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自定义elasticsearch插件实现
1 插件项目结构
这是一个传统的maven项目结构，主要是多了一些插件需要的的目录和文件
plugin.xml和plugin-descriptor.properties这两个是插件的主要配置和描述
pom.xml里面也有一些插件的配置pom.xml文件
<?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>
<name>analysis-gridsum</name>
<groupId>org.elasticsearch</groupId>
<artifactId>gridsum-plugin</artifactId>
<version>0.0.1</version>
<description>gridsum elasticsearch plugin 国双elasticsearch自定义分词插件</description>
<properties>
<elasticsearch.version>6.4.1</elasticsearch.version>
<lucene.version>7.5.0</lucene.version>
<maven.compiler.target>1.8</maven.compiler.target>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
<dependencies>
<dependency>
<groupId>org.elasticsearch</groupId>
<artifactId>elasticsearch</artifactId>
<version>${elasticsearch.version}</version>
<scope>provided</scope>
</dependency>
<!-- Testing -->
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-api</artifactId>
<version>2.7</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-core</artifactId>
<version>2.7</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.elasticsearch.test</groupId>
<artifactId>framework</artifactId>
<version>${elasticsearch.version}</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.apache.lucene</groupId>
<artifactId>lucene-test-framework</artifactId>
<version>${lucene.version}</version>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<resources>
<resource>
<directory>src/main/resources</directory>
<filtering>false</filtering>
<excludes>
<exclude>*.properties</exclude>
</excludes>
</resource>
</resources>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-assembly-plugin</artifactId>
<version>2.6</version>
<configuration>
<appendAssemblyId>false</appendAssemblyId>
<outputDirectory>${project.build.directory}/releases/</outputDirectory>
<descriptors>
<descriptor>${basedir}/src/main/assemblies/plugin.xml</descriptor>
</descriptors>
</configuration>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>single</goal>
</goals>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.5.1</version>
<configuration>
<source>${maven.compiler.target}</source>
<target>${maven.compiler.target}</target>
</configuration>
</plugin>
</plugins>
</build>
</project>
plugin.xml文件
<?xml version="1.0"?>
<assembly>
<id>analysis-gridsum</id>
<formats>
<format>zip</format>
</formats>
<includeBaseDirectory>false</includeBaseDirectory>
<fileSets>
<fileSet>
<directory>${project.basedir}/config</directory>
<outputDirectory>config</outputDirectory>
</fileSet>
</fileSets>
<files>
<file>
<source>${project.basedir}/src/main/resources/plugin-descriptor.properties</source>
<outputDirectory/>
<filtered>true</filtered>
</file>
</files>
<dependencySets>
<dependencySet>
<outputDirectory/>
<useProjectArtifact>true</useProjectArtifact>
<useTransitiveFiltering>true</useTransitiveFiltering>
<excludes>
<exclude>org.elasticsearch:elasticsearch</exclude>
</excludes>
</dependencySet>
</dependencySets>
</assembly>
plugin-descriptor.properties文件
description=${project.description}
version=${project.version}
name=${project.name}
classname=org.elasticsearch.gridsum.plugin.GridsumPlugin
java.version=${maven.compiler.target}
elasticsearch.version=${elasticsearch.version}
把项目结构和这几个文件添加好之后就可以编写插件了。
2 插件主要实现类和方法
2.1 开发插件只需要继承Plugin实现AnalysisPlugin就可以了
GridsumTokenizer是分词器，继承Tokenizer，通过重写incrementToken方法来实现自己的分词程序
GridsumAnalyzer是分析器，继承Analyzer，里面需要塞一个分词器
GridsumAnalyzerProvider是分析器提供程序，继承AbstractIndexAnalyzerProvider，通过重写get方法返回自定义分析器
GridsumTokenizerFactory是分词器工厂，继承AbstractTokenizerFactory，通过重写create方法返回自定义的分词器
GridsumPlugin自定义插件的主要实现，继承Plugin实现AnalysisPlugin，通过重写getTokenizers将分词器工厂放入map，通过重写getAnalyzers将分析器放入map（这里的key后面会用到）
结构图如下
先来看一下自定义Tokenzier，最主要的是incrementToken方法
再看一下自定义Tokenizer工厂，主要的方法是create方法返回自定义Tokenizer
看一下自定义Analyzer
在createComponents方法中返回TokenStreamComponents，里面塞了一个我们的自定义Tokenizer
再看一下Analyzer工厂
主要返回一个自定义Analyzer
最终我们看一下自定义Plugin
到这里整个插件的结构就完成了。
2.2 实现自己的分词程序
整个自定义分词的最关键方法就是自定义分词器GridsumTokenizer的incrementToken方法，通过重写该方法来实现自定义分词功能
在网上找的一个空格分词的实现
package org.elasticsearch.gridsum.plugin.extend;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.apache.lucene.analysis.Tokenizer;
import org.apache.lucene.analysis.tokenattributes.CharTermAttribute;
import org.apache.lucene.analysis.tokenattributes.OffsetAttribute;
import java.io.IOException;
public class GridsumTokenizer extends Tokenizer {
private final static Logger LOGGER = LogManager.getLogger(GridsumTokenizer.class);
private final static String PUNCTION = " -()/";
private final StringBuilder buffer = new StringBuilder();
private int suffixOffset;
private int tokenStart = 0, tokenEnd = 0;
private final CharTermAttribute termAtt = addAttribute(CharTermAttribute.class);
private final OffsetAttribute offsetAtt = addAttribute(OffsetAttribute.class);
@Override
public final boolean incrementToken() throws IOException {
clearAttributes();
buffer.setLength(0);
int ci;
char ch;
tokenStart = tokenEnd;
ci = input.read();
if(ci>64&&ci<91){
ci=ci+32;
}
ch = (char) ci;
while (true) {
if (ci == -1){
if (buffer.length() == 0)
return false;
else {
termAtt.setEmpty().append(buffer);
offsetAtt.setOffset(correctOffset(tokenStart),
correctOffset(tokenEnd));
return true;
}
}
else if (PUNCTION.indexOf(ch) != -1) {
//buffer.append(ch);
tokenEnd++;
if(buffer.length()>0){
termAtt.setEmpty().append(buffer);
offsetAtt.setOffset(correctOffset(tokenStart),
correctOffset(tokenEnd));
return true;
}else
{
ci = input.read();
if(ci>64&&ci<91){
ci=ci+32;
}
ch = (char) ci;
}
} else {
buffer.append(ch);
tokenEnd++;
ci = input.read();
if(ci>64&&ci<91){
ci=ci+32;
}
ch = (char) ci;
}
}
}
@Override
public final void end() {
final int finalOffset = correctOffset(suffixOffset);
this.offsetAtt.setOffset(finalOffset, finalOffset);
}
@Override
public void reset() throws IOException {
super.reset();
tokenStart = tokenEnd = 0;
}
}
3 验证与安装
本地测试方法如下
package org.elasticsearch.gridsum.plugin;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.tokenattributes.CharTermAttribute;
import org.elasticsearch.gridsum.plugin.extend.GridsumAnalyzer;
import org.junit.Test;
public class GridsumAnalyzerTest {
@Test
public void testAnalyzer() throws Exception {
GridsumAnalyzer analyzer = new GridsumAnalyzer();
TokenStream ts = analyzer.tokenStream("text", "我爱北京 天安门");
CharTermAttribute term = ts.addAttribute(CharTermAttribute.class);
ts.reset();
while (ts.incrementToken()) {
System.out.println(term.toString());
}
ts.end();
ts.close();
}
}
输出结果
我爱北京
天安门
程序写完后打包
mvn clean package
打包后会生成一个本地的zip包，用来在elasticsearch进行安装
安装命令（windows）
elasticsearch bin目录> elasticsearch-plugin.bat install file:D:/elastic-gridsum-plugin/target/releases/gridsum-plugin-0.0.1.zip
如果提示已经存在了，请先卸载，不过前提是不要和系统的其他插件名称一致，名称是通过plugin.xml里面的<assembly><id>来定义的
卸载方法
elasticsearch bin目录> elasticsearch-plugin.bat remove analysis-gridsum
安装成功后启动elasticsearch
elasticsearch bin目录> elasticsearch.bat
启动之后我们可以在postman验证一下
注意这里analyzer的key就是第二步重写getAnalyzers时map里面的key
完整项目下载地址
https://download.csdn.net/download/frankcheng5143/10691531