Struts 2和业务对象 [英] Struts 2 and business objects

问题描述

在Struts 2类中， http get params由字段变量自动提取。虽然在许多类中重复了类似 userId，groupId，等类字段，但我决定制作一个业务对象类 RequestParams ，并将所有字段放在那里。

In a Struts 2 class where http get params are auto fetched by field variables. While there were repeated such class fields like userId,groupId, etc in many classes, I decided to make one business object class RequestParams in each class and put all the field there.

然后我的所有课程都只有 RequestParams rp; ， getRp（）; 和 setRp（）; rp类将使用getter / setter和 userId 所有其他领域。

Then all my class will have just the RequestParams rp; with getRp(); and setRp(); the rp class will have the userId with getters / setters and all other fields.

现在我看到我必须更换。例如 userId ， getRp（）。 getUserId（）; 第34行现在代码看起来很难看。

Now I see I have to replace. e.g userId with getRp().getUserId(); at line 34 Now the code is looking ugly.

使用： messageId = ChatDao.saveMessage（userId，groupId，message）;

看起来像

rp.setMessageId(  ChatDao.saveMessage(rp.getUserId(), rp.getGroupId(), rp.getMessag()   )   );

这样做的更好方法是什么？

what is a better way of doing such things?

public class SendMessageOrStartChatAction extends BaseActoinSupport{


    private static final long serialVersionUID = 1L;
    private int userId;
    private int groupType;
    private int groupId;
    private String groupTitle;
    private String groupMemberIds;
    private int randomCode;
    private String message;
    private int messageId; //internal class ues


    @Override
    /** boo */
    protected void doExecute() throws IOException {



        //check if it had random code in db, (msg already saved in db)
        if(ChatDao.randomCodeExists(randomCode)){
            messageId = ChatDao.getMessageIdThatMatchesRandomCode(randomCode);  
            write(messageId);

        }else{
            if(groupId <= 0){
            //create group 
                groupId = ChatDao.createChatGroup(userId, groupTitle, groupType);
                String[] memberIdsArray = groupMemberIds.split("=="); 
                ChatDao.addUsersToGroup(groupId, memberIdsArray);
            }
            //save message
            messageId = ChatDao.saveMessage(userId,groupId , message);
            // queued: may be put this in last viewed messages here. may be.
            write(messageId);       
        }

    }

}

推荐答案

这种方法没有错，如果你聚合一个类并想要访问它的属性，那么公共访问器适合你，你也可以通过OGNL访问它们。该操作位于 valueStack 之上，因此表达式看起来会更简单rp.userId。无论如何，没有必要将所有参数传递给方法，您可以使用简化的方法签名

Nothing wrong with this approach, if you aggregate a class and want to access its properties then public accessors are appropriate to you and you could also access them via OGNL. The action is on top of the valueStack, so expression will look much simpler "rp.userId" for example. Anyway there's no need to pass all params to the method, you can use a simplified method signature

ChatDao.saveMessage(rp);  

并在方法内部访问这些参数。

and inside the method access those parameters.

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