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在 Primefaces 2.2 中，如果要获取 DataTable 选择，则需要在没有验证失败或转换器失败的情况下提交数据表。

如下所示：

        <p:dataTable update="outputPanel" id="dataTable" var="car" 
                value="#{tableBean.cars}" selection="#{tableBean.selectedCars}">

                <p:column selectionMode="multiple" />
                <p:column style="width:200px" id="Model">
                    <f:facet name="header">
                        Model
                   </f:facet>
                    <h:outputText value="#{car.model}" />
                    <h:inputText value="#{car.model}" >
                        <f:attribute name="datatableClientId" value="form:dataTable" />
                        <f:attribute name="datatable" value="#{dataTableBinding}" />
                        <f:validator validatorId="dataTableRequiredValidator" />
                    </h:inputText>
                </p:column>

            </p:dataTable>

当validator失效时，如何获取validator中的selectedCars？

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1 回答 1

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我查看了 Primefaces 2.2 源代码，解码数据表时将使用 DataHelper 类来解码选择。所以我复制代码来编写一个 util 类，如下所示：

//when the validator in a row, the datatable clientId will be wrong append the row number. so please specify the table clientId.
    public Object getDataTableSelection(FacesContext context, DataTable table, String dataTableclientId) {
        String clientId = dataTableclientId != null ? dataTableclientId : table.getClientId(context);
        Map<String, String> params = context.getExternalContext().getRequestParameterMap();

        String selection = params.get(clientId + "_selection");
        Object data = null;
        if (table.isSingleSelectionMode()) {
            data = decodeSingleSelection(table, selection);
        } else {
            data = decodeMultipleSelection(table, selection);
        }
        table.setRowIndex(-1); // clean
        return data;
    }

    private Object decodeSingleSelection(DataTable table, String selection) {
        Object data = null;
        if (isValueBlank(selection)) {
            table.setSelection(null);
            table.setEmptySelected(true);

        } else {
            int selectedRowIndex = Integer.parseInt(selection);
            int first = table.getFirst();
            int rows = table.getRows();
            int last = rows == 0 ? table.getRowCount() : rows;

            if (first <= selectedRowIndex && (first + last) > selectedRowIndex) {
                table.setRowIndex(selectedRowIndex);
                data = table.getRowData();
                table.setSelection(table.getRowData());
            }
        }
        return data;
    }

    private boolean isValueBlank(String value) {
        if (value == null)
            return true;

        return value.trim().equals("");
    }

    private Object decodeMultipleSelection(DataTable table, String selection) {
        Class<?> clazz =
            table.getValueExpression("selection").getType(FacesContext.getCurrentInstance().getELContext());
        Object data = null;
        if (isValueBlank(selection)) {
            data = Array.newInstance(clazz.getComponentType(), 0);
            table.setSelection(data);

        } else {
            if (!table.isCellSelection()) {
                String[] rowSelectValues = selection.split(",");
                data = Array.newInstance(clazz.getComponentType(), rowSelectValues.length);

                for (int i = 0; i < rowSelectValues.length; i++) {
                    table.setRowIndex(Integer.parseInt(rowSelectValues[i]));

                    Array.set(data, i, table.getRowData());
                }
                table.setSelection(data);
            }
        }
        return data;
    }

所以你可以使用该getDataTableSelection(current facescontext instance, datatable instance, table clientId)方法来获取选择。它将返回一个数组对象（永远不会为空）。

注意：当validator在一行时，datatable的clientId会错误的追加行号。所以请指定表clientId。

于 2013-02-27T08:42:56.593 回答