原文 http://www.cnblogs.com/luanfei/p/4029442.html
转自: http://www.chepoo.com/elasticsearch-similarity-custom-plug-in-development.html
在搜索开发中，我们要修改打分机制，就需要自定义similarity。现在来简单说一下elasticsearch下的自定义similarity 插件开发。
网上的 https://github.com/tlrx/elasticsearch-custom-similarity-provider 仅仅支持0.20.0.Beta1-SNAPSHOT版本，现在我们用的版本是elasticsearch 0.90版本以上。那个例子现在不能用，我修改了一下。
1.继承DefaultSimilarity，实现自己的搜索打分机制。
package org.elasticsearch.index.similarity;
import org.apache.lucene.search.similarities.DefaultSimilarity;
/**
* Custom similarity class
*
* @author xq
*
*/
public class CustomSimilarity extends DefaultSimilarity {
@Override
public float idf(long docFreq, long numDocs) {
return 1.0f;
}
}
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2.继续AbstractSimilarityProvider，把自定义的打分机制类加载到elasticsearch中。
package org.elasticsearch.index.similarity;
import org.elasticsearch.common.inject.Inject;
import org.elasticsearch.common.inject.assistedinject.Assisted;
import org.elasticsearch.common.settings.Settings;
/**
* Simple {@link SimilarityProvider} for a {@link CustomSimilarity}
*
* @author xq
*
*/
public class CustomSimilarityProvider extends AbstractSimilarityProvider {
private CustomSimilarity similarity;
@Inject
public CustomSimilarityProvider(@Assisted String name, @Assisted Settings settings) {
super(name);
this.similarity = new CustomSimilarity();
}
public CustomSimilarity get() {
return similarity;
}
}
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3.继承AbstractPlugin作为elasticsearch插件使用
public class CustomerSimilarityPlugin extends AbstractPlugin {
@Override public String name() {
return "customer-similarity";
}
@Override public String description() {
return "customer similarity";
}
@Override public void processModule(Module module) {
if (module instanceof SimilarityModule) {
SimilarityModule similarityModule = (SimilarityModule) module;
similarityModule.addSimilarity("customer-similarity", CustomSimilarityProvider.class);
}
}
}
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4.使用
curl -XPOST ‘http://host:port/tweeter/‘ -d ‘
{
"settings": {
"similarity": {
"index": {
"type": "org.elasticsearch.index.similarity.CustomSimilarityProvider"
},
"search": {
"type": "org.elasticsearch.index.similarity.CustomSimilarityProvider"
}
}
}
}‘
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在创建mapping的使用自定义的打分规则：
{
"news" : {
"properties" : {
"title" : { "type" : "string", "similarity" : "my_similarity" }
}
}
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在elasticsearch.yml中配置自定义的打分规则类为默认规则。 index.similarity.default.type: my_similarity
时间： 2024-10-08 02:15:06