6.游戏特别离不开脚本（3）-JS脚本操作java（2）（直接解析JS公式，并非完整JS文件或者函数）

在游戏中可以考虑数据由javabean保存，逻辑方法由JS提供。

public class Bean4JS {

    
    private int id;
    private String name;
    private int age;
    
    public Bean4JS(int id, String name, int age) {
        super();
        this.id = id;
        this.name = name;
        this.age = age;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }
    
    public boolean isAdult() {
        if (this.age >= 18) {
            return true;
        }
        return false;
    }
    
}

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


public class JsUseBean {

    public static void main(String[] args) {
        Bean4JS bean = new Bean4JS(0, "adware", 19);

        ScriptEngineManager eManager = new ScriptEngineManager();
        ScriptEngine engine = eManager.getEngineByName("JavaScript");

        engine.put("bean", bean);
        try {
            //这种方式调用js属于直接解析js公式
            System.out.println("he is adult?" + engine.eval(getIsAdultScript1()));
            System.out.println("he is adult?" + engine.eval(getIsAdultScript2()));
            
            //改变bean的某一个属性
            engine.eval(getSetSmallerAgeScript());
            System.out.println(bean.getAge());
            System.out.println("he is adult?" + engine.eval(getIsAdultScript1()));

        } catch (ScriptException e) {
            e.printStackTrace();
        }
    }
    
    private static String getIsAdultScript1() {
        return "var age = bean.getAge();" +
                "if(age >= 18){flag = true} else {flag = false}";
    }
    private static String getIsAdultScript2() {
        //return "var flag = bean.isAdult();"; //这样是没有返回结果的
        return "flag = bean.isAdult();";
    }
    
    private static String getSetSmallerAgeScript() {
        return "bean.setAge(17)";
    }
    
    
}

运行结果：

he is adult?true
he is adult?true
17
he is adult?false

理想要的效果又进一步了