ScriptEngineManager sem = new ScriptEngineManager();
ScriptEngine engine = sem.getEngineByName("javascript");
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.net.URL;
import java.util.List;
import javax.script.Invocable;
import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import javax.script.ScriptException;
/*
* 测试脚本执行JavaScript代码
*/
public class Demo01 {
public static void main(String[] args) throws Exception {
//获取脚本对象
ScriptEngineManager sem = new ScriptEngineManager();
ScriptEngine engine = sem.getEngineByName("javascript");
//定义变量,存储到引擎中,使得Java和JavaScript代码都可以访问
engine.put("msg", "good man!");
//用字符串保存JavaScript代码
String str = "var user = {name:'huicheng' , age:18, schools:['清华大学','北京大学']};";
str += "println(user.name);"; //注意别漏了字符串中的分号
//执行脚本
engine.eval(str);
//用JavaScript修改变量msg的值
engine.eval("msg = 'qinghua is a good school';");
//用Java打印mag的值
System.out.println(engine.get("msg"));
System.out.println("################");
//定义函数
engine.eval("function add(a, b){var sum = a+b; return sum;}");
//取得调用接口
Invocable jsInvoke = (Invocable) engine;
//执行脚本中定义的方法
Object result1 = jsInvoke.invokeFunction("add", new Object[]{13, 20});
//Object result11 = jsInvoke.invokeFunction("add", 13, 20);
System.out.println(result1);
//导入其他Java包中的类,使用其他包中的Java类
String jsCode = "importPackage(java.util); var list=Arrays.asList([\"清华\",\"北大\"]);";
engine.eval(jsCode);
List<String> list2 = (List<String>)engine.get("list");
for(String temp : list2){
System.out.println(temp);
}
//执行一个js文件(将a.js放到项目的src下即可)
URL url = Demo01.class.getClassLoader().getResource("a.js"); //读取项目中的源文件
FileReader fr = new FileReader(url.getPath());
engine.eval(fr);
fr.close(); //仅是测试就不用try catch
}
}
a.js文件的代码:
function test(){
var a = 3;
var b = 4;
println("invoke js file:"+(a+b));
}
test();
执行结果:
huicheng
qinghua is a good school
################
33.0
清华
北大
invoke js file:7
本文地址:https://blog.csdn.net/HC199854/article/details/107237610
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