Java表达式引擎

执行效率

在本地简单测试这几种表达式的执行时间，在频繁执行中mvel表现较好，以下数据仅供参考，未取平均值。

OGNL表达式

• 依赖

<!-- https://mvnrepository.com/artifact/ognl/ognl -->
<dependency>
    <groupId>ognl</groupId>
    <artifactId>ognl</artifactId>
    <version>3.2.21</version>
</dependency>

• 示例

import ognl.Ognl;
import ognl.OgnlException;
import org.junit.Test;

import java.util.HashMap;
import java.util.Map;

public class ExpressionTest {
	@Test
    public void ognlExpression() throws OgnlException {
        String expressionString = "name.equals('李思')";
        String expressionString2 = "age + 2";
        Map map = new HashMap();
        map.put("name", "李思");
        map.put("age", 18);

        Object expression = Ognl.parseExpression(expressionString);
        Boolean resultBoolean = (Boolean) Ognl.getValue(expression, map);
        Integer resultString = (Integer) Ognl.getValue(expressionString2, map);
        System.out.println("OGNL:" + resultBoolean);
        System.out.println("OGNL:" + resultString);
    }
}
输出：
	OGNL:true
	OGNL:20

MVEL表达式

• 依赖

<!-- https://mvnrepository.com/artifact/org.mvel/mvel -->
<dependency>
    <groupId>org.mvel</groupId>
    <artifactId>mvel</artifactId>
    <version>2.0beta1</version>
</dependency>

• 示例

import org.junit.Test;
import org.mvel.MVEL;

import java.util.HashMap;
import java.util.Map;

public class ExpressionTest {
	@Test
    public void mvelExpression(){
        String expressionString = "name.equals('李思')";
        String expressionString2 = "age + 2";
        Map map = new HashMap();
        map.put("name", "李思");
        map.put("age", 18);

        Boolean resultBoolean = MVEL.evalToBoolean(expressionString, map);
        Integer resultInteger = MVEL.eval(expressionString2, map, Integer.class);
        System.out.println("MVEL:" + resultBoolean);
        System.out.println("MVEL:" + resultInteger);
    }
}
输出：
	MVEL:true
	MVEL:20

SPEL表达式

• 依赖

<!-- https://mvnrepository.com/artifact/org.springframework/spring-expression -->
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-expression</artifactId>
    <version>5.3.16</version>
</dependency>

• 示例

import org.junit.Test;
import org.springframework.expression.EvaluationContext;
import org.springframework.expression.ExpressionParser;
import org.springframework.expression.spel.standard.SpelExpressionParser;
import org.springframework.expression.spel.support.StandardEvaluationContext;

import java.util.HashMap;
import java.util.Map;

public class ExpressionTest {
	@Test
    public void spelExpression(){
        String expressionString = "#name.equals('李思')";
        String expressionString2 = "#age + 2";
        EvaluationContext evaluationContext = new StandardEvaluationContext();
        evaluationContext.setVariable("name", "李思");
        evaluationContext.setVariable("age", 18);
        ExpressionParser expressionParser = new SpelExpressionParser();
        Boolean resultBoolean = expressionParser.parseExpression(expressionString).getValue(evaluationContext, Boolean.class);
        Integer resultInteger = expressionParser.parseExpression(expressionString2).getValue(evaluationContext, Integer.class);
        System.out.println("SPEL:" + resultBoolean);
        System.out.println("SPEL:" + resultInteger);
    }
}
输出：
    SPEL:true
	SPEL:思

Jxel表达式

• 依赖

<!-- https://mvnrepository.com/artifact/org.apache.commons/commons-jexl3 -->
<dependency>
	<groupId>org.apache.commons</groupId>
	<artifactId>commons-jexl3</artifactId>
	<version>3.1</version>
</dependency>

• 示例

import org.apache.commons.jexl3.JexlBuilder;
import org.apache.commons.jexl3.JexlContext;
import org.apache.commons.jexl3.JexlEngine;
import org.apache.commons.jexl3.MapContext;
import org.junit.Test;

import java.util.HashMap;
import java.util.Map;

public class ExpressionTest {
@Test
    public void jexlExpression(){
        String expressionString = "name.equals('李思')";
        String expressionString2 = "age + 2";
        JexlContext jc = new MapContext();
        jc.set("name", "李思");
        jc.set("age", 18);

        JexlEngine jexl = new JexlBuilder().create();
        Boolean resultBoolean = (Boolean) jexl.createExpression(expressionString).evaluate(jc);
        Integer resultInteger = (Integer) jexl.createExpression(expressionString2).evaluate(jc);

        System.out.println("Jexl:" + resultBoolean);
        System.out.println("Jexl:" + resultInteger);
    }
}
输出：
    Jexl:true
    Jexl:20

Groovy表达式

• 依赖

<!-- https://mvnrepository.com/artifact/org.codehaus.groovy/groovy -->
<dependency>
    <groupId>org.codehaus.groovy</groupId>
    <artifactId>groovy</artifactId>
    <version>2.5.6</version>
</dependency>

• 示例

import groovy.lang.Binding;
import groovy.lang.GroovyShell;
import org.junit.Test;

import java.util.HashMap;
import java.util.Map;

public class ExpressionTest {
    @Test
    public void groovyExpression(){
        String expressionString = "name.equals('李思')";
        String expressionString2 = "age + 2";
        Binding binding = new Binding();
        binding.setVariable("name", "李思");
        binding.setVariable("age", 18);

        GroovyShell shell = new GroovyShell(binding);
        Boolean resultBoolean = (Boolean) shell.evaluate(expressionString);
        Integer resultInteger = (Integer) shell.evaluate(expressionString2);

        System.out.println("Groovy:" + resultBoolean);
        System.out.println("Groovy:" + resultInteger);
    }
}
输出：
    Jexl:true
    Jexl:20