[英]Angular 2 : How to dynamcially lazy load node_modules from library package based on requested URL
[英]How to load node-java library in an angular 2 tapp?
我正在使用https://github.com/angular/quickstart
npm install
npm install java --save
node node_modules/java/postInstall.js
npm install @types/java --save-dev
的package.json
"dependencies": {
...
"java": "^0.8.0",
...
},
"devDependencies": {
...
"@types/java": "^0.7.31",
...
},
這就是我在systemjs.config.js中添加庫的方式
map: {
...
'java': 'npm:java/lib/nodeJavaBridge.js'
},
當我運行npm start時,輸出為
終奌站:
304 GET /java/lib/nodeJavaBridge.js
304 GET /java/build/jvm_dll_path.json
404 GET /lodash
404 GET /async
404 GET /path
404 GET /fs
Chrome開發者工具控制台:
http://localhost:3000/lodash Failed to load resource: the server responded with a status of 404 (Not Found)
ZoneAwareError__zone_symbol__error: Error: (SystemJS) XHR error (404 Not Found) loading http://localhost:3000/lodash
Error: XHR error (404 Not Found) loading http://localhost:3000/lodash
...
Error loading http://localhost:3000/lodash as "lodash" from http://localhost:3000/node_modules/java/lib/nodeJavaBridge.js
...
http://localhost:3000/async Failed to load resource: the server responded with a status of 404 (Not Found)
http://localhost:3000/path Failed to load resource: the server responded with a status of 404 (Not Found)
http://localhost:3000/fs Failed to load resource: the server responded with a status of 404 (Not Found)
測試我可以加載node-java並運行java代碼的代碼是這樣的:
import { Component, OnInit} from '@angular/core';
import * as java from 'java';
@Component({
selector: 'my-app',
template: `<h1>Hello {{name}}</h1>`,
})
export class AppComponent implements OnInit {
name = 'Angular';
ngOnInit() {
var sys = java.import('java.lang.System');
sys.out.printlnSync('Hello from java :)'); // outputs to terminal
var list1 = java.newInstanceSync("java.util.ArrayList");
console.log(list1.sizeSync()); // 0
list1.addSync('item1');
console.log(list1.sizeSync()); // 1
}
}
但是由於缺少庫,因此永遠不會調用該代碼。
node_modules / java / lib / nodeJavaBridge.js包含以下幾行:
var _ = require('lodash');
var async = require('async');
var path = require('path');
var fs = require('fs');
我如何正確在angular 2 quickstart應用程序中加載node-java庫?
SystemJS不知道如何加載那些節點java依賴項,您需要告訴它在systemjs.config.js
文件中在哪里可以找到它們,例如:
map: {
...
'java': 'npm:java/lib/nodeJavaBridge.js',
'lodash': 'npm:lodash/lodash.js',
'async': 'npm:...',
'path': 'npm:...',
'fs': 'npm:...',
},
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