NEST客户端在WebApi项目中的使用
本项目的源码已发布在https://gitee.com/lucyliang01/esapi.git
NEST是elastic search为.net 提供的高级客户端依赖组件。
这里我们会建一个web api2项目，进行演示在.net中使用NEST实现文档的增删改查和全文检索
创建web api项目
创建web api2项目，并且修改属性目标框架为.net framework 4.6.1
在nuget中找到NEST依赖，并且安装目前版本7.10.1
创建 ESHelper帮助类文件
配置链接
这里因为对es的连接设置成private static只在创建的时候初始化一次
//单机连接的方式，默认使用articles索引
private static ConnectionSettings settings = new ConnectionSettings(new Uri("http://localhost:9200")).DefaultIndex("articles");
//创建client
private static ElasticClient client = new ElasticClient(settings);
使用attribute自动映射
根据映射的字段创建类Article,并且使用attribute规定映射规则。
1）Number 表示字段类型为数字
2）Text 表示字段类型为字符串，可以进行索引
Analyzer 可以规定索引时的分词工具
Index 为true表示建立索引，并且可以被检索
3）Keyword 表示字段类型为字符串，但是不可以进行索引
4）Date 表示字段类型为日期
[ElasticsearchType(RelationName = "articles")]
public class Article
{
/// <summary>
/// id
/// </summary>
[Number]
public long Id { get; set; }
/// <summary>
/// 标题
/// </summary>
[Text(Analyzer = "ik_max_word", Index = true)]
public string Title { get; set; }
/// <summary>
/// 类型 新闻还是招聘
/// </summary>
[Keyword]
public string Type { get; set; }
/// <summary>
/// 内容
/// </summary>
[Text(Analyzer = "ik_max_word", Index = true)]
public string Content { get; set; }
/// <summary>
/// 新闻作者
/// </summary>
[Keyword]
public string Author { get; set; }
/// <summary>
/// 招聘公司
/// </summary>
[Text(Analyzer = "ik_max_word", Index = true)]
public string Company { get; set; }
/// <summary>
/// 招聘公司地址
/// </summary>
[Text(Analyzer = "ik_max_word", Index = true)]
public string CompanyAddress { get; set; }
/// <summary>
/// 创建时间
/// </summary>
[Date]
public DateTime CreateTime { get; set; }
/// <summary>
/// 访问路径
/// </summary>
[Keyword]
public string WebPath { get; set; }
}
创建映射
在ESHelper中创建映射的方法
/// <summary>
/// 创建映射
/// </summary>
/// <returns></returns>
public static bool CreateMapping()
{
try
{
//映射
CreateIndexResponse createIndexResponse = client.Indices.Create("articles", c => c.Map<Article>(m => m.AutoMap()));
return true;
}
catch (Exception ex)
{
return false;
}
}
在ESController中创建webapi对创建索引的请求
/// <summary>
/// 创建映射
/// </summary>
/// <returns></returns>
[HttpPost, Route("mapping")]
public IHttpActionResult Mapping()
{
return Ok(ESHelper.CreateMapping());
}
创建或者修改单个文档
在ESHelper中创建文档，并且在ESController中创建添加文档的接口，使用postman进行测试
/// <summary>
/// 创建单个文档
/// </summary>
/// <param name="client"></param>
/// <param name="article"></param>
/// <returns></returns>
public static dynamic CreateArticle(Article article)
{
var indexResponse = client.IndexDocument<Article>(article);
return new { flag = true, msg = "操作成功" };
}
/// <summary>
/// 添加一个文档
/// </summary>
/// <param name="article"></param>
/// <returns></returns>
[HttpPost, Route("add")]
public IHttpActionResult Add(Article article)
{
return Ok(ESHelper.CreateArticle(article));
}
批量创建文档
在ESHelper中批量创建文档，并且在ESController中创建批量添加文档的接口，使用postman进行测试
/// <summary>
/// 批量新增
/// </summary>
/// <param name="client"></param>
/// <param name="list"></param>
/// <returns></returns>
public static dynamic CreateBulk(List<Article> list)
{
var bulkAllObservable = client.BulkAll(list, b => b
.Index("articles")
.BackOffTime("30s")
.BackOffRetries(2)
.RefreshOnCompleted()
.MaxDegreeOfParallelism(Environment.ProcessorCount)
.Size(1000)
)
.Wait(TimeSpan.FromMinutes(15), next =>
{
// do something e.g. write number of pages to console
});
return new { flag = true, msg = "操作成功" };
}
/// <summary>
/// 批量添加文档
/// </summary>
/// <param name="list"></param>
/// <returns></returns>
[HttpPost, Route("addBulk")]
public IHttpActionResult addBulk(List<Article> list)
{
return Ok(ESHelper.CreateBulk(list));
}
批量删除
批量删除我们是先根据ids查询出对应的文档，然后进行批量删除
-
根据ids查询多个记录
在ESHelper中根据id批量获取文档
/// <summary> /// 根据id查询 /// </summary> /// <param name="ids"></param> /// <returns></returns> public static List<Article> GetByIds(List<long> ids) { var searchResponse = client.Search<Article>(s => s.Query(q => q.Ids(m => m.Values(ids)))); return searchResponse.Documents.ToList(); } -
批量删除
在ESHelper中批量删除，并且在ESController中创建批量删除文档的接口，使用postman进行测试
/// <summary> /// 批量删除 /// </summary> /// <param name="client"></param> /// <param name="list"></param> /// <returns></returns> public static dynamic DeleteBulk(List<Article> list) { var bulkResponse = client.DeleteMany(list); return new { flag = true, msg = "操作成功" }; }/// <summary> /// 批量删除 /// </summary> /// <param name="ids"></param> /// <returns></returns> [HttpPost, Route("delete")] public IHttpActionResult Delete(List<long> ids) { //根据id获取list var list = ESHelper.GetByIds(ids); return Ok(ESHelper.DeleteBulk(list)); }
全文检索
项目中的全文检索解决方案就是multi match +highlight
multi match 可以对多个字段进行检索并且通过minimum_should_match和boost提高匹配度，
最终的显示结果使用highlight高亮。
在ESHelper中创建全文检索的方法，并且在ESController中创建搜索文档的接口，使用postman进行测试
/// <summary>
/// 全文检索
/// </summary>
/// <param name="page"></param>
/// <param name="keyword"></param>
/// <returns></returns>
public static Dictionary<string, object> Search(int page, string keyword)
{
try
{
int size = 10;
int from = (page - 1) * size;
var searchResponse = client.Search<Article>(s => s
.From(from)
.Size(size)
.Query(q =>
q.MultiMatch(c => c
.Fields(f => f.Field(a => a.Title, 10).Field(a => a.Content).Field(a => a.Company, 10))
.Operator(Operator.Or)//只要有一个词在文档中出现都可以
.MinimumShouldMatch(new MinimumShouldMatch("50%"))
.Query(keyword)
))
.Highlight(h => h
.PreTags("<span style='color:red;'>")
.PostTags("</span>")
.FragmentSize(100)
.NoMatchSize(150)
.Fields(
fs => fs
.Field(p => p.Title),
fs => fs
.Field(p => p.Company),
fs => fs
.Field(p => p.Content)
)
)
);
var hits = searchResponse.HitsMetadata.Hits;
var total = searchResponse.Total;
foreach (var hit in hits)
{
foreach (var highlightField in hit.Highlight)
{
if (highlightField.Key == "title")
{
foreach (var highlight in highlightField.Value)
{
hit.Source.Title = highlight.ToString();
}
}
if (highlightField.Key == "content")
{
foreach (var highlight in highlightField.Value)
{
hit.Source.Content = highlight.ToString();
}
}
if (highlightField.Key == "company")
{
foreach (var highlight in highlightField.Value)
{
hit.Source.Company = highlight.ToString();
}
}
}
}
var hitsJson = Newtonsoft.Json.JsonConvert.SerializeObject(hits);
List<Article> list = new List<Article>();
foreach (var item in hits)
{
list.Add(item.Source);
}
Dictionary<string, object> result = new Dictionary<string, object>();
result.Add("list", list);
result.Add("total", total);
return result;
}
catch (Exception ex)
{
throw;
}
}
/// <summary>
/// 全文检索
/// </summary>
/// <param name="page"></param>
/// <param name="keyword"></param>
/// <returns></returns>
[HttpGet, Route("search")]
public IHttpActionResult Search(int? page,string keyword)
{
int pageIndex = page ?? 1;
return Ok(ESHelper.Search(pageIndex, keyword));
}
ESHelper.cs代码
public class ESHelper
{
private static ConnectionSettings settings = new ConnectionSettings(new Uri("http://localhost:9200")).DefaultIndex("articles");
private static ElasticClient client = new ElasticClient(settings);
/// <summary>
/// 获取client
/// </summary>
/// <returns></returns>
public static ElasticClient GetClient()
{
return client;
}
/// <summary>
/// 创建映射
/// </summary>
/// <returns></returns>
public static bool CreateMapping()
{
try
{
//映射
CreateIndexResponse createIndexResponse = client.Indices.Create("articles", c => c.Map<Article>(m => m.AutoMap()));
return true;
}
catch (Exception ex)
{
return false;
}
}
/// <summary>
/// 创建单个文档
/// </summary>
/// <param name="client"></param>
/// <param name="article"></param>
/// <returns></returns>
public static dynamic CreateArticle(Article article)
{
var indexResponse = client.IndexDocument<Article>(article);
return new { flag = true, msg = "操作成功" };
}
/// <summary>
/// 批量新增
/// </summary>
/// <param name="client"></param>
/// <param name="list"></param>
/// <returns></returns>
public static dynamic CreateBulk(List<Article> list)
{
var bulkAllObservable = client.BulkAll(list, b => b
.Index("articles")
.BackOffTime("30s")
.BackOffRetries(2)
.RefreshOnCompleted()
.MaxDegreeOfParallelism(Environment.ProcessorCount)
.Size(1000)
)
.Wait(TimeSpan.FromMinutes(15), next =>
{
// do something e.g. write number of pages to console
});
return new { flag = true, msg = "操作成功" };
}
/// <summary>
/// 根据id查询
/// </summary>
/// <param name="ids"></param>
/// <returns></returns>
public static List<Article> GetByIds(List<long> ids)
{
var searchResponse = client.Search<Article>(s => s.Query(q => q.Ids(m => m.Values(ids))));
return searchResponse.Documents.ToList();
}
/// <summary>
/// 批量删除
/// </summary>
/// <param name="client"></param>
/// <param name="list"></param>
/// <returns></returns>
public static dynamic DeleteBulk(List<Article> list)
{
var bulkResponse = client.DeleteMany(list);
return new { flag = true, msg = "操作成功" };
}
/// <summary>
/// 全文检索
/// </summary>
/// <param name="page"></param>
/// <param name="keyword"></param>
/// <returns></returns>
public static Dictionary<string, object> Search(int page, string keyword)
{
try
{
int size = 10;
int from = (page - 1) * size;
var searchResponse = client.Search<Article>(s => s
.From(from)
.Size(size)
.Query(q =>
q.MultiMatch(c => c
.Fields(f => f.Field(a => a.Title, 10).Field(a => a.Content).Field(a => a.Company, 10))
.Operator(Operator.Or)//只要有一个词在文档中出现都可以
.MinimumShouldMatch(new MinimumShouldMatch("50%"))
.Query(keyword)
))
.Highlight(h => h
.PreTags("<span style='color:red;'>")
.PostTags("</span>")
.FragmentSize(100)
.NoMatchSize(150)
.Fields(
fs => fs
.Field(p => p.Title),
fs => fs
.Field(p => p.Company),
fs => fs
.Field(p => p.Content)
)
)
);
var hits = searchResponse.HitsMetadata.Hits;
var total = searchResponse.Total;
foreach (var hit in hits)
{
foreach (var highlightField in hit.Highlight)
{
if (highlightField.Key == "title")
{
foreach (var highlight in highlightField.Value)
{
hit.Source.Title = highlight.ToString();
}
}
if (highlightField.Key == "content")
{
foreach (var highlight in highlightField.Value)
{
hit.Source.Content = highlight.ToString();
}
}
if (highlightField.Key == "company")
{
foreach (var highlight in highlightField.Value)
{
hit.Source.Company = highlight.ToString();
}
}
}
}
var hitsJson = Newtonsoft.Json.JsonConvert.SerializeObject(hits);
List<Article> list = new List<Article>();
foreach (var item in hits)
{
list.Add(item.Source);
}
Dictionary<string, object> result = new Dictionary<string, object>();
result.Add("list", list);
result.Add("total", total);
return result;
}
catch (Exception ex)
{
throw;
}
}
}
[ElasticsearchType(RelationName = "articles")]
public class Article
{
/// <summary>
/// id
/// </summary>
[Number]
public long Id { get; set; }
/// <summary>
/// 标题
/// </summary>
[Text(Analyzer = "ik_max_word", Index = true)]
public string Title { get; set; }
/// <summary>
/// 类型 新闻还是招聘
/// </summary>
[Keyword]
public string Type { get; set; }
/// <summary>
/// 内容
/// </summary>
[Text(Analyzer = "ik_max_word", Index = true)]
public string Content { get; set; }
/// <summary>
/// 新闻作者
/// </summary>
[Keyword]
public string Author { get; set; }
/// <summary>
/// 招聘公司
/// </summary>
[Text(Analyzer = "ik_max_word", Index = true)]
public string Company { get; set; }
/// <summary>
/// 招聘公司地址
/// </summary>
[Text(Analyzer = "ik_max_word", Index = true)]
public string CompanyAddress { get; set; }
/// <summary>
/// 创建时间
/// </summary>
[Date]
public DateTime CreateTime { get; set; }
/// <summary>
/// 访问路径
/// </summary>
[Keyword]
public string WebPath { get; set; }
}
ESController.cs代码
[RoutePrefix("api/es")]
public class ESController : ApiController
{
/// <summary>
/// 创建映射
/// </summary>
/// <returns></returns>
[HttpPost, Route("mapping")]
public IHttpActionResult Mapping()
{
return Ok(ESHelper.CreateMapping());
}
/// <summary>
/// 添加一个文档
/// </summary>
/// <param name="article"></param>
/// <returns></returns>
[HttpPost, Route("add")]
public IHttpActionResult Add(Article article)
{
return Ok(ESHelper.CreateArticle(article));
}
/// <summary>
/// 批量添加文档
/// </summary>
/// <param name="list"></param>
/// <returns></returns>
[HttpPost, Route("addBulk")]
public IHttpActionResult addBulk(List<Article> list)
{
return Ok(ESHelper.CreateBulk(list));
}
/// <summary>
/// 批量删除
/// </summary>
/// <param name="ids"></param>
/// <returns></returns>
[HttpPost, Route("delete")]
public IHttpActionResult Delete(List<long> ids)
{
//根据id获取list
var list = ESHelper.GetByIds(ids);
return Ok(ESHelper.DeleteBulk(list));
}
/// <summary>
/// 全文检索
/// </summary>
/// <param name="page"></param>
/// <param name="keyword"></param>
/// <returns></returns>
[HttpGet, Route("search")]
public IHttpActionResult Search(int? page,string keyword)
{
int pageIndex = page ?? 1;
return Ok(ESHelper.Search(pageIndex, keyword));
}
}