Spring Boot整合Elasticsearch

安装elasticsearch

1. 下载

下载：https://www.elastic.co/cn/downloads/elasticsearch

版本：我使用的是最新版（7.4.2）

2. 在Linux下安装&启动

创建elasticsearch用户和组

groupadd es
useradd es -g es -p es

解压

tar -zxvf elasticsearch-7.4.2-linux-x86_64.tar.gz -C /home/es/

进入解压后的目录，给es用户授权

cd /home/es/

chown -R es:es elasticsearch-7.4.2/

修改默认jvm内存大小，因为是测试，不需要很大，所以适当修改就好，不修改如果你的机器内存不够会抛出一个错误：

Java HotSpot(TM) 64-Bit Server VM warning: INFO: os::commit_memory(0x00000000c5330000, 986513408, 0) failed; error='Cannot allocate memory' (errno=12)

修改默jvm配置

cd elasticsearch-7.4.2/config/

vim jvm.options

# 修改如下配置
-Xms256m
-Xmx512m

启动

cd ../

# 切换为es用户
su es

bin/elasticsearch

启动的时候会有这样一个提示：意思就是后续将支持Java11，不过也可以正常启动

future versions of Elasticsearch will require Java 11; your Java version from [/usr/local/jdk/jre] does not meet this requirement

访问

# 使用curl访问
curl http://localhost:9200

{
  "name" : "VM_80_178_centos",
  "cluster_name" : "elasticsearch",
  "cluster_uuid" : "mKL-m0knTVS8N78rRdvEEQ",
  "version" : {
    "number" : "7.4.2",
    "build_flavor" : "default",
    "build_type" : "tar",
    "build_hash" : "2f90bbf7b93631e52bafb59b3b049cb44ec25e96",
    "build_date" : "2019-10-28T20:40:44.881551Z",
    "build_snapshot" : false,
    "lucene_version" : "8.2.0",
    "minimum_wire_compatibility_version" : "6.8.0",
    "minimum_index_compatibility_version" : "6.0.0-beta1"
  },
  "tagline" : "You Know, for Search"
}

外网访问

在config下elasticsearch.yml中新增如下配置，重启即可：

network.host: 0.0.0.0

# 更改为开发模式
discovery.type: single-node

安装可视化插件

需要安装nodejs和npm，至于怎么安装百度吧，安装完成后，访问http://ip:9100

git clone https://github.com/mobz/elasticsearch-head.git

cd elasticsearch-head

npm install

Spring Boot整合elasticsearch

初始化一个SpringBoot项目

依赖如下

<?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>2.2.1.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.dbnewyouth</groupId>
    <artifactId>springboot-elasticsearh</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>springboot-elasticsearh</name>
    <description>springboot-elasticsearh</description>

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

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

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
        </dependency>

    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
        <resources>
            <resource>
                <directory>src/main/java</directory>
                <includes>
                    <include>**/*.properties</include>
                    <include>**/*.xml</include>
                </includes>
                <filtering>true</filtering>
            </resource>
            <resource>
                <directory>src/main/resources</directory>
                <filtering>true</filtering>
            </resource>
        </resources>
    </build>

</project>

配置文件application.yaml

server:
  port: 8080

spring:
  data:
    elasticsearch:
      # 9200是http的端口，9300是java调用的端口

      cluster-nodes: 123.207.253.50:9300
      cluster-name: elasticsearch
      local: false
      repositories:
        enabled: true

新建User实体类

需要注意，indexName和type的值必须小写！

@Document(indexName = "userindex", type = "user")
public class User implements Serializable {

    private static final long serialVersionUID = 1L;

    private Long id;
    private String name;
    private Integer age;
    private String sex;
    private String address;
    private String description;
    private Date createTime;

    // Getter和Setter方法省略

}

新建dao接口，继承ElasticsearchRepository

public interface UserDao extends ElasticsearchRepository<User, Long> {
}

新建业务层IUserService接口和实现类UserServiceImpl

新建IUserService接口

public interface IUserService {    public boolean insert(User user);    public List search(String searchContent);}

新建UserServiceImpl实现类

@Service("userService")
public class UserServiceImpl implements IUserService {

    @Autowired
    private UserDao userDao;

    @Override
    public boolean insert(User user) {
        try {
            userDao.save(user);
            return true;
        }catch (Exception e){
            e.printStackTrace();
        }
        return false;
    }

    @Override
    public List<User> search(String searchContent) {
        QueryStringQueryBuilder builder = new QueryStringQueryBuilder(searchContent);
        Iterable<User> search = userDao.search(builder);
        if(search == null){
            return null;
        }
        Iterator<User> iterator = search.iterator();
        List<User> list = new ArrayList<>();
        while (iterator.hasNext()){
            list.add(iterator.next());
        }
        return list;
    }
}

新建Result统一返回类，为了方便统一返回结果

public class Result implements Serializable {

    private static final long serialVersionUID = 1L;

    private Integer code;
    private String message;
    private Object data;

    public Result(Integer code, String message) {
        this.code = code;
        this.message = message;
    }

    public Result(Integer code, String message, Object data) {
        this.code = code;
        this.message = message;
        this.data = data;
    }

    // Getter和Setter方法省略

}

新建UserController类

@RestController
@RequestMapping("/user")
public class UserController {

    @Autowired
    private IUserService userService;

    @PostMapping("/insert")
    public Result insert(User user) {
        if(user == null){
            return new Result(-1, "参数不能为空");
        }
        if(StringUtils.isEmpty(user.getName())){
            return new Result(-1, "姓名不能为空");
        }
        user.setCreateTime(new Date());
        boolean insertStatus = userService.insert(user);
        if(insertStatus){
            return new Result(200, "插入成功");
        }
        return new Result(-1, "插入失败");
    }

    @GetMapping("/search")
    public Result search(String searchContent){
        List<User> list = userService.search(searchContent);
        return new Result(200, "查询成功", list);
    }
}