java中運算子的解析和計算

標籤：

package com.LBH; import javax.script.ScriptEngine;import javax.script.ScriptEngineManager;import javax.script.ScriptException; import com.singularsys.jep.Jep;import com.singularsys.jep.bigdecimal.BigDecComponents; public class JieXi {     public static boolean getExpressionValue(String expression) {        Jep jep = new Jep(new BigDecComponents());        jep.addStandardConstants();        Object result = null;        try {            jep.parse(expression);            result = jep.evaluate();        } catch (Exception e) {            e.printStackTrace();        }        return (Boolean) result;     }     public static Object getMathValue(String str) throws ScriptException{        ScriptEngineManager manager = new ScriptEngineManager();        ScriptEngine engine = manager.getEngineByName("js");        engine.put("a", true);        engine.put("b", false);        engine.put("c", true);        Object result = engine.eval(str);        return result;    }         public static void main(String[] args) throws Exception {         String str = "(a||b)&&c";        System.out.println(str);        Object result = getMathValue(str);        System.out.println("關係運算子計算結果，類型:" + result.getClass().getName()                + ",結果:" + result);        System.out.println("******************\n數學運算子"                + getExpressionValue("(1+3)&&(0+10)"));    }}

運算結果：

(a||b)&&c

關係運算子計算結果，類型:java.lang.Boolean,結果:true

******************

數學運算子true

 

 

參考：http://blog.sina.com.cn/s/blog_acdc06250101p5dh.html

java中運算子的解析和計算