如何使用更具体的泛型类型扩展参数化抽象类？

Question

我不熟悉泛型。我有一个抽象类（1）和一个抽象方法。我有另一个抽象类（2）和一些抽象方法，我希望在一些DTO（3,4）中共享这些抽象方法。我想要一个（1）的具体扩展来处理任何扩展（2）的东西。

1.

//I want R to be anything here
public abstract class AggregatedEmailerRoute<R> extends RouteBuilder {

    public static String EMAILER_ROUTE = "direct:aggregated-emailer-route";
    
@Override
    public void configure() throws Exception {
        from(EMAILER_ROUTE)
                .bean(this, "convertToEmailBody(${body},${headers})")
                .to("mock:wherever");
    }

    protected abstract String convertToEmailBody(List<R> body, Map<String,Object> headers);

public abstract class StagingError { //or should this be an interface?
    public abstract Integer getId();
    public abstract String getErrorNote();
    public abstract LocalDateTime getErrorDate();
}

扩展StagingError的两个类：3.

public class Bill extends StagingError {

    private Integer id;
    private String errorNote;
    private LocalDateTime getErrorDate;
    //other fields, getters/setters

public class Payment extends StagingError {

    private Integer id;
    private String errorNote;
    private LocalDateTime getErrorDate;
    //other fields, getters/setters

public class StagingEmailErrorRoute extends AggregatedEmailerRoute<R extends StagingError> {

    @Override
    public void configure() throws Exception {
        super.configure();

        from(jpa(Bill.class.getName())
                .query("some query")
        )
                .to(EMAILER_ROUTE);

        from(jpa(Payment.class.getName())
                .query("some other query")
        )
                .to(EMAILER_ROUTE);

    }


@Override //But here I want to work on anything that implements StagingError so this method can work on Payment OR Bill 
    protected String convertToEmailBody(List<T extends StagingError> body, Map<String,Object> headers) {
        return 
                body
                .stream()
                .map(e -> "Staging entity ID: " + e.getId() +
                            "\n\tError: " + e.getErrorNote() +
                            "\n\tWhen: " + format("%tc",e.getErrorDate().atZone(EST.get())) +
                            "\n")
                .collect(joining("\n"));

Answer 1

我想你只需要一个抽象类型的字符串还是一个抽象类型的字符串？对不起，如果我错了。。。我不能评论，所以我张贴类似的答案。