uni-app本地离线打包后，如何调用自定义JAVA类中方法？

分类：uni-app

请问uni-app本地离线打包后，如何调用自定义JAVA类中方法？

一、在H5+ 中是可以调用成功的，代码如下：
1、网页中：

function plusReady(){  
    var NjsHello = plus.android.importClass("com.example.H5PlusPlugin.HelloWorld");  
    alert(NjsHello.BIRTHDAY);  
    var hello = new NjsHello();  
    hello.setUsername('hello h5+!');  
    var wv = plus.android.currentWebview();  
    hello.print(0,0,0,0,wv);  
    var sname = hello.getUsername();  
    console.log( "NjsHello Final's value: "+sname );  
}

2、JAVA代码：

public class HelloWorld {  
    printer mPrinter = new printer();  

    public static final String BIRTHDAY="2007-03-16";  
    public String username ="2007-03-16";  

    public String getUsername() {  

        try {  

            int result = mPrinter.Open();  
            if (result ==0){  
                mPrinter.PrintLineInit(50);  
                mPrinter.PrintLineStringByType("HelloWorld",40,printer.PrintType.Centering,false);  
                mPrinter.PrintLineEnd();  
                mPrinter.Close();  
            }  
        }  
        catch (Exception e){  
            e.printStackTrace();  
        }  

        return username;  
    }  

    public  void setUsername(String s){  
        username = s;  
        System.out.println("call:"+username);  
    }  

    public  void print(int x, int y, int width, int height, WebView wv){  
        username = wv.getUrl();  
    }  

    public static void main( String args[] ) {  
        HelloWorld helloWorld = new HelloWorld();  
        helloWorld.setUsername("hello");  
        System.out.println(helloWorld.getUsername());  
    }  

}

二、上面代码在uni-app中却不能正常执行，

<template>  
    <view class="content">  
        <text class="title">{{title}}</text>  
        <button class="button" v-on:click="print()">print</button>  
        <button class="button" v-on:click="showMessage('fuck')">message</button>  
    </view>  
</template>  

<script>  
    export default {  
        data: {  
            title: 'Hello wf'  
        },  
        methods:{  
            print(){  
                console.log("print!")  
                var pages = getCurrentPages();  
                var page = pages[pages.length - 1];  

            // #ifdef APP-PLUS    
                        var currentWebview = page.$getAppWebview();       
            // 弹出系统提示对话框              
            plus.nativeUI.alert( "Plus is ready!", function(){  
                /*  这段正常  
                var intent = plus.android.newObject("android.content.Intent");  
                //currentWebview.loadURL("http://www.baidu.com");  
                console.log(currentWebview.getURL());  
                */  

                   //打印测试，下面三行执行没效果  
                   var hello = plus.android.newObject("com.example.H5PlusPlugin.HelloWorld");  
                   var sname = hello.getUsername();              
                   console.log( "NjsHello Final's value: "+sname );  

            }, "nativeUI", "OK" );  

            // #endif

三、问题：uni-app本地离线打包后，如何调用自定义JAVA类中方法？主要需求是ANDROID原生集成物联网终端手持机提供本机小票打印等硬件功能，并本地打包uni-app，在uni-app中以JS方式调用打印小票接口（android 原生JAVA代码）。