如何访问流中的setter和setter

Question

我有一个获取json对象并将其插入aws弹性搜索服务的方法，但我想编写另一个方法，该方法接受多个json对象并将它们插入到aws弹性搜索中。

/**
 * Create the Product in ElasticSearch
 *
 * @param product The Product
 * @return The response string
 * @throws JsonProcessingException Throws JsonProcessingException when response cannot be parsed
 */
public String createNewProduct(Product product) throws JsonProcessingException {
    final ObjectMapper objectMapper = new ObjectMapper();
    final String json = objectMapper.writeValueAsString(product);
    if (json != null) {
        AwsResponse response = createDocument(ElasticSearchConstants.PRODUCTS_INDEX,
            ElasticSearchConstants.PRODUCTS_DOCUMENT_TYPE,
            json,
            product.getPartNo());
        // Creating a new document not seen before results in a 201 status, where as overwriting a previous document results in a 200
        if (response != null && (response.getHttpResponse().getStatusCode() == HttpStatus.CREATED.value()
            || response.getHttpResponse().getStatusCode() == HttpStatus.OK.value())) {
            LOGGER.info("Successfully created new Product", product.getPartNo(), product.getLevelOne());
            return product.getPartNo();
        }
    }

    return null;
}

/**
 * Create new Products in ElasticSearch
 * @param products The product
 * @throws JsonProcessingException Throws JsonProcessingException when response cannot be parsed
 */
public String createNewProducts(ArrayList<Product> products) throws JsonProcessingException{
    final ObjectMapper objectMapper = new ObjectMapper();
    products.stream()
        .map(product -> {
          try {
              return objectMapper.writeValueAsString(product);
          } catch (JsonProcessingException e) {
              return new JsonProcessingException(e){};
          }
      })
      .forEach(product -> {
          createDocument(ElasticSearchConstants.PRODUCTS_INDEX,
              ElasticSearchConstants.PRODUCTS_DOCUMENT_TYPE,
              product,
              products.stream().forEach(p->p::getPartNo)
              );
      });




    return null;
}

正如您所看到的，createDocument方法采用4个参数，其中4个是字符串，第一个方法工作得很好，但是第二个方法有问题。当我试图获得partNo's时，它会给我一个错误，因为正常情况下，“”如何使它工作。

Answer 1

您不需要map操作，forEach可以在您的情况下工作。在这种情况下，使用streams也不是很有效。您可以简单地编写一个for循环并按以下方式执行该操作：

for (Product product : products) {
    String json = objectMapper.writeValueAsString(product);
    // handle the exception as well above
    createDocument(ElasticSearchConstants.PRODUCTS_INDEX,
            ElasticSearchConstants.PRODUCTS_DOCUMENT_TYPE,
            json, product.getPartNo());
}