Jest
ElasticSearch（ES） 是开源（apache 2 授权）、分布式、REST风格、搜索引擎基于Lucene的实现。
Jest是一个为ES操作Java Http Rest 的客户端，及使用它来捕获、存储以及操作数据。
Jest提供JavaAPI，可以很好的处理Java对象序列。通过Jest，可以获取普通的Java对象并在ES中为它们建立索引。然后使用ES的搜索API，将您的返回的对象转换Java对象。
可以通过Andrew Glover来阅读ES和Jest
安装说明
Jest Maven 托管在 Sonatype.
配置pom.xml 文件
<repositories> . . <repository> <id>sonatype</id> <name>Sonatype Groups</name> <url>https://oss.sonatype.org/content/groups/public/</url> </repository> . . </repositories>
添加依赖
<dependency> <groupId>io.searchbox</groupId> <artifactId>jest</artifactId> <version>0.0.3</version> </dependency>
更新日志 changelog
Jest 有一个简单的实例，请看这里 --->
使用Jest之前要需要一个JestClient
// Configuration
ClientConfig clientConfig = new ClientConfig();
LinkedHashSet<String> servers = new LinkedHashSet<String>();
servers.add("http://localhost:9200");
clientConfig.getProperties().put(ClientConstants.SERVER_LIST, servers);
clientConfig.getProperties().put(ClientConstants.IS_MULTI_THREADED, true);
// Construct a new Jest client according to configuration via factory
JestClientFactory factory = new JestClientFactory();
factory.setClientConfig(clientConfig);
JestClient client = factory.getObject();
JestClient使用单例模式，构造器是私有。
开始创建索引
通过Jest创建Index是一件很轻松的事
client.execute(new CreateIndex("articles"));
设置ES参数，可以通过JSON完成
String settings = "\"settings\" : {\n" +
" \"number_of_shards\" : 5,\n" +
" \"number_of_replicas\" : 1\n" +
" }\n";
client.execute(new CreateIndex("articles"), settings)
或者通过SetingsBuilder，添加ES依赖设置API
import org.elasticsearch.common.settings.ImmutableSettings;
.
.
ImmutableSettings.Builder settingsBuilder = ImmutableSettings.settingsBuilder();
settings.put("number_of_shards",5);
settings.put("number_of_replicas",1);
client.execute(new CreateIndex("articles"), settingsBuilder.build().getAsMap());
索引文档
ES请求索引数据JSON格式，通过Jest的几种方法创建文档索引
1.JSON 字符串
String source = "{\"user\":\"kimchy\"}";
2.ES JSONBuilder
String source = jsonBuilder()
.startObject()
.field("user", "kimchy")
.field("postDate", "date")
.field("message", "trying out Elastic Search")
.endObject().string();
3.Map
Map<String, String> source = new LinkedHashMap<String,String>()
source.put("user", "kimchy");
4.POJO
Article source = new Article();
source.setAuthor("John Ronald Reuel Tolkien");
source.setContent("The Lord of the Rings is an epic high fantasy novel");
指定索引数据生成索引 为twitter index with type tweet
Index index = new Index.Builder(source).index("twitter").type("tweet").build();
client.execute(index);
可以明确指定索引Id
Index index = new Index.Builder(source).index("twitter").type("tweet").id("1").build();
client.execute(index);
也可以通过Jest注解的方式指定索引Id
class Article {
@JestId
private Long documentId;
}
如果JestId 是null，则有ES自动生成Id。
搜索文档
通过Json 字符串搜索
String query = "{\n" +
" \"query\": {\n" +
" \"filtered\" : {\n" +
" \"query\" : {\n" +
" \"query_string\" : {\n" +
" \"query\" : \"test\"\n" +
" }\n" +
" },\n" +
" \"filter\" : {\n" +
" \"term\" : { \"user\" : \"kimchy\" }\n" +
" }\n" +
" }\n" +
" }\n" +
"}";
Search search = new Search(query);
// multiple index or types can be added.
search.addIndex("twitter");
search.addType("tweet");
JestResult result = client.execute(search);
使用SearchSourceBuilder
SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
searchSourceBuilder.query(QueryBuilders.matchQuery("user", "kimchy"));
Search search = new Search(searchSourceBuilder.toString());
search.addIndex("twitter");
search.addType("tweet");
JestResult result = client.execute(search);
结果转换成对象
JestResult result = client.execute(search); List<Article> articles = result.getSourceAsObjectList(Article.class);
如果要阅读复杂的查询，请这里走-->
获取索引文档
Get get = new Get.Builder("1").index("twitter").type("tweet").build();
JestResult result = client.execute(get);
结果转换成对象
Get get = new Get.Builder("1").index("twitter").type("tweet").build();
JestResult result = client.execute(get);
Article article = result.getSourceAsObject(Article.class);
更新索引文档
String script = "{\n" +
" \"script\" : \"ctx._source.tags += tag\",\n" +
" \"params\" : {\n" +
" \"tag\" : \"blue\"\n" +
" }\n" +
"}";
client.execute(new Update.Builder(script).index("twitter").type("tweet").id("1").build());
删除文档
client.execute(new Delete.Builder("1").index("twitter").type("tweet").build());
批量操作
通过API批量操作 index/delete 操作，可以大大增加索引速度。
Bulk bulk = new Bulk("twitter", "tweet");
bulk.addIndex(new Index.Builder(article1).build());
bulk.addIndex(new Index.Builder(article2).build());
bulk.addDelete(new Delete.Builder("1").build());
client.execute(bulk);
集合批量操作
Bulk bulk = new Bulk("twitter", "tweet");
Article article1 = new Article("tweet1");
Article article2 = new Article("tweet1");
bulk.addIndexList(Arrays.asList(article1, article2););
client.execute(bulk);
设置参数
ElasticSearch要求参数来设置属性，如 routing, versioning 操作类型等
比如设置“refresh” 为 “true”
Index index = new Index.Builder("{\"user\":\"kimchy\"}").index("cvbank").type("candidate").id("1").build();
index.addParameter(Parameters.REFRESH, true);
client.execute(index);
同步操作
Jest http Client 支持 blocking IO asynchronously.
使用Jest 同步操作实例
client.executeAsync(action,new JestResultHandler<JestResult>() {
@Override
public void completed(JestResult result) {
... do process result ....
}
@Override
public void failed(Exception ex) {
... catch exception ...
}
});
配置在同一网段内发下其它节点设置
//enable host discovery clientConfig.getProperties().put(ClientConstants.DISCOVERY_ENABLED, true); //boolean clientConfig.getProperties().put(ClientConstants.DISCOVERY_FREQUENCY, 1l); //long clientConfig.getProperties().put(ClientConstants.DISCOVERY_FREQUENCY_TIMEUNIT, TimeUnit.MINUTES); //timeunit
source -->