我的nativescript应用程序没有连接到我的json服务器数据库

Question

    import { Component, OnInit, Inject } from '@angular/core';
import { Cabin } from '../shared/cabin';
import { CabinService } from '../services/cabin.service';

@Component({
  selector: 'app-cabins',
  moduleId: module.id,
  templateUrl: './cabins.component.html'
})

export class CabinsComponent  implements OnInit {
  cabins: Cabin[];

  errMess: string;

  constructor(private cabinService: CabinService,
    @Inject('BaseURL') private BaseURL) {
  }

  ngOnInit() {
    this.cabinService.getCabins()
      .subscribe(cabins => this.cabins = cabins,
        errmess => this.errMess = <any>errmess);
  }

}

我所有的橱柜。Service.ts

import { Injectable } from '@angular/core';
import { Cabin } from '../shared/cabin';
import { Observable } from 'rxjs';
import { Http, Response } from '@angular/http';
import { HttpClient, HttpHeaders } from "@angular/common/http";
import { baseURL } from '../shared/baseurl';
import { ProcessHTTPMsgService } from './process-httpmsg.service';
import { map } from "rxjs/operators";
import { catchError } from "rxjs/operators";

@Injectable()
export class CabinService {

  cabins: any[];

  constructor(private http: HttpClient,
              private processHTTPMsgService: ProcessHTTPMsgService) { }

  getCabins(): Observable<Cabin[]> {
    return this.http.get(baseURL + 'cabins')
                    .pipe(map(res => { return this.processHTTPMsgService.extractData(res); }),
                    catchError(error => { return this.processHTTPMsgService.handleError(error); }));
  }

  getCabin(id: number): Observable<Cabin> {
    return  this.http.get(baseURL + 'cabins/'+ id)
                    .pipe(map(res => { return this.processHTTPMsgService.extractData(res); }),
                    catchError(error => { return this.processHTTPMsgService.handleError(error); }));
  }

  getFeaturedCabin(): Observable<Cabin> {
    return this.http.get(baseURL + 'cabins?featured=true')
                    .pipe(map(res => { return this.processHTTPMsgService.extractData(res)[0]; }),
                    catchError(error => { return this.processHTTPMsgService.handleError(error); }));
  }

}

我的app.module.ts

    imports: [
        NativeScriptHttpClientModule,
        NativeScriptModule,
        AppRoutingModule
    ],
providers: [
    {provide: 'BaseURL', useValue: baseURL},
    CabinService,
    ProcessHTTPMsgService
]

我在控制台收到这条消息

×执行命令'javac'时出错。确保您已经安装了Java Development Kit(JDK)并设置了JAVA_HOME环境变量。您将无法为Android构建您的项目。为了能够为Android构建，请验证您是否安装了Java Development Kit(JDK)，并按照http://docs.nativescript.org/setup/ns-cli-setup/ns-setup-win.html#system-requirements中描述的系统需求配置了它

×警告：Java Development Kit(JDK)未安装或配置不正确。您将无法使用Android SDK，并且可能无法执行一些与Android相关的操作。为了确保您可以为Android开发和测试应用程序，请验证您是否安装了JDK，如http://docs.oracle.com/javase/8/docs/technotes/guides/install/install_overview.html（对于JDK 8）中所述。

Answer 1

您应该使用HttpClient而不是“HTTP”。类似于这样：

AppModule：

@NgModule({
...
imports: [
NativeScriptHttpModule
]
})
export class AppModule {}

然后，在你的服务中：