  <converter-class>uk.co.ondemand.cmm.web.jsf.CmmDateTimeConverter</converter-class>
 </converter>
.....

<managed-bean>
  <managed-bean-name>mediaBean</managed-bean-name>
  <managed-bean-class>uk.co.ondemand.cmm.web.managedbean.MediaBean</managed-bean-class>
  <managed-bean-scope>session</managed-bean-scope>
 </managed-bean>

Hope this is helpful.