Java使用强大的Elastisearch搜索引擎实例代码

elastisearch是一个很强大,易用的搜索引擎

在系统上运行elastisearch只需以下几步

1.下载elastisearch

wget

2.解压

unzip elasticsearch-5.4.0.zip

3.运行

elasticsearch-5.4.0/bin/elasticsearch

这时有可能会直接被killed掉，因为内存溢出（oom），elastisearch占用的内存非常大，所以在内存比较小的服务器上运行要先修改jvm的内存大小

vi elasticsearch-5.4.0/config/jvm.options

将22和23行的栈堆大小改为512m

-xms512m
-xmx512m

如果重新启动后还是killed就再改小一点

4.测试是否成功

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"
}

则表明启动成功

接下来我们用java的api来操作elasticsearch

首先是导入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>
      <!--用哪个版本就填什么-->
      <version>5.4.0</version>
    </dependency>
    <dependency>
      <groupid>org.apache.logging.log4j</groupid>
      <artifactid>log4j-api</artifactid>
      <version>2.7</version>
    </dependency>
  </dependencies>

</project>

以下是常用的几种操作

1.创建client

client client = null;
    try {
      client = new prebuilttransportclient(settings.empty)
          .addtransportaddress(new inetsockettransportaddress(inetaddress.getbyname("localhost"), 9300));
    } catch (exception e) {
      e.printstacktrace();
    }

2.创建索引

/**
   * 创建索引，有则先删除
   * @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.插入数据

/**
   * 插入数据
   * @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", "美国");
    s11.put("description", "初级java开发人员必读的书");
    s11.put("author", "bruce eckel");
    s11.put("price", 108);

    map s12 = new linkedhashmap();
    s12.put("title", "head first java");
    s12.put("origin", "英国");
    s12.put("description", "java入门教材");
    s12.put("author", "kathy sierra");
    s12.put("price", 54);

    map s21 = new linkedhashmap();
    s21.put("title", "design pattern");
    s21.put("origin", "法国");
    s21.put("description", "程序员不得不读的设计模式");
    s21.put("author", "kathy sierra");
    s21.put("price", 89);

    map s22 = new linkedhashmap();
    s22.put("title", "黑客与画家");
    s22.put("origin", "法国");
    s22.put("description", "读完之后脑洞大开");
    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.查询所有

  /**
   * 查询所有
   */
  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.关键词查询

  /**
   * 关键词查询
   *
   * @param client
   */
  private static void searchkeyword(client client) {
    searchresponse response = client.preparesearch(index)
        //查询所有字段匹配关键字
        .setquery(querybuilders.matchquery("_all", "法国"))
        //设置最小匹配程度
//        .setquery(querybuilders.matchquery("_all", "法国").minimumshouldmatch("100%"))
        .execute().actionget();
    system.out.println("searchkeyword : ");
    system.out.println(response);
  }

6.数值范围过滤

  /**
   * 数值范围过滤
   *
   * @param client
   */
  private static void searchrange(client client) {
    searchresponse response = client.preparesearch(index).
        //大于80，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())
        //根据价格降序排序
        .addsort(sortbuilders.fieldsort("price")
            .order(sortorder.desc)).execute().actionget();
    system.out.println("searchordered : ");
    system.out.println(response);
  }

8.高亮关键字

/**
   * 高亮关键字
   * @param client
   */
  private static void searchhightlight(client client) {
    //高亮多个字段
    highlightbuilder highlightbuilder = new highlightbuilder();
    highlightbuilder.field("title");
    highlightbuilder.field("description");
    searchresponse response = client.preparesearch(index)
        //单条件匹配，高亮时只能高亮该字段
//        .setquery(querybuilders.matchquery("title", "java"))
        //多条件匹配，高亮时只能高亮多个字段
        .setquery(querybuilders.multimatchquery("开发人员必读", "title", "description"))
        .highlighter(highlightbuilder)
        .execute()
        .actionget();
    system.out.println("searchhightlight : ");
    system.out.println(response);
  }

9.根据id查找

 /**
   * 根据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.删除

   /**
   * 删除
   * @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();
    }
  }

常用的操作就这些,代码上传到https://github.com/jkgeekjack/elasticsearchexample

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。