几款不错的java表达式引擎

import org.apache.commons.jexl.Expression;

import org.apache.commons.jexl.ExpressionFactory;

import org.apache.commons.jexl.JexlContext;

import org.apache.commons.jexl.JexlHelper;

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Opera opera = new Opera( );

opera.setName("The Magic Flute");

opera.setComposer("Mozart");

opera.setYear(1791);

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String expr = 

    "${opera.name} was composed by ${opera.composer} in " +

    "${opera.year}.";

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Expression e = ExpressionFactory.createExpression( expr );

               JexlContext jc = JexlHelper.createContext( );

               jc.getVars( ).put("opera", opera);

               String message = (String) e.evaluate(jc);

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System.out.println( message );

public class Data {

    private String name; // getter and setter omitted

}

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Data data = new Data();

data.setName("John Doe");

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ExpressionParser p = new SpelExpressionParser();

Expression e = p.parseExpression("name == ‘John Doe‘");

Boolean r = (Boolean) e.getValue(data); // will return true

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e = p.parseExpression("Hello " + name + ", how are you ?");

String text = e.getValue(data, String.class); //