Question

我有一个采用json对象并将其插入到aws弹性搜索服务中的方法，但我想编写另一种采用多个json对象并将其插入到aws弹性搜索中的方法

/**
 * 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;
}

如您所见，createDocument方法需要4个参数，其中4个是字符串第一种方法确实很好用，但是第二种方法有问题。当我尝试获取partNo时，它像正常的“ void is notfunctional interface”一样给我一个错误，我该如何使其正常工作。

Answer 1

您不需要执行map，forEach可以解决您的情况。在这种情况下，stream的使用也不是很有效。您可以简单地编写一个for循环并按以下步骤执行操作：

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());
}

如何在流中访问获取器和设置器

1 个答案: