Elastisearch是一個(gè)很強(qiáng)大,易用的搜索引擎
在系統(tǒng)上運(yùn)行Elastisearch只需以下幾步

1.下載Elastisearch

wget https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-5.4.0.zip

2.解壓

unzip elasticsearch-5.4.0.zip

3.運(yùn)行

elasticsearch-5.4.0/bin/elasticsearch

這時(shí)有可能會(huì)直接被Killed掉瘦赫，因?yàn)閮?nèi)存溢出（OOM）赦肋，elastisearch占用的內(nèi)存非常大，所以在內(nèi)存比較小的服務(wù)器上運(yùn)行要先修改jvm的內(nèi)存大小

vi elasticsearch-5.4.0/config/jvm.options

將22和23行的棧堆大小改為512M

-Xms512M
-Xmx512M

如果重新啟動(dòng)后還是killed就再改小一點(diǎn)

4.測(cè)試是否成功

curl    'http://localhost:9200/?pretty'

你能看到以下返回信息:

{
            "status":   200,
            "name": "Shrunken   Bones",
            "version":  {
                        "number":   "1.4.0",
                        "lucene_version":   "4.10"
            },
            "tagline":  "You    Know,   for Search"
}

則表明啟動(dòng)成功

接下來(lái)我們用Java的API來(lái)操作Elasticsearch

首先是導(dǎo)入elastisearch和log4j的包

POM

<?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>

    <groupId>com.jk</groupId>
    <artifactId>ElasticsearchExample</artifactId>
    <version>1.0-SNAPSHOT</version>
    <dependencies>
        <dependency>
            <groupId>org.elasticsearch.client</groupId>
            <artifactId>transport</artifactId>
            <!--用哪個(gè)版本就填什么-->
            <version>5.4.0</version>
        </dependency>
        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-api</artifactId>
            <version>2.7</version>
        </dependency>
    </dependencies>

</project>

以下是常用的幾種操作

1.創(chuàng)建client

Client client = null;
        try {
            client = new PreBuiltTransportClient(Settings.EMPTY)
                    .addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName("localhost"), 9300));
        } catch (Exception e) {
            e.printStackTrace();
        }

2.創(chuàng)建索引

/**
     * 創(chuàng)建索引泰讽，有則先刪除
     * @param client
     */
    private static void recreateIndex(Client client) {
        if (client.admin().indices().prepareExists(index).execute().actionGet()
                .isExists()) {
            DeleteIndexResponse deleteIndexResponse = client.admin().indices()
                    .delete(new DeleteIndexRequest(index)).actionGet();
            System.out.println("delete index :");
            System.out.println(deleteIndexResponse);
        }

        CreateIndexResponse createIndexResponse = client.admin().indices()
                .prepareCreate(index).execute().actionGet();
        System.out.println("create index :");
        System.out.println(createIndexResponse);
    }

3.插入數(shù)據(jù)

/**
     * 插入數(shù)據(jù)
     * @param client
     */
    @SuppressWarnings({"rawtypes", "unchecked"})
    private static void doIndex(final Client client) {
        Map s11 = new LinkedHashMap();
        s11.put("title", "Think in java");
        s11.put("origin", "美國(guó)");
        s11.put("description", "初級(jí)java開(kāi)發(fā)人員必讀的書(shū)");
        s11.put("author", "Bruce Eckel");
        s11.put("price", 108);

        Map s12 = new LinkedHashMap();
        s12.put("title", "Head First Java");
        s12.put("origin", "英國(guó)");
        s12.put("description", "java入門(mén)教材");
        s12.put("author", "Kathy Sierra");
        s12.put("price", 54);

        Map s21 = new LinkedHashMap();
        s21.put("title", "Design Pattern");
        s21.put("origin", "法國(guó)");
        s21.put("description", "程序員不得不讀的設(shè)計(jì)模式");
        s21.put("author", "Kathy Sierra");
        s21.put("price", 89);

        Map s22 = new LinkedHashMap();
        s22.put("title", "黑客與畫(huà)家");
        s22.put("origin", "法國(guó)");
        s22.put("description", "讀完之后腦洞大開(kāi)");
        s22.put("author", "Paul Graham");
        s22.put("price", 35);

        BulkResponse bulkResponse = client
                .prepareBulk()
                .add(client.prepareIndex(index, type).setId("11").setSource(s11).setOpType(IndexRequest.OpType.INDEX).request())
                .add(client.prepareIndex(index, type).setId("12").setSource(s12).setOpType(IndexRequest.OpType.INDEX).request())
                .add(client.prepareIndex(index, type).setId("21").setSource(s21).setOpType(IndexRequest.OpType.INDEX).request())
                .add(client.prepareIndex(index, type).setId("22").setSource(s22).setOpType(IndexRequest.OpType.INDEX).request())
                .execute().actionGet();
        if (bulkResponse.hasFailures()) {
            System.err.println("index docs ERROR:" + bulkResponse.buildFailureMessage());
        } else {
            System.out.println("index docs SUCCESS:");
            System.out.println(bulkResponse);
        }
    }

4.查詢所有

    /**
     * 查詢所有
     */
    private static void searchAll(Client client) {
        SearchResponse response = client.prepareSearch(index)
                .setQuery(QueryBuilders.matchAllQuery())
                .setExplain(true).execute().actionGet();
        System.out.println("searchAll : ");
        for (SearchHit searchHit : response.getHits()) {
            System.out.println("********");
            System.out.println(searchHit.getSource());
        }
    }

5.關(guān)鍵詞查詢

    /**
     * 關(guān)鍵詞查詢
     *
     * @param client
     */
    private static void searchKeyWord(Client client) {
        SearchResponse response = client.prepareSearch(index)
                //查詢所有字段匹配關(guān)鍵字
                .setQuery(QueryBuilders.matchQuery("_all", "法國(guó)"))
                //設(shè)置最小匹配程度
//                .setQuery(QueryBuilders.matchQuery("_all", "法國(guó)").minimumShouldMatch("100%"))
                .execute().actionGet();
        System.out.println("searchKeyWord : ");
        System.out.println(response);
    }

6.數(shù)值范圍過(guò)濾

    /**
     * 數(shù)值范圍過(guò)濾
     *
     * @param client
     */
    private static void searchRange(Client client) {
        SearchResponse response = client.prepareSearch(index).
                //大于80抢韭，小于100
                setQuery(QueryBuilders.rangeQuery("price").gt(80).lt(100))
                .execute()
                .actionGet();
        System.out.println("searchRange : ");
        System.out.println(response);
    }

7.排序

    /**
     * 排序
     *
     * @param client
     */
    private static void searchOrdered(Client client) {
        SearchResponse response = client.prepareSearch(index)
                .setQuery(QueryBuilders.matchAllQuery())
                //根據(jù)價(jià)格降序排序
                .addSort(SortBuilders.fieldSort("price")
                        .order(SortOrder.DESC)).execute().actionGet();
        System.out.println("searchOrdered : ");
        System.out.println(response);
    }

8.高亮關(guān)鍵字

/**
     * 高亮關(guān)鍵字
     * @param client
     */
    private static void searchHightlight(Client client) {
        //高亮多個(gè)字段
        HighlightBuilder highlightBuilder = new HighlightBuilder();
        highlightBuilder.field("title");
        highlightBuilder.field("description");
        SearchResponse response = client.prepareSearch(index)
                //單條件匹配薪贫，高亮?xí)r只能高亮該字段
//                .setQuery(QueryBuilders.matchQuery("title", "java"))
                //多條件匹配，高亮?xí)r只能高亮多個(gè)字段
                .setQuery(QueryBuilders.multiMatchQuery("開(kāi)發(fā)人員必讀", "title", "description"))
                .highlighter(highlightBuilder)
                .execute()
                .actionGet();
        System.out.println("searchHightlight : ");
        System.out.println(response);
    }

9.根據(jù)id查找

    /**
     * 根據(jù)id查找
     * @param client
     */
    private static void findById(final Client client) {
        String id="12";
        GetResponse response = client.prepareGet(index, type, id).get();
        System.out.println("findById");
        System.out.println(response);
    }

10.刪除

     /**
     * 刪除
     * @param client
     */
    private static void deleteById(Client client) {
        String id="12";
        DeleteResponse response = client.prepareDelete(index, type, id).get();
    }

11.更新

    /**
     * 更新
     * @param client
     */
    private static void updateById(Client client) {
        try {
            String id="11";
            client.prepareUpdate(index, type, id)
                    .setDoc(jsonBuilder()
                            .startObject()
                            .field("title", "白鹿原")
                            .endObject())
                    .get();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

常用的操作就這些,代碼上傳到https://github.com/jkgeekJack/ElasticsearchExample

建議大家還可以看看Elasticsearch: 權(quán)威指南,這里有更詳細(xì)的介紹