kotlin + springboot启用elasticsearch搜索

参考自：

http://how2j.cn/k/search-engine/search-engine-springboot/1791.html?p=78908

工具版本： elasticsearch 6.2.2、 kibana 6.2.2，  下载地址： elasticsearch、kibana

下载demo

1、kotlin版springboot项目创建

访问https://start.spring.io/， 创建项目demo（maven + kotlin + springboot 2.1.7， 其他默认）。

添加web支持、elasticsearch搜索及kotlin测试所需依赖

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-data-elasticsearch -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-elasticsearch</artifactId>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.jetbrains.kotlin/kotlin-test-junit5 -->
        <dependency>
            <groupId>org.jetbrains.kotlin</groupId>
            <artifactId>kotlin-test-junit5</artifactId>
            <version>1.2.70</version>
            <scope>test</scope>
        </dependency>

最终pom.xml文件为

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.7.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>demo</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
        <kotlin.version>1.2.71</kotlin.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>org.jetbrains.kotlin</groupId>
            <artifactId>kotlin-reflect</artifactId>
        </dependency>
        <dependency>
            <groupId>org.jetbrains.kotlin</groupId>
            <artifactId>kotlin-stdlib-jdk8</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-data-elasticsearch -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-elasticsearch</artifactId>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.jetbrains.kotlin/kotlin-test-junit5 -->
        <dependency>
            <groupId>org.jetbrains.kotlin</groupId>
            <artifactId>kotlin-test-junit5</artifactId>
            <version>1.2.70</version>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <sourceDirectory>${project.basedir}/src/main/kotlin</sourceDirectory>
        <testSourceDirectory>${project.basedir}/src/test/kotlin</testSourceDirectory>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
            <plugin>
                <groupId>org.jetbrains.kotlin</groupId>
                <artifactId>kotlin-maven-plugin</artifactId>
                <configuration>
                    <args>
                        <arg>-Xjsr305=strict</arg>
                    </args>
                    <compilerPlugins>
                        <plugin>spring</plugin>
                    </compilerPlugins>
                </configuration>
                <dependencies>
                    <dependency>
                        <groupId>org.jetbrains.kotlin</groupId>
                        <artifactId>kotlin-maven-allopen</artifactId>
                        <version>${kotlin.version}</version>
                    </dependency>
                </dependencies>
            </plugin>
        </plugins>
    </build>

</project>

2、创建实体类Category.kt

package com.example.demo.entity

import org.springframework.data.elasticsearch.annotations.Document

@Document(indexName = "test", type = "category")
class Category {
    var id : Int? = null;
    var name : String? = null;
}

es操作dao类CategoryESDAO.kt

package com.example.demo.es

import com.example.demo.entity.Category
import org.springframework.data.elasticsearch.repository.ElasticsearchRepository

interface CategoryESDAO : ElasticsearchRepository<Category, Int>

创建类SearchController.kt，并实现搜索方法，这里根据keyword作为前缀进行搜索

package com.example.demo.controller

import com.example.demo.entity.Category
import com.example.demo.es.CategoryESDAO
import org.elasticsearch.common.lucene.search.function.FunctionScoreQuery
import org.elasticsearch.index.query.QueryBuilders
import org.elasticsearch.index.query.functionscore.ScoreFunctionBuilders
import org.springframework.data.domain.PageRequest
import org.springframework.data.domain.Sort
import org.springframework.data.elasticsearch.core.query.NativeSearchQueryBuilder
import org.springframework.stereotype.Controller
import org.springframework.web.bind.annotation.GetMapping
import org.springframework.web.bind.annotation.RequestParam
import org.springframework.web.bind.annotation.RestController
import javax.annotation.Resource

@RestController
class SearchController {

    @Resource
    private lateinit var categoryESDAO: CategoryESDAO

    @GetMapping("/search")
    fun search(@RequestParam(value = "keyword") keyword: String, @RequestParam(value = "start", defaultValue = "0") start: Int,
               @RequestParam(value = "size", defaultValue = "5") size: Int): List<Category> {
        val queryBuilder = QueryBuilders.matchPhrasePrefixQuery("name", keyword)
        val sort = Sort(Sort.Direction.DESC, "id")
        val pageable = PageRequest.of(start, size, sort)
        val searchQuery = NativeSearchQueryBuilder()
                .withPageable(pageable)
                .withQuery(queryBuilder).build()
        val page = categoryESDAO.search(searchQuery)

        return page.content.filter {category ->  category != null}.toList()
    }

}

在类DemoApplication.kt中指定包名，

package com.example.demo

import org.springframework.boot.autoconfigure.SpringBootApplication
import org.springframework.boot.runApplication
import org.springframework.data.elasticsearch.repository.config.EnableElasticsearchRepositories

@SpringBootApplication
@EnableElasticsearchRepositories(basePackages = ["com.example.demo.es"])
class DemoApplication

fun main(args: Array<String>) {
    runApplication<DemoApplication>(*args)
}

在resources目录下application.properties中增加elasticsearch的参数

#ElasticSearch
spring.data.elasticsearch.cluster-nodes = 127.0.0.1:9300

3、创建测试类

在test/kotlin目录下com.example.demo包下创建类TestSearchController.kt测试搜索

package com.example.demo

import com.example.demo.entity.Category
import com.example.demo.es.CategoryESDAO
import org.junit.jupiter.api.BeforeAll
import org.junit.jupiter.api.BeforeEach
import org.junit.jupiter.api.Test
import org.junit.jupiter.api.TestInstance
import org.springframework.boot.test.context.SpringBootTest
import org.springframework.http.HttpMethod
import org.springframework.test.context.web.WebAppConfiguration
import org.springframework.test.web.servlet.request.MockMvcRequestBuilders
import org.springframework.test.web.servlet.result.MockMvcResultMatchers
import org.springframework.test.web.servlet.setup.MockMvcBuilders
import org.springframework.web.context.WebApplicationContext
import javax.annotation.Resource

@SpringBootTest
@WebAppConfiguration
class TestSearchController {

    @Resource
    private lateinit var wac : WebApplicationContext

    @Resource
    private lateinit var categoryESDAO: CategoryESDAO

    @BeforeEach
    fun add() {
        for (ch in 'a'..'z') {
            val category = Category()
            category.id = ch - 'a'
            category.name = ch.toUpperCase().toString().plus(ch)
            categoryESDAO.save(category)
        }
    }

    @Test
    fun test() {
        val mockMvc = MockMvcBuilders.webAppContextSetup(wac).build()
        val result = mockMvc.perform(MockMvcRequestBuilders.request(HttpMethod.GET, "/search?keyword=Aa"))
                .andExpect(MockMvcResultMatchers.status().isOk)
                .andDo(::println)
                .andReturn().response.contentAsString;
        println(result)
    }
}

依次启动elasticsearch6.2.2、kibana6.2.2，

在浏览器中打开http://localhost:5601/app/kibana#/dev_tools/console?_g=()

执行

PUT test

创建test（对应Category类Document注解 indexName）索引，然后执行TestSearchController类进行测试，

控制台输出结果为：

[{"id":0,"name":"Aa"}]