Java汎用の使用およびListソート
2056 ワード
import java.util.ArrayList;
public class ItemList<S extends Comparable, T> extends ArrayList<T> implements
Comparable<ItemList<S, T>> {
private static final long serialVersionUID = 3752285817293910325L;
private S key;
public ItemList(S key) {
this.key = key;
}
public S getKey() {
return key;
}
public int compareTo(ItemList<S, T> o) {
return key.compareTo(o.getKey());
}
}
private void generateReport(List<DbRow> productList) {
Map<Date, ItemList<Date, String>> productMap = new Hashtable<Date, ItemList<Date, String>>();
for (DbRow row : productList) {
DbProduct product = (DbProduct) row;
Date releaseDate = product.getProductReleaseDate();
ItemList<Date, String> list = productMap.get(releaseDate);
if (list == null) {
list = new ItemList<Date, String>(releaseDate);
productMap.put(releaseDate, list);
}
list.add(product.getProNumber() + " " + product.getProName());
}
DateFormat df = new SimpleDateFormat("yyyy-MM-dd");
String tempGoLiveDate = df.format(goLiveDate);
StringWriter tempWriter = new StringWriter();
PrintWriter writer = new PrintWriter(tempWriter);
List<ItemList<Date, String>> releaseList = new ArrayList<ItemList<Date, String>>(productMap.values());
Collections.sort(releaseList);
for (ItemList<Date, String> release : releaseList) {
writer.println(df.format(release.getKey()));
for (String line : release) {
writer.println(line);
}
writer.println();
}
writer.close();
}