Spring MVC jsp对象列表 [英] Spring MVC jsp list of objects

问题描述

我使用Spring MVC 3.0和JSP。我有一个对象：

  public class ObjectWrapper {
 private List< SomeTO> someTOs; 
 
  

SomeTO 包含字段如名称和 id 。我如何创建一个用户可以动态添加到 SomeTO 列表的表单？我搜索了它并发现了一些关于 spring：bind 的内容，但对我来说还不清楚。

div>

在表单支持方法中，将列表设置为属于apache commons集合库的LazyList。

  Factory factoryFactory = new Factory（）{
 public Object create（）{
 SomeTO rtVl = new SomeTO（）; 
 return rtVl; 
} 
}; 
 myFormBacking.setSomeTOs（LazyList.decorate（myFormBacking.getSomeTOs））; 
  

然后在表单上，​​当您将数据发送到服务器时，您可以像这样做 p>

 < input name =someTOs [0] .namevalue =/> 
  

如果您使用

 <％@ taglib prefix =formuri =http://www.springframework.org/tags/form％> 
  

然后您可以简单地去。

 < form：input path =someTOs [0] .name/> 
  

在将数据发布到服务器之前，为了简化修剪，请设置集合中元素的数量。因此，如果用户添加了5个TO，那么将该长度值以表单发送。

现在在服务器上，您必须在保存之前修剪列表。这里是修剪功能

  public List< SomeTOs> pruneList（List  List< SomeTOs> rtVl = new ArrayList< SomeTOs>（）; 
 for（int i = 0; i< unpruned.length&&expectedLength; ++ i）{
 rtVl.add（unpruned.get（i）; 
} 
 return rtVl; 
} 
  

这里使用了prune函数提交（保存前）

  wrapper.setSomeTOs（pruneList（wrapper.getSomeTOs（），Integer.parseInt（request.getParameter（ expectedLength）））; 
  

I use Spring MVC 3.0 and JSP. I have an object:

public class ObjectWrapper {
    private List<SomeTO> someTOs;
}

Class SomeTO contains fields like name and id. How can I create a form on which an user can dynamically add to list of SomeTO? I googled it and found something about spring:bind, but it's unclear for me.

解决方案

In the form backing method, set the list to a LazyList which is part of the apache commons collection library.

Factory notificationFactory = new Factory() {
       public Object create() {
            SomeTO rtVl = new SomeTO();
            return rtVl;
        }
 };
myFormBacking.setSomeTOs(LazyList.decorate(myFormBacking.getSomeTOs));

Then on your form, when you send the data to the server you can do it like this

<input name="someTOs[0].name" value="" />

And if your using

<%@taglib prefix="form" uri="http://www.springframework.org/tags/form" %>

then you can simply go.

<form:input path="someTOs[0].name" />

Before posting the data to the server, to make pruning easier, set the number of elements in the collection. So if the user added 5 TOs, then send that length value in the form post.

ON the server now, you must prune the list before you save it. Here is the function for pruning

public List<SomeTOs> pruneList(List<SomeTOs> unpruned,int expectedLength){
    List<SomeTOs> rtVl = new ArrayList<SomeTOs>();
    for (int i = 0; i < unpruned.length && expectedLength; ++i){
         rtVl.add(unpruned.get(i);
    }
    return rtVl;
}

Here is the use of the prune function in the on submit (before save)

wrapper.setSomeTOs(pruneList(wrapper.getSomeTOs(),Integer.parseInt(request.getParameter("expectedLength)));

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