我正在使用 primefaces 3.5，带有 glassfish 服务器 3.1.2。我有一个依赖用户选择答案的琐事问题游戏。我有两个表，其中一个是根据它是多选问题还是它的多选问题生成的。虽然我的多项选择数据表工作得很好，但另一个没有。我已经按照展示案例中的示例进行操作，当我选择表中的 2 个并点击它所在的向导上的下一步按钮时，它会取消选择我选择的内容并让我保持在同一页面上。我让它在任何异常上都保持在同一页面上，并且异常是一个空指针，因为“选定的答案”是空的。这是我的桌子。
<p:dataTable
id="multiQuestionTable"
value="#{triviaQuestionsBean.dataModel}"
var="answer"
selection="#{triviaQuestionsBean.selectAnswers}">
<p:column selectionMode="multiple" />
<p:column>
#{answer.answer.testAnswer}
</p:column>
</p:dataTable>
设置和吸气剂：
private QuestionAnswers[] selectAnswers;
public QuestionAnswers[] getSelectAnswers() {
return selectAnswers;
}
public void setSelectAnswers(QuestionAnswers[] selectAnswers) {
this.selectAnswers = selectAnswers;
}
setter 永远不会被调用，但使用的数据模型非常适合单选。如果需要解决我的问题，请告诉我。如果可能，请提供帮助。
公共类 QuestionAnswersDataModel 扩展 ListDataModel 实现 SelectableDataModel {
/**
* This is the question answers data model used to allow for the sorting,
* and selection of items in a JSF dataTable. This is the basic no-arg
* constructor --Important-- This judges the data from the id, so if the ID
* has not been assigned, there will be unpredictable results.
*
*/
public QuestionAnswersDataModel() {
}
/**
* This is the question answers data model used to allow for the sorting,
* and selection of items in a JSF dataTable. This is the constructor where
* the list of elements are instantiated. --Important-- This judges the data
* from the id, so if the ID has not been assigned, there will be
* unpredictable results.
*
* @param data The list of QuestionAnswers to display in the table.
*/
public QuestionAnswersDataModel(List<QuestionAnswers> data) {
super(data);
}
/**
* This takes a "row key" and looks through the wrapped data to find the
* specific QuestionAnswers entity that matches the passed in row key
*
* @param rowKey The key to search with
* @return The QuestionAnswers entity that matches the criteria or null if
* nothing matches
*/
@Override
public QuestionAnswers getRowData(String rowKey) {
/**
* Get the wrapped data (If there was a lot of data you would use a
* query not just a list)
*/
List<QuestionAnswers> answers =
(List<QuestionAnswers>) getWrappedData();
//for each answer
for (QuestionAnswers answer : answers) {
//if the answer's unique identifier matches the row key:
if (answer.getQuestionAnswersId().toString().equals(rowKey)) {
//return it
return answer;
}
}
//if nothing matches return null
return null;
}
/**
* This takes a QuestionAnswers entity object and returns a key for the
* identification of this entity. As this one runs off of the ID of the
* answer, if nothing is assigned to the value, a null key will be returned.
*
* @param answer The answer to generate the key of
* @return The identifier for this object or null if the ID is null
*/
@Override
public Object getRowKey(QuestionAnswers answer) {
//if the answer is null, return null
if (answer == null) {
return null;
}
//else get the answer id
Long id = answer.getQuestionAnswersId();
//if it's null return null
if (id == null) {
return id;
}
//else return the String representation of the id
return id.toString();
}