ElasticSearch(二)

Elasticsearch

使用原生API操作elasticsearch

在pom.xml中导入坐标
<properties>
    <maven.compiler.target>1.9</maven.compiler.target>
    <maven.compiler.source>1.9</maven.compiler.source>
</properties>
<dependencies>
    <dependency>
        <groupId>org.elasticsearch</groupId>
        <artifactId>elasticsearch</artifactId>
        <version>5.6.8</version>
    </dependency>
    <dependency>
        <groupId>org.elasticsearch.client</groupId>
        <artifactId>transport</artifactId>
        <version>5.6.8</version>
    </dependency>
    <dependency>
        <groupId>org.apache.logging.log4j</groupId>
        <artifactId>log4j-to-slf4j</artifactId>
        <version>2.9.1</version>
    </dependency>
    <dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>slf4j-api</artifactId>
        <version>1.7.24</version>
    </dependency>
    <dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>slf4j-simple</artifactId>
        <version>1.7.21</version>
    </dependency>
    <dependency>
        <groupId>log4j</groupId>
        <artifactId>log4j</artifactId>
        <version>1.2.12</version>
    </dependency>
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.12</version>
    </dependency>
      <!--jackson依赖-->
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-databind</artifactId>
        <version>2.8.1</version>
    </dependency>
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-annotations</artifactId>
        <version>2.8.1</version>
    </dependency>
</dependencies>

创建索引库index

@Test
public void testCreateIndex()throws UnknownHostException{
	//创建Settings对象,相当于配置信息
	Settings settings = Settings.builder().put("cluster.name","elasticsearch").build();
	//创建TrasnportClient对象,TransportClient是一个abstract类
	TransportClient client = new PreBuiltTransportClient(settings);
	//指定本机IP地址,Inet协议端口号
	client.addTransportAddress(
new InetSocketTransportAddress(InetAddress.getByName("127.0.0.1"),9300));
	//创建索引库
	client.admin().indices().prepareCreate("blog").get();
	//释放资源
	client.close();
}

创建索引库后设置mapping

@Test
public void testSetMapping(){
	//创建Settings对象,相当于配置信息
	Settings settings = Settings.builder().put("cluster.name","elasticsearch").build();
	//创建TrasnportClient对象
	TransportClient client = new PreBuiltTransportClient(settings);
	//指定本机IP地址,Inet协议端口号
	client.addTransportAddress(
new InetSocketTransportAddress(InetAddress.getByName("127.0.0.1"),9300));
	//获取XContentBuilder对象
	XContentBuilder builder = XContentFactory.jsonBuilder()
		.startObject()
			.startObject("article")		
				.startObject("properties")
					.startObject("id")
						.field("type","long")
						.field("store",true)
						.field("index",true)
					.endObject()
					.startObject("title")
						.field("type","text")
						.field("store",true)
						.field("index",true)
						.field("analyzer","ik_smart")
					.endObject()
					.startObject("content")
						.field("type","text")
						.field("store",true)
						.field("index",true)
						.field("analyzer","ik_smart")	
					.endObject()
				.endObject()
			.endObject()
		.endObject();
//获取PutMappingRequest对象
PutMappingRequest mapping = Requests.putRequestMapping("blog")
		.type("article")
		.source(builder);
//执行设置mapping
client.admin().indices().putMapping(mapping).get();
//释放资源
client.close();
}

抽取获得Client对象和释放资源的方法

private TransportClient client;
@Before
public void init(){
	Settings settings = Settings.builder().put("cluster.name","elasticsearch").build();
	client = new PreBuiltTransportClient(settings);
	client.addTransportAddress(
new InetSocketTransportAddress(InetAddress.getByName("127.0.0.1"),9300));
}
@After
public void destroy(){
	client.close();
}

添加一条Document

<!--使用XContentBuilder来保存一条Document-->
@Test
public void testSaveDocumentByXContentBuilder(){
	//获取XContentBuilder对象
	XContentBuilder builder = XContentFactory.jsonBuilder()
		.startObject()
			.field("id",1l)
			.field("title","test title one")
			.field("content","test content one")
		.endObject();
	//执行添加操作
	client.prepareIndex("blog","article","1").setSource(builder).get();
}
<!--使用Jackson转换实体类数据后保存-->
public class Article{
	private long id;	
	private String title;
	private String content;
}
@Test
public void testSaveDocumentByJackson(){
	//创建Article对象
	Article article = new Article(2l,"test title two","test content two");
	//将article对象转换为json字符串
	String articleStr = new ObjectMapper().writeValueAsString(article);
	//执行添加操作
	client.prepareIndex("blog","article",article.getId().toString())
.setSource(articleStr,XContentType.JSON).get();
}

查询Documents

1.根据文档ID查询
@Test
public void testFindById(){
	//创建QueryBuilder对象
	QueryBuilder builder = QueryBuilders.idsQuery().addIds("1","2");
	search(builder);
}
2.根据关键词(Term)查询
@Test
public void testFindByTerm(){
	//创建QueryBuilder对象
	QueryBuilder builder = QueryBuilders.termQuery("content","test");
	search(builder);
}
3.根据QueryString(分词)查询
@Test
public void testFindByString(){
	//创建QueryBuilder对象
QueryBuilder builder = QueryBuilders.queryStringQuery("content","test").defaultField("content");
	search(builder);
}
 
private void search(QueryBuilder builder){
	//获取SearchResponse对象
	SearchResponse search = client.prepareSearch("blog")
								.setTypes("article")
								.setQuery(builder)
								.get();
	//获取SearchHits对象
	SearchHits searchHits = search.getHits();
	System.out.println("总记录数:"+searchHits.getTotalHits());
	//迭代searchHits集合
	Iterator<SearchHit> it = searchHits.iterator();
     while(it.hasNext()){
        String document = it.next().getSourceAsString();
    }
}

分页查询

	SearchResponse search = SearchResponse.prepareSearch("blog")
								.setType("article")
								.setQuery(builder)	
								.setFrom(0)		//from：设置起始的行号,从0开始
								.setSize(15)	//size：设置每页显示的记录数,默认是10条记录
								.get();

Highlight Show

	//创建HighlightBuilder对象
    HighlightBuilder highlightBuilder = new HighlightBuilder();
    highlightBuilder.preTags("<font style='color:red'>");	//设置关键字的前缀
    highlightBuilder.postTags("</fontfont>");		//设置关键字的后缀
    highlightBuilder.field("title");		 //设置高亮显示的域
SearchResponse search = SearchResponse.prepareSearch("blog")
								.setType("article")
								.setQuery(builder)	
								.setFrom(0)		 
								.setSize(15)
								.highlighter(highlightBuilder)
								.get();
	Iterator<SearchHit> it = searchHits.iterator();
     while(it.hasNext()){
        SearchHit searchHit = it.next();
        System.out.println("String方式打印文档搜索内容:");
        System.out.println(searchHit.getSourceAsString());
        System.out.println("Map方式打印高亮内容");
        System.out.println(searchHit.getHighlightFields());
        System.out.println("遍历高亮集合，打印高亮片段:");
        Text[] text = searchHit.getHighlightFields().get("title").getFragments();
        for (Text str : text) {
            System.out.println(str);
        }
    }