我想使用 Angular 6 代码实现文件下载:
休息 API:
private static final Logger LOG = LoggerFactory.getLogger(DownloadsController.class);
private static final String EXTERNAL_FILE_PATH = "/Users/test/Documents/blacklist_api.pdf";
@GetMapping("export")
public ResponseEntity<InputStreamResource> export() throws IOException {
ClassPathResource pdfFile = new ClassPathResource(EXTERNAL_FILE_PATH);
HttpHeaders headers = new HttpHeaders();
headers.add("Cache-Control", "no-cache, no-store, must-revalidate");
headers.add("Pragma", "no-cache");
headers.add("Expires", "0");
return ResponseEntity.ok().headers(headers).contentLength(pdfFile.contentLength())
.contentType(MediaType.parseMediaType("application/pdf"))
.body(new InputStreamResource(pdfFile.getInputStream()));
}
服务:
import {Component, OnInit} from '@angular/core';
import {DownloadService} from "../service/download.service";
import {ActivatedRoute, Router} from "@angular/router";
import {flatMap} from "rxjs/internal/operators";
import {of} from "rxjs/index";
import { map } from 'rxjs/operators';
@Component({
selector: 'app-download',
templateUrl: './download.component.html',
styleUrls: ['./download.component.scss']
})
export class DownloadComponent implements OnInit {
constructor(private downloadService: DownloadService,
private router: Router,
private route: ActivatedRoute) {
}
ngOnInit() {
}
export() {
this.downloadService.downloadPDF().subscribe(res => {
const fileURL = URL.createObjectURL(res);
window.open(fileURL, '_blank');
});
}
}
组件:
import {Component, OnInit} from '@angular/core';
import {DownloadService} from "../service/download.service";
import {ActivatedRoute, Router} from "@angular/router";
import {flatMap} from "rxjs/internal/operators";
import {of} from "rxjs/index";
import { map } from 'rxjs/operators';
@Component({
selector: 'app-download',
templateUrl: './download.component.html',
styleUrls: ['./download.component.scss']
})
export class DownloadComponent implements OnInit {
constructor(private downloadService: DownloadService,
private router: Router,
private route: ActivatedRoute) {
}
ngOnInit() {
}
export() {
this.downloadService.downloadPDF().subscribe(res => {
const fileURL = URL.createObjectURL(res);
window.open(fileURL, '_blank');
});
}
}
当我点击下载按钮时,我得到这个 Spring 错误:
15:28:02,819 ERROR [org.springframework.boot.web.servlet.support.ErrorPageFilter] (default task-1) Forwarding to error page from request [/downloads/export] due to exception [class path resource [Users/test/Documents/blacklist_api.pdf] cannot be resolved to URL because it does not exist]: java.io.FileNotFoundException: class path resource [Users/test/Documents/blacklist_api.pdf] cannot be resolved to URL because it does not exist
at deployment.test_admin.war//org.springframework.core.io.ClassPathResource.getURL(ClassPathResource.java:195)
该文件存在于目录中,但看起来它位于 war 包之外,而且我无法访问它。有什么方法可以配置 Java 来访问它并下载它吗?
最佳答案
由于您使用的是 ClasspathResource,因此您只能获取类路径“内”的文件。
如果您的文件在类路径之外,您将无法通过这种方式获取它。
private static final Logger LOG = LoggerFactory.getLogger(DownloadsController.class);
private static final String EXTERNAL_FILE_PATH = "/Users/test/Documents/blacklist_api.pdf";
@GetMapping("export")
public ResponseEntity<InputStreamResource> export() throws IOException {
File pdfFile = Paths.get(EXTERNAL_FILE_PATH).toFile();
HttpHeaders headers = new HttpHeaders();
headers.add("Cache-Control", "no-cache, no-store, must-revalidate");
headers.add("Pragma", "no-cache");
headers.add("Expires", "0");
return ResponseEntity.ok().headers(headers).contentLength(pdfFile.length())
.contentType(MediaType.parseMediaType("application/pdf"))
.body(new FileInputStream(pdfFile));
}
我改变了你获取文件的方式,一个文件而不是一个 ClassPathResource。
我临时修改了那段代码,如有错误请见谅。希望对你有帮助
关于java - 无法下载文件 : cannot be resolved to URL because it does not exist with Spring,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/53239615/