java - 如何在不同的 lambda 表达式中使用 lambda 表达式中的对象

Question

我有这个代码

service.confirm(identity, id)
                .map(confirmationResponse -> InternalToExternalResponse.mapToExternal(confirmationResponse))
                .map(externalResponse->uriBuilder.buildAuthorizeUri(externalResponse))
                .lift(auditOperatorFactory.logRequestURI(identity, AuditCategory.BOOKKEEP));

现在我需要扩展 uriBuilder.buildAuthorizeUri(externalResponse) 以将 confirmationResponse 作为第二个参数

我可以在第二个 lambda 表达式中使用第一个 lambda 表达式的 confirmationResponse 吗？最终代码应该是这样的

service.confirm(identity, id)
                .map(confirmationResponse -> InternalToExternalResponse.mapToExternal(confirmationResponse))
                .map(externalResponse-**>uriBuilder.buildAuthorizeUri(externalResponse,confirmationResponse ))**
                .lift(auditOperatorFactory.logRequestURI(identity, AuditCategory.BOOKKEEP));

Answer 1

您可以组合这两个 lambda 表达式:

service.confirm(identity, id)
                .map(confirmationResponse -> {
                    ExternalResponse externalResponse = InternalToExternalResponse.mapToExternal(confirmationResponse);
                    return uriBuilder.buildAuthorizeUri(externalResponse,confirmationResponse);})
                .lift(auditOperatorFactory.logRequestURI(identity, AuditCategory.BOOKKEEP));

不过，我建议使用较短的 lambda 变量名称:

service.confirm(identity, id)
                .map(cr -> {
                    ExternalResponse er = InternalToExternalResponse.mapToExternal(cr);
                    return uriBuilder.buildAuthorizeUri(er,cr);})
                .lift(auditOperatorFactory.logRequestURI(identity, AuditCategory.BOOKKEEP));