[英]Can a Ruby script in JRuby use my Java classes if I haven't shared them with it?
[英]Is it possible to create Java classes from JRuby and use them in Java?
我正在嘗試從JRuby擴展Lucene的Analyzer
並從java中使用它。 一個簡單的分析器看起來像:
class MyAnalyzer < Java::OrgApacheLuceneAnalysis::Analyzer
def TokenStream (file_name, reader)
result = StandardTokenizer.new(Version::LUCENE_CURRENT, reader)
result = LowerCaseFilter.new(result)
result = LengthFilter.new(result, 3, 50)
result = StopFilter.new(result, StandardAnalyzer.STOP_WORDS_SET)
result = PorterStemFilter.new(result)
result
end
end
然后我編譯它: jrubyc -c /home/camilo/trunk/utils/target/dependency/lucene-core-3.0.2.jar --javac MyAnalyzer.rb
並將其打包為jar。
現在,當嘗試在java中使用MyAnalyzer
, MyAnalyzer
是org.jruby.RubyObject
的后代,而不是org.apache.lucene.analysis.Analyzer
的后代。
有沒有辦法讓Java將MyAnalyzer
視為Analyzer
而不是RubyObject
? 或者這是否超出了JRuby現在可以做的范圍?
JRuby版本: jruby 1.6.0 (ruby 1.8.7 patchlevel 330)
根據我的理解,我猜你正在嘗試創建一個擴展Java類(使用腳本引擎)的JRuby類,並將該類交還給Java。
您的Ruby類可能如下所示:
require 'java'
require 'lucene-core.jar'
java_import 'org.apache.lucene.analysis.Analyzer'
java_import 'org.apache.lucene.analysis.standard.StandardTokenizer'
java_import 'org.apache.lucene.util.Version'
java_import 'org.apache.lucene.analysis.TokenStream'
java_import 'java.io.Reader'
class MyAnalyzer < Analyzer
def tokenStream(file_name, reader)
result = StandardTokenizer.new(Version::LUCENE_CURRENT, reader)
# ...
end
end
然后,您可以在Java中使用此類,如下所示:
import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import javax.script.ScriptException;
import java.io.FileReader;
import java.io.FileNotFoundException;
import java.io.Reader;
import org.apache.lucene.analysis.Analyzer;
public class RunMyAnalyzer {
public static void main(String[] args) throws ScriptException, FileNotFoundException {
String filename = "my-analyzer.rb";
ScriptEngineManager manager = new ScriptEngineManager();
ScriptEngine engine = manager.getEngineByName("jruby");
Reader reader = new FileReader(filename);
engine.eval(reader);
// Instantiate the JRuby class, and cast the result of eval.
Analyzer analyzer = (Analyzer) engine.eval("MyAnalyzer.new");
// You can then use this analyzer like a Lucene Analyzer
}
}
然后編譯並運行:
$ javac -cp .:lucene-core.jar:$JRUBY_HOME/lib/jruby.jar RunMyAnalyzer.java
$ java -cp .:lucene-core.jar:$JRUBY_HOME/lib/jruby.jar RunMyAnalyzer
這里的關鍵是,JRuby的生產,然后可以鑄造成一個代理類Analyzer
,在Java超類。
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