将多个视图参数传递给具有复合主键的实体的转换器

Question

如何为具有复合主键的实体编写转换器?

我想用URl编辑实体，例如' edit_representative.xhtml ? emp_id = 12345, project_id = 45

我用的是Omnifaces对于单主键

<o:viewParam name="emp_id" value="#{projectRepEdit.projectRep}"
converter="#{projectRepConverter}"
converterMessage="Bad request. Unknown Project Representative." required="true"
requiredMessage="Bad request. Please use a link from within the system." />

但是我如何将员工正在处理的project_id传递给转换器

编辑

根据BalusC的回答，我使用了第二个选项，并在我的projectRepConverter转换器中有以下内容

String project_id = (String) component.getAttributes().get("project_id");
String emp_id= (String) component.getAttributes().get("emp_id");
ProjectRep prjRep = prjRepRepository.getByEmpIdAndProjectId(emp_id,project_id);
return prjRep;

和facelets

<f:metadata>
<o:viewParam name="project_id" value="#{projectRepEdit.project}"
    converter="#{projectConverter}"
    converterMessage="Bad request. Unknown Project." required="true"
    requiredMessage="Bad request. Please use a link from within the system." />
<o:viewParam name="badge" value="#{projectRepEdit.projectRep}"
    converter="#{projectRepConverter}"
    converterMessage="Bad request. Unknown Project Rep." required="true"
    requiredMessage="Bad request. Please use a link from within the system.">
    <f:attribute name="project_id" value="#{param.project_id}" />
    <f:attribute name="emp_id" value="#{param.emp_id}" />
</o:viewParam>

Answer 1

<f:viewParam>和<o:viewParam>不支持多参数。您需要手动获取参数。我可以想到两种基本方法:

1. 在转换器中获取它作为请求参数:

   String project_id = FacesLocal.getRequestParameter(context, "project_id");
   

   ---

2. 或者将其作为组件属性传递:

   <o:viewParam ...>
       <f:attribute name="project_id" value="#{param.project_id}" />
   </o:viewParam>
   

   这样你就可以在转换器中按如下方式获取它:

   String project_id = (String) component.getAttributes().get("project_id");
   

   ---

选择哪种方式取决于转换器的预期可重用性。例如，您可以使用第二种方法将project_id属性名称重命名为compound_key左右，并使其可重用。