elasticSearch入门

最近在项目中遇到了需要搜索引擎的场景，对用户输入进行自动推荐和补全，elasticSearch是开源的搜索引引擎，入门使用也很简单。

怎么入门：

1. 类比入门：类比一个熟悉的知识点，知识迁移会更容易
2. 简单的事例入门：动手进行简单的一个demo感受一下流程

入门

1.安装es

前置条件：mac环境(其他环境自行google)，brew工具安装好了，java环境安装好了

步骤：

1. 安装es：
   • brew install elasticsearch
   • es服务端会被安装
2. 安装kibana：
   • brew install kibana
   • kibana可以理解为图形化的es客户端
3. 启动es：brew services start elasticsearch
4. 启动kibana：brew services start kibana

安装es成功之后访问http://localhost:9200/可以获得es的状态信息
安装kibana成功之后访问http://localhost:5601/app/kibana#/dev_tools/console?_g=()可以对es进行操作

2.自动补全

// hashtag
{
    id,
    name,
    score, // weight
}

mappings & analysizer

PUT feed_id
{
    "mappings": {
        "hashtag": {
            "properties": {
                "name": {
                    "type": "completion" 
                }
            }
        }
    }
}

添加数据

POST feed_id/hashtag
{
    "name": {
        "input": ["hashtag name"],
        "weight": 2
    }
}
POST feed_id/hashtag/3
{
    "name": {
        "input": ["hashtag name2"],
        "weight": 3
    }
}
POST feed_id/hashtag/4
{
    "name": {
        "input": ["ashtag name2"],
        "weight": 4
    }
}
POST feed_id/hashtag/5
{
    "name": {
        "input": ["shtag name2"],
        "weight": 5
    }
}
POST feed_id/hashtag/6
{
    "name": {
        "input": ["htag name2"],
        "weight": 6
    }
}
POST feed_id/hashtag/7
{
    "name": {
        "input": ["爱我中华"],
        "weight": 6
    }
}
POST feed_id/hashtag/8
{
    "name": {
        "input": ["爱你中华"],
        "weight": 6
    }
}
POST feed_id/hashtag/9
{
    "name": {
        "input": ["爱你"],
        "weight": 6
    }
}

查询数据

POST feed_id/_search?pretty
{
    "suggest": {
        "hashtag-suggest": {
            "prefix": "h",
            "completion": {
                "field": "name"
            }
        }
    }
}

基本概念

摘抄自elasticsearch-definitive-guide-cn

参考：