spring-boot学习笔记（三）ElasticSearch介绍与项目集成
一、ElasticSearch介绍
分布式高可用，例如将一个系统部署在一台服务器上面，某一天崩溃了，该系统就无法使用了，但是当分布式部署到多台服务器上面之后，其中几个服务器崩溃掉了，但是不会影响整体的运作，从而实现高可用。
二、ElasticSearch项目集成
1、build.gradle添加es依赖和jna依赖，application.properties配置文件添加es服务地址和连接超时时间
dependencies {
compile('org.springframework.boot:spring-boot-starter-web')
compile('org.springframework.boot:spring-boot-starter-thymeleaf')
compile('org.springframework.boot:spring-boot-starter-data-jpa')
compile('org.springframework.boot:spring-boot-starter-data-elasticsearch')
runtime('com.h2database:h2:1.4.196')
testCompile('org.springframework.boot:spring-boot-starter-test')
compile('mysql:mysql-connector-java:6.0.5')
compile('net.java.dev.jna:jna:4.5.1')
}#elasticSearch服务地址
spring.data.elasticsearch.cluster-nodes=localhost:9300
#设置连接超时时间
spring.data.elasticsearch.properties.transport.tcp.connect_timeout=120s2、下载elasticsearch-6.3.0，解压到d:盘下，打开D:\elasticsearch-6.3.0\bin ，点击elasticsearch.bat 启动es服务，
访问本地9200端口，看到es版本信息说明启动成功。
3、编写测试用例
新建EsBlog实体类
*/
@Document(indexName="blog",type="blog")
public class EsBlog implements Serializable {
/**
*
*/
private static final long serialVersionUID = 159383211493905568L;
@Id
private String id;
private String title;
private String summary;
private String content;编写接口继承ElasticsearchRepository
public interface EsBlogRepository extends ElasticsearchRepository {
/**
* 分页查询博客去重
* @param title
* @param summary
* @param content
* @param pageable
* @return Page
*/
Page findDistinctEsBlogByTitleContainingOrSummaryContainingOrContentContaining(String title,String summary,String content,Pageable pageable);
} 编写测试test代码
@RunWith(SpringRunner.class)
@SpringBootTest
public class EsBlogRepositoryTest {
@Autowired
private EsBlogRepository esBlogRepository;
public void initRepositoryData() {
/**
* 删除所有数据
*/
esBlogRepository.deleteAll();
/**
* 初始化三个blog
*/
esBlogRepository.save(new EsBlog("1", "段", "段朝旭"));
esBlogRepository.save(new EsBlog("2", "朝", "段朝旭"));
esBlogRepository.save(new EsBlog("3", "旭", "段朝旭"));
}
/**
* 分页查询博客去重
*
* @param title
* @param summary
* @param content
* @param pageable
* @return Page
*/
@Test
public void findDistinctEsBlogByTitleContaingOrSummaryContaingOrContentContaing() {
initRepositoryData();
Pageable pageable = PageRequest.of(0, 20);
Page page = esBlogRepository
.findDistinctEsBlogByTitleContainingOrSummaryContainingOrContentContaining("1", "旭", "王", pageable);
System.out.println(page.getTotalElements());
for (EsBlog blog : page.getContent()) {
System.out.println(blog);
}
} 运行测试代码之后看到控制台打印出
说明执行成功。
4、编写controller层
@RestController
@RequestMapping("/blog")
public class EsBlogController {
@Autowired
private EsBlogRepository esBlogRepository;
@GetMapping
public List list(@RequestParam(value="title")String title,
@RequestParam(value="summary")String summary,
@RequestParam(value="content")String content,
@RequestParam(value="pageIndex",defaultValue="0")int pageIndex,
@RequestParam(value="pageSize",defaultValue="10")int pageSize){
Pageable pageable = PageRequest.of(pageIndex,pageSize);
Page page = esBlogRepository.findDistinctEsBlogByTitleContainingOrSummaryContainingOrContentContaining(title,summary,content,pageable);
return page.getContent();
}
} 访问如图所示的地址，可看到返回的json格式数据
