工作记录(01)：使用JDK类ScriptEngine实现复杂逻辑运算的一次bug修复

模拟线上代码(当时服务器上JDK版本为1.7)

import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import javax.script.ScriptException;

public class Test03 {
	
	public static void main(String[] args) {
		// 条件表达式,要求变量a1的值等于变量a2的值、并且变量a3包含"风险"标识
        String conditionalExpression = "a1==a2&&a3.indexOf(\"风险\")!=-1";
        Boolean result = null;
        try {
        	ScriptEngineManager manager = new ScriptEngineManager();
        	ScriptEngine engine = manager.getEngineByName("js");
        	engine.eval("importPackage(java.util)");
        	
        	// 给变量赋值
			engine.put("a1", 2);
			engine.put("a2", 2);
			engine.put("a3", "炒股有风险，投资需谨慎。");
			Object result1 = engine.eval(conditionalExpression);
			if("java.lang.Boolean".equals(result1.getClass().getName())){
				result = (Boolean)result1;
	        }
		} catch (ScriptException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
        System.out.println("result = " + result);
	}
}

在JDK1.7环境下运行代码，其结果是正常的

==================================================================

现在将JDK升级到11，再运行此代码时，就报错了

javax.script.ScriptException: ReferenceError: "importPackage" is not defined in <eval> at line number 1
	at jdk.nashorn.api.scripting.NashornScriptEngine.throwAsScriptException(NashornScriptEngine.java:564)
	at jdk.nashorn.api.scripting.NashornScriptEngine.evalImpl(NashornScriptEngine.java:548)
	at jdk.nashorn.api.scripting.NashornScriptEngine.evalImpl(NashornScriptEngine.java:528)
	at jdk.nashorn.api.scripting.NashornScriptEngine.evalImpl(NashornScriptEngine.java:524)
	at jdk.nashorn.api.scripting.NashornScriptEngine.eval(NashornScriptEngine.java:194)
	at javax.script.AbstractScriptEngine.eval(AbstractScriptEngine.java:264)
	at study.alibaba.Test03.main(Test03.java:16)
Caused by: <eval>:1 ReferenceError: "importPackage" is not defined
	at jdk.nashorn.internal.runtime.ECMAErrors.error(ECMAErrors.java:56)
	at jdk.nashorn.internal.runtime.ECMAErrors.referenceError(ECMAErrors.java:318)
	at jdk.nashorn.internal.runtime.ECMAErrors.referenceError(ECMAErrors.java:290)
	at jdk.nashorn.api.scripting.NashornScriptEngine.__noSuchProperty__(NashornScriptEngine.java:274)
	at jdk.nashorn.internal.scripts.Script$engine._L35(nashorn:engine/resources/engine.js:37)
	at jdk.nashorn.internal.scripts.Script$\^eval\_.runScript(<eval>:1)
	at jdk.nashorn.internal.runtime.ScriptFunctionData.invoke(ScriptFunctionData.java:498)
	at jdk.nashorn.internal.runtime.ScriptFunction.invoke(ScriptFunction.java:206)
	at jdk.nashorn.internal.runtime.ScriptRuntime.apply(ScriptRuntime.java:378)
	at jdk.nashorn.api.scripting.NashornScriptEngine.evalImpl(NashornScriptEngine.java:546)
	... 5 more
result = null

原来ScriptEngine在后来的JDK版本中，语法进行了调整，已经不支持【importPackage(java.util)】这种写法了

我们将engine.eval("importPackage(java.util)");这行代码删除，再执行就正常了。

result = true

 

来源：oschina

链接：https://my.oschina.net/dami1203/blog/3165792