JAVA使用脚本引擎执行JS

import java.io.File;
import java.lang.reflect.Field;
import java.util.Arrays;

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

public class JavaExecScriptDemo {
  
  public static void main(String[] args) {
    System.out.println(jsObjFunc());
    System.out.println(Arrays.toString(getArray()));
    System.out.println(jsCalculate("a=1+2+3+(2*2)"));
    jsFunction();
    jsVariables();
  }

  /**
   * 运行JS对象中的函数
   * 
   * @return
   */
  public static Object jsObjFunc() {
    String script =
        "var obj={run:function(){return 'run method : return:\"abc'+this.next('test')+'\"';},next:function(str){return ' 我来至next function '+str+')'}}";
    ScriptEngineManager sem = new ScriptEngineManager();
    ScriptEngine scriptEngine = sem.getEngineByName("js");
    try {
      scriptEngine.eval(script);
      Object object = scriptEngine.get("obj");
      Invocable inv2 = (Invocable) scriptEngine;
      return (String) inv2.invokeMethod(object, "run");
    } catch (Exception e) {
      e.printStackTrace();
    }
    return null;
  }

  /**
   * 获取js对象数字类型属性
   * 
   * @return
   */
  public static Object[] getArray() {
    ScriptEngineManager sem = new ScriptEngineManager();
    String script = "var obj={array:['test',true,1,1.0,2.11111]}";

    ScriptEngine scriptEngine = sem.getEngineByName("js");
    try {
      scriptEngine.eval(script);
      Object object2 = scriptEngine.eval("obj.array");
      Class<?> clazz = object2.getClass();
      Field denseField = clazz.getDeclaredField("dense");
      denseField.setAccessible(true);
      return (Object[]) denseField.get(object2);
    } catch (Exception e) {
      e.printStackTrace();
    }
    return null;
  }

  /**
   * JS计算
   * 
   * @param script
   * @return
   */
  public static Object jsCalculate(String script) {
    ScriptEngineManager manager = new ScriptEngineManager();
    ScriptEngine engine = manager.getEngineByName("javascript");
    try {
      return (Object) engine.eval(script);
    } catch (ScriptException ex) {
      ex.printStackTrace();
    }
    return null;
  }

  /**
   * 运行JS基本函数
   */
  public static void jsFunction() {
    ScriptEngineManager sem = new ScriptEngineManager();
    ScriptEngine se = sem.getEngineByName("javascript");
    try {
      String script = "function say(name){ return 'hello,'+name; }";
      se.eval(script);
      Invocable inv2 = (Invocable) se;
      String res = (String) inv2.invokeFunction("say", "test");
      System.out.println(res);
    } catch (Exception e) {
      e.printStackTrace();
    }
  }

  /**
   * JS中变量使用
   */
  public static void jsVariables() {
    ScriptEngineManager sem = new ScriptEngineManager();
    ScriptEngine engine = sem.getEngineByName("javascript");
    File file = new File("/data/js.txt");
    engine.put("file", file);
    try {
      engine.eval("println('path:'+file.getAbsoluteFile())");
    } catch (ScriptException e) {
      e.printStackTrace();
    }

  }
}

执行Main函数返回结果如下

run method : return:"abc 我来至next function test)"

[test, true, 1.0, 1.0, 2.11111]

10.0

hello,test

path:/data/js.txt