HTTPClient POST尝试解析非JSON响应

Question

我正在尝试在Angular中发出请求，我知道HTTP响应不是JSON而是文本。但是，Angular似乎期待JSON响应，因为错误如下：

SyntaxError：XMLHttpRequest.c中JSON.parse（）位置0的JSON中的意外标记<

以及

解析http://localhost:9时的Http失败...

这是post方法：

return this.http.post(this.loginUrl, this.createLoginFormData(username, password), this.httpOptions)
  .pipe(
    tap( // Log the result or error
      data => console.log(data);
      error => console.log(error)
    )
  );

和标题。

private httpOptions = {

  headers: new HttpHeaders({
    'Accept': 'text/html, application/xhtml+xml, */*',
    'Content-Type': 'application/x-www-form-urlencoded',
    responseType: 'text'
  },

) };

我认为responseType: 'text'足以让Angular期待非JSON响应。

Answer 1

你把responseType: 'text'放在你的httpOptions的错误部分 - 它应该坐在headers之外，就像这样：

private httpOptions = {
  headers: new HttpHeaders({
    'Accept': 'text/html, application/xhtml+xml, */*',
    'Content-Type': 'application/x-www-form-urlencoded'
  }),
  responseType: 'text'
};

使用之前的内容，responseType的请求标头被发送到服务器，而不是简单地向Angular发送指令以将响应实际视为文本。

Answer 2

这段代码终于让我xhr下载了一个pdf文件（Angular 6 / Laravel 5.6）。下载PDF文件与文本文件的专长是'responseType': 'blob' as 'json'

showPdf(filename: String){
  this.restService.downloadFile(
     'protected/getpdf',
     {'filename': filename}
  )
}

//method from restService
public downloadFile(endpoint:String, postData:Object){

  var restService = this

  var HTTPOptions = {
     headers: new HttpHeaders({
        'Accept':'application/pdf'
     }),
     'responseType': 'blob' as 'json'
  }

  this.http.post(this.baseurl+endpoint,postData,HTTPOptions )
  .subscribe(
     res => {
        console.log(res) //do something with the blob
     },
     error => {
        console.error('download error:', error)
     }, 
     () => {
        console.log('Completed file download.')
     }
  )
}

我通过Kirk Larkins找到了解决方案（非常感谢！）和一个长角度的github问题线程https://github.com/angular/angular/issues/18586#issuecomment-323216764

Answer 3

下面给出的是从组件调用，下载blob，兼容IE和chrome：

    this.subscribe(this.reportService.downloadReport(this.reportRequest, this.password), response => {
        let blob = new Blob([response], { type: 'application/zip' });
        let fileUrl = window.URL.createObjectURL(blob);
        if (window.navigator.msSaveOrOpenBlob) {
            window.navigator.msSaveOrOpenBlob(blob, fileUrl.split(':')[1] + '.zip');
        } else {
            this.reportDownloadName = fileUrl;
            window.open(fileUrl);
        }
        this.spinner = false;
        this.changeDetectorRef.markForCheck();
    },
    error => {
        this.spinner = false;
    });

下面给出的是服务方法，它将响应类型指定为'blob'

downloadReport(reportRequest: ReportRequest, password: string): Observable<any> {
    let servicePath = `${basePath}/request/password/${password}`;
    this.httpOptions.responseType = 'blob';
    return this.endpointService.post(endpoint, servicePath, reportRequest, this.httpOptions);
}

以下是使httpClient调用的代码：

    //Make the service call:
    let obs = this.httpClient.request(method, url, options);
    //Return the observable:
    return obs;