如何用樹以角度下載檔案？-有解無憂

目前我正在嘗試從樹中實作下載檔案。一棵樹有孩子和附件。用戶可以選擇多個子樹或多個附件。后端服務器應該從資料庫中收集資料并基于樹構建一個 zip 檔案。如果我正確實施它，請告訴我。

下載檔案 service.ts

import { HttpClient } from '@angular/common/http';
import { Injectable } from '@angular/core';
import { environment } from 'src/environments/environment';

@Injectable({
  providedIn: 'root'
})
export class DownloadService {
  downloadList: any[] = [];
  downloadAttachmentList: any[] = [];
  isDownloadInQueue = false;

  constructor(
    private http: HttpClient
  ) { }

  clear() {
    this.downloadList.splice(0, this.downloadList.length);
    this.downloadAttachmentList.splice(0, this.downloadAttachmentList.length);
    this.isDownloadInQueue = false;

  }

  addDownloadItemToList(node: any) {
    this.isDownloadInQueue = true;
    this.downloadList.push(node);
  }

  removeDownloadItemToList(node: any) {
    let nodeIndex = this.downloadList.indexOf(node);
    if(nodeIndex >= 0) {
      // remove it
      this.downloadList.splice(nodeIndex, 1);
      if(this.downloadList.length == 0 && this.downloadAttachmentList.length == 0)
       this.isDownloadInQueue = false;
    }
  }

  addDownloadAttachmentItemToList(node: any) {
    this.isDownloadInQueue = true;
    this.downloadAttachmentList.push(node);
  }

  removeDownloadAttachmentItemToList(node: any) {
    let nodeIndex = this.downloadAttachmentList.indexOf(node);
    if(nodeIndex >= 0) {
      // remove it
      this.downloadAttachmentList.splice(nodeIndex, 1);
      if(this.downloadAttachmentList.length == 0 && this.downloadAttachmentList.length == 0)
       this.isDownloadInQueue = false;
    }
  }

  downloadFilesAsZip(nodeName: string | undefined) {
    return this.http.post(`${environment.server}/download`, {
      children: this.downloadList,
      attachments: this.downloadAttachmentList,
      nodeName: nodeName
    }, {
      responseType: 'arraybuffer'
    });
  }
}

檔案夾 explorer.ts

  toggleDownloadSelected(selected_leaf: any, event: any) {
    if(event.target.checked)
      this.downloadService.addDownloadItemToList(selected_leaf);
    else
      this.downloadService.removeDownloadItemToList(selected_leaf);
  }

  toggleDownloadAttachmentSelected(selected_leaf: any, event: any) {
    if(event.target.checked)
      this.downloadService.addDownloadAttachmentItemToList(selected_leaf);
    else
      this.downloadService.removeDownloadAttachmentItemToList(selected_leaf);
  }

html模板.htlm

 <span>
                <input type="checkbox" class="chk-btn" (change)="toggleDownloadSelected(leaf, $event)"/>
            </span>

package com.example.treetable;

import org.apache.tomcat.util.http.fileupload.IOUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;

import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.ArrayList;
import java.util.List;
import java.util.Optional;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;

@RestController
@RequestMapping("download")
@CrossOrigin("http://localhost:4200")
public class DownloadController {
    @Autowired
    private AttachmentDataRepository attachmentDataRepository;

    @PostMapping
    @RequestMapping(produces = "application/zip")
    public void downloadResourceAsZip(
            @RequestBody FileTreeDto fileTree,
            HttpServletResponse response
    ) throws IOException {
        List<AttachmentData> dataList = attachmentDataRepository.findAll();
        ZipOutputStream zos = new ZipOutputStream(response.getOutputStream());
        createListOfZipEntry(fileTree, fileTree.getNodeName() , zos);
        zos.closeEntry();
        zos.close();
    }

    private List<ZipEntry> createListOfZipEntry(FileTreeDto  fileTreeDto, String rootPath, ZipOutputStream zos) throws IOException {
        List<ZipEntry> zipEntries = new ArrayList<>();
        String newRootPath = rootPath   "/"   fileTreeDto.getNodeName();
        // check if attachement arrays exist
        if(fileTreeDto.getAttachments() != null) {
            for(AttachmentDataDto dataDto: fileTreeDto.getAttachments()) {
                System.out.println("Getting by id "   dataDto.getAttachment_id());
                Optional<AttachmentData> optionalAttachmentData = attachmentDataRepository.findById(dataDto.getAttachment_id());
                if(optionalAttachmentData.isPresent()) {
                    AttachmentData data = optionalAttachmentData.get();
                    String path = newRootPath  "/"   dataDto.getName();
                    System.out.println("Path "   path);
                    ZipEntry zipEntry = new ZipEntry(path);
                    zipEntry.setSize(data.getFile().length);
                    zos.putNextEntry(zipEntry);
                    zos.write(data.getFile());
                    zipEntries.add(zipEntry);
                }
            }


        }
        if(fileTreeDto.getChildren() == null || fileTreeDto.getChildren().size() <= 0)
            return zipEntries;

        for (FileTreeDto ftD : fileTreeDto.getChildren()) {
            zipEntries.addAll(createListOfZipEntry(ftD, newRootPath , zos));
        }

        return zipEntries;
    }
}

import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.Data;
import lombok.NoArgsConstructor;

import java.util.List;

@Data
@Builder
@AllArgsConstructor
@NoArgsConstructor
public class FileTreeDto {
    private String nodeName;
    private List<FileTreeDto> children;
    private List<AttachmentDataDto> attachments;
}

uj5u.com熱心網友回復：

import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@Builder
@AllArgsConstructor
@NoArgsConstructor
public class AttachmentRequestDto {
    private Long id;
    private String name;
    private Long attachment_id;
}

uj5u.com熱心網友回復：

  downloadFile() {
    if(!this.downloadService.isDownloadInQueue) return;
    this.downloadService.downloadZipOrFiles(this.selected_leaf?.nodeName);    
  }

 downloadZipOrFiles(nodeName: string | undefined) {
    if(this.downloadList.length <= 0 && this.downloadAttachmentList.length > 0) {
      this.downloadAttachmentOnly(nodeName);
    }      
    else
    {
      if(this.downloadList.length > 0 || this.downloadAttachmentList.length > 0) {
        this.downloadFilesAsZip(nodeName);      
      }
    }        
  }

  downloadAttachmentOnly(nodeName: string | undefined) {
    let attachmentIds = this.downloadAttachmentList.map((attachment) => attachment.attachment_id);
    this.http.post(`${environment.server}/download/files?ids=` attachmentIds, {
      
    }).subscribe(
      (res: any) => {
        if(res && res.length > 0) {
          for(let i = 0; i < res.length; i   ) {
            var blob=new Blob([res[i].file], {type: res[i].docType});// change resultByte to bytes
            var link=document.createElement('a');
            link.href=window.URL.createObjectURL(blob);
            link.download=res[i].fileName;
            link.click();
          }

          this.clear();
        }
      }
    );
  }

  downloadFilesAsZip(nodeName: string | undefined) {
    this.http.post(`${environment.server}/download`, {
      children: this.downloadList,
      attachments: this.downloadAttachmentList,
      nodeName: nodeName
    }, {
      responseType: 'arraybuffer'
    }).subscribe(
      res => {
        const blob = new Blob([res], {
          type: 'application/zip'
        });
        var link=document.createElement('a');
        link.href=window.URL.createObjectURL(blob);
        link.download = nodeName ? nodeName : 'downloadds';
        link.click();
        // const url = window.URL.createObjectURL(blob);
        // window.open(url);
        this.clear();
      }
    );
  }

uj5u.com熱心網友回復：

  downloadFile() {
    if(!this.downloadService.isDownloadInQueue) return;
    this.downloadService.downloadFilesAsZip(this.selected_leaf?.nodeName)    
      .subscribe(
        res => {
          const blob = new Blob([res], {
            type: 'application/zip'
          });
          const url = window.URL.createObjectURL(blob);
          window.open(url);
          this.downloadService.clear();
        }
      );
  }

uj5u.com熱心網友回復：

 @PostMapping("files")
    public ResponseEntity downloadFiles(
            @RequestParam("ids") Long[] attachmentIds
    ) throws IOException {
        List<AttachmentData> dataList = this.attachmentDataRepository.getDataByAttachmentIds(attachmentIds);
        return ResponseEntity.ok(dataList);
    }


    private List<ZipEntry> createListOfZipEntry(FileTreeDto  fileTreeDto, String rootPath, ZipOutputStream zos) throws IOException {
        List<ZipEntry> zipEntries = new ArrayList<>();
        String newRootPath = "";
        if(!rootPath.equalsIgnoreCase(fileTreeDto.getNodeName())) {
            newRootPath = rootPath   "/"   fileTreeDto.getNodeName();
        }else{
            newRootPath = rootPath;
        }
        // check if attachement arrays exist
        if(fileTreeDto.getAttachments() != null) {
            for(AttachmentDataDto dataDto: fileTreeDto.getAttachments()) {
                System.out.println("Getting by id "   dataDto.getAttachment_id());
                Optional<AttachmentData> optionalAttachmentData = attachmentDataRepository.findById(dataDto.getAttachment_id());
                if(optionalAttachmentData.isPresent()) {
                    AttachmentData data = optionalAttachmentData.get();
                    String path = newRootPath  "/"   dataDto.getName();
                    System.out.println("Path "   path);
                    ZipEntry zipEntry = new ZipEntry(path);
                    zipEntry.setSize(data.getFile().length);
                    zos.putNextEntry(zipEntry);
                    zos.write(data.getFile());
                    zipEntries.add(zipEntry);
                }
            }


        }
        if(fileTreeDto.getChildren() == null || fileTreeDto.getChildren().size() <= 0)
            return zipEntries;

        for (FileTreeDto ftD : fileTreeDto.getChildren()) {
            zipEntries.addAll(createListOfZipEntry(ftD, newRootPath , zos));
        }
        return zipEntries;
    }

@Query("SELECT a FROM AttachmentData a where a.id in :attachmentIds")
    List<AttachmentData> getDataByAttachmentIds(Long[] attachmentIds);

uj5u.com熱心網友回復：

  syncTree() {
    this.is_syncing = true;
    this.route.params.subscribe(param => {
      if(param['id']) {
        this.fileService.getFundTreeByFundId(param['id'])
          .pipe(
            delay(1000)
          )
          .subscribe(
            res => {},
            err => {},
            () => {
                this.is_syncing = false;
            }
        );
      }
    });
  }

uj5u.com熱心網友回復：

.spin {
  animation-name: spin;
  animation-duration: 1000ms;
  animation-iteration-count: infinite;
  animation-timing-function: linear; 
}

@keyframes spin {
  from {
      transform:rotate(0deg);
  }
  to {
      transform:rotate(360deg);
  }
}

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