SpringBoot整合ES各种问题解决

一、No Available Nodes

问题原因：
1、可能是版本不兼容，例如我的 SpringBoot 版本是 2.1.8.RELEASE，那么对应的 ES 版本应该在 6.2.2 到 6.8.12 之间，这里选择了 ES:6.8.4 版本

版本对应表：https://docs.spring.io/spring-data/elasticsearch/docs/4.2.0/reference/html/#preface.requirements
2、在 elasticsearch.yml 中添加上配置

二、使用 ElasticsearchTemplate 提示找不到 Caused by: java.lang.ClassNotFoundException: org.elasticsearch.action.admin.indices.mapping.put.PutMappingResponse

按照知乎老哥的回答，应该将 pom.xml 中的 properties 中的 ES 相关版本去掉，这里我将填写的注释掉了，就好用了


附录-依赖信息：

<?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 https://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>2.1.8.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.lookstarry.doermail</groupId>
    <artifactId>doermail-search</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>doermail-search</name>
    <description>检索服务</description>
    <properties>
        <java.version>1.8</java.version>
<!--        <elasticsearch.version>7.4.2</elasticsearch.version>-->
<!--        <elasticsearch.version>6.8.4</elasticsearch.version>-->
    </properties>
    <dependencies>
        <dependency>
            <groupId>com.lookstarry.doermail</groupId>
            <artifactId>doermail-common</artifactId>
            <version>0.0.1-SNAPSHOT</version>
        </dependency>

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

        <!--<dependency>
            <groupId>org.elasticsearch.client</groupId>
            <artifactId>elasticsearch-rest-high-level-client</artifactId>
            <version>6.8.4</version>
        </dependency>-->

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

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

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>