我在Wicket中遇到了SortableDataProvider和DataTable的问题。
我已经定义了我的DataTable:
IColumn<Column>[] columns = new IColumn[9];
//column values are mapped to the private attributes listed in ColumnImpl.java
columns[0] = new PropertyColumn<Column>(new Model<String>("#"), "columnPosition", "columnPosition");
columns[1] = new PropertyColumn<Column>(new Model<String>("Description"), "description");
columns[2] = new PropertyColumn<Column>(new Model<String>("Type"), "dataType", "dataType");
将其添加到表格中:
DataTable<Column> dataTable = new DataTable<Column>("columnsTable", columns, provider, maxRowsPerPage) {
@Override
protected Item<Column> newRowItem(String id, int index, IModel<Column> model) {
return new OddEvenItem<Column>(id, index, model);
}
};
我的数据提供商:
public class ColumnSortableDataProvider extends SortableDataProvider<Column> {
private static final long serialVersionUID = 1L;
private List<Column> list = null;
public ColumnSortableDataProvider(Table table, String sortProperty) {
this.list = Arrays.asList(table.getColumns().toArray(new Column[0]));
setSort(sortProperty, true);
}
public ColumnSortableDataProvider(List<Column> list, String sortProperty) {
this.list = list;
setSort(sortProperty, true);
}
@Override
public Iterator<? extends Column> iterator(int first, int count) {
/*
first - first row of data
count - minimum number of elements to retrieve
So this method returns an iterator capable of iterating over {first, first+count} items
*/
Iterator<Column> iterator = null;
try {
if(getSort() != null) {
Collections.sort(list, new Comparator<Column>() {
private static final long serialVersionUID = 1L;
@Override
public int compare(Column c1, Column c2) {
int result=1;
PropertyModel<Comparable> model1= new PropertyModel<Comparable>(c1, getSort().getProperty());
PropertyModel<Comparable> model2= new PropertyModel<Comparable>(c2, getSort().getProperty());
if(model1.getObject() == null && model2.getObject() == null)
result = 0;
else if(model1.getObject() == null)
result = 1;
else if(model2.getObject() == null)
result = -1;
else
result = ((Comparable)model1.getObject()).compareTo(model2.getObject());
result = getSort().isAscending() ? result : -result;
return result;
}
});
}
if (list.size() > (first+count))
iterator = list.subList(first, first+count).iterator();
else
iterator = list.iterator();
}
catch (Exception e) {
e.printStackTrace();
}
return iterator;
}
问题如下: - 我单击列标题按该列排序。 - 我导航到另一个页面 - 我单击Back(如果我执行相反的操作,则单击Forward) - 页面已过期。
使用PageParameters生成页面会很好,但我不知何故需要拦截sort事件。
任何指针都将非常感激。非常感谢!!
答案 0 :(得分:0)
我很快就不知道可能导致这种情况的原因,但为了帮助诊断,您可能希望为org.apache.wicket.Session
或更多的wicket代码启用调试日志记录。
页面的检索肯定涉及对方法的调用
public final Page getPage(final String pageMapName, final String path, final int versionNumber)
在这个类中,它有一些调试日志。
有关设置此日志记录的帮助,请查看How to initialize log4j properly?或log4j的文档。