如何将文件从 Java 控制器下载到 javascript

Question

在 html 文件中，我有一个包含员工联系人的表格。 该表有不同的过滤器，还有一个下载文件按钮。

当按钮被按下时，函数被调用

function ParseDocument() {

    var table = document.getElementById('allContact');
    var contactDTOList = new Array();
    var i =0;

    for (var r = 2, n = table.rows.length; r < n; r++) {

        if (table.rows[r].style.display !== 'none') {
            var s = table.rows[r].cells[0].innerHTML;
            var bits = s.split(/\D/);
            var date = new Date(bits[0], --bits[1], bits[2], bits[3], bits[4], bits[5]);

            var contactDTO = {
                dateOfBirth:date.getTime(),
                firstName:table.rows[r].cells[1].innerHTML,
                lastName:table.rows[r].cells[2].innerHTML,
                email:table.rows[r].cells[3].innerHTML
        };
            contactDTOList.push(contactDTO);
            i++;
        }
    }

    $.ajax({
        type: 'POST',
        url: "/rest/bot5",
        data: JSON.stringify(contactDTOList),
        contentType: "application/json;charset=UTF-8",
        async: true,
        success: function () {
        }
    });
}

接下来，所有通过过滤器的联系人都落入控制器java中

import org.springframework.http.MediaType;
import org.springframework.web.bind.annotation.*;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.CellStyle;
import org.apache.poi.ss.usermodel.Font;
import org.apache.poi.ss.usermodel.IndexedColors;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

@RestController
@RequestMapping(value = "/test")
public class BotRestController {

    @PostMapping(value = "/bot5", produces = MediaType.APPLICATION_JSON_UTF8_VALUE)
    public FileOutputStream postOrderingTask(@RequestBody List<Contact> contactList) throws IOException {

        String[] columns = {"First Name", "Last Name", "Email", "Date Of Birth"};
        List<Contact> contacts = new ArrayList<Contact>();

        contacts.add(new Contact("Sylvain", "Saurel", "sylvain.saurel@gmail.com", "2018-09-25 16:28:47"));
        contacts.add(new Contact("Albert", "Dupond", "sylvain.saurel@gmail.com", "2018-09-25 17:28:47"));
        contacts.add(new Contact("Pierre", "Dupont", "sylvain.saurel@gmail.com", "2018-09-25 18:28:47"));
        contacts.add(new Contact("Mariano", "Diaz", "sylvain.saurel@gmail.com", "2018-09-25 19:28:47"));

        Workbook workbook = new XSSFWorkbook();
        Sheet sheet = workbook.createSheet("Contacts");

        Font headerFont = workbook.createFont();
        headerFont.setBold(true);
        headerFont.setFontHeightInPoints((short) 14);
        headerFont.setColor(IndexedColors.RED.getIndex());

        CellStyle headerCellStyle = workbook.createCellStyle();
        headerCellStyle.setFont(headerFont);

        // Create a Row
        Row headerRow = sheet.createRow(0);

        for (int i = 0; i < columns.length; i++) {
            Cell cell = headerRow.createCell(i);
            cell.setCellValue(columns[i]);
            cell.setCellStyle(headerCellStyle);
        }

        // Create Other rows and cells with contacts data
        int rowNum = 1;
        for (Contact contact : contacts) {
            Row row = sheet.createRow(rowNum++);
            row.createCell(0).setCellValue(contact.firstName);
            row.createCell(1).setCellValue(contact.lastName);
            row.createCell(2).setCellValue(contact.email);
            row.createCell(3).setCellValue(contact.dateOfBirth);
        }

        // Resize all columns to fit the content size
        for (int i = 0; i < columns.length; i++) {
            sheet.autoSizeColumn(i);
        }

        // Write the output to a file
        FileOutputStream fileOut = new FileOutputStream("contacts.xlsx");
        workbook.write(fileOut);
        fileOut.close();
        return fileOut;
    }
}

单击html中的按钮时如何下载包含联系人的文件？

Answer 1

您已将所有详细信息保存在 contacts.xlsx 中。现在作为响应从部署目录发送文件路径。 说路径 = /projectname/contacts.xlsx 在成功函数中使用 window.open(ip:port://path);

在 ajax 调用中 成功：函数（）应该是成功：函数（数据）在数据变量你会得到服务器的响应

Answer 2

返回内容类型为"application/octet-stream"的文件会提示浏览器下载文件。

Path path = Paths.get(file.getAbsolutePath());
        ByteArrayResource resource = new ByteArrayResource(Files.readAllBytes(path));

        return ResponseEntity.ok()
                .headers(headers)
                .contentLength(file.length())
                .contentType(MediaType.parseMediaType("application/octet-stream"))
                .body(resource);