String scmIdc = "https://xx/invoicePDFDownload";
    String basePath = "C:\\Users\\xx\\src\\main\\resources\\";

    @Test
    public void downloadByInvoiceNo() throws IOException {
        List<String> invoiceList = MyUtils.readTxtFileAsList(basePath + "Invoices.txt");
        for (String invoiceNo : invoiceList) {
            InputStream inputStream = given().param("invoiceNumber", invoiceNo).get(scmIdc).asInputStream();
            MyUtils.transferInputStreamToFile(inputStream, new File(basePath + "invoice\\" + "invoice-" + invoiceNo + ".pdf"));
        }
    }

    @Test
    public void downloadByOrderNos() throws IOException {
        List<String> orderNoList = MyUtils.readTxtFileAsList(basePath + "Orders.txt");
        for (String orderNo : orderNoList) {
            Response response = queryInvoiceInfo(orderNo);
            String ret = response.path("ret");
            int totalCount = response.path("data.totalCount");
            if (ret.equals("1") && totalCount == 1) {
                String invoiceStatus = response.path("data.result[0].invoiceState");
                String invoiceNumber = response.path("data.result[0].invoiceNumber");
                String bizNumber = response.path("data.result[0].bizNumber");
                if (invoiceStatus.equals("开票成功")) {
                    InputStream inputStream = given().param("invoiceNumber", invoiceNumber).get(scmIdc).asInputStream();
                    MyUtils.transferInputStreamToFile(inputStream,
                            new File(basePath + "invoice\\" + "invoice-" + bizNumber + "-" + invoiceNumber + ".pdf"));
                }
            } else {
                System.out.println(orderNo + ": 发票异常");
            }
        }
    }

    public Response queryInvoiceInfo(String orderNO) {
        String url = " https://xx/queryInvoiceList";
        Map<String, String> cookie = new HashMap<>();
        cookie.put("xx", "xx");
        Map<String, String> header = new HashMap<>();
        header.put("xx", "xx");
        Map<String, Object> params = new HashMap<>();
        params.put("currentPage", 1);
        params.put("pageSize", 10);
        params.put("bizNumber", orderNO);
        return given().contentType("application/x-www-form-urlencoded; charset=UTF-8").cookies(cookie).headers(header).params(params).post(url);
    }

MyUtils类

import org.apache.commons.lang3.StringUtils;
import java.io.*;
import java.util.ArrayList;
import java.util.List;

public class MyUtils {
    public static String formatJson(String jsonStr) {
        if (null == jsonStr || "".equals(jsonStr))
            return "";
        StringBuilder sb = new StringBuilder();
        char last = '\0';
        char current = '\0';
        int indent = 0;
        boolean isInQuotationMarks = false;
        for (int i = 0; i < jsonStr.length(); i++) {
            last = current;
            current = jsonStr.charAt(i);
            switch (current) {
                case '"':
                    if (last != '\\') {
                        isInQuotationMarks = !isInQuotationMarks;
                    }
                    sb.append(current);
                    break;
                case '{':
                case '[':
                    sb.append(current);
                    if (!isInQuotationMarks) {
                        sb.append('\n');
                        indent++;
                        addIndentBlank(sb, indent);
                    }
                    break;
                case '}':
                case ']':
                    if (!isInQuotationMarks) {
                        sb.append('\n');
                        indent--;
                        addIndentBlank(sb, indent);
                    }
                    sb.append(current);
                    break;
                case ',':
                    sb.append(current);
                    if (last != '\\' && !isInQuotationMarks) {
                        sb.append('\n');
                        addIndentBlank(sb, indent);
                    }
                    break;
                default:
                    sb.append(current);
            }
        }
        return sb.toString();
    }

    private static void addIndentBlank(StringBuilder sb, int indent) {
        for (int i = 0; i < indent; i++) {
            sb.append('\t');
        }
    }

    // InputStream -> File
    public static void transferInputStreamToFile(InputStream inputStream, File file)
            throws IOException {
        try (FileOutputStream outputStream = new FileOutputStream(file)) {
            int read;
            byte[] bytes = new byte[1024];
            while ((read = inputStream.read(bytes)) != -1) {
                outputStream.write(bytes, 0, read);
            }
        }
    }

    public static List<String> readTxtFileAsList(String filePath) {
        List<String> list = new ArrayList<>();
        try {
            String encoding = "utf-8";
            File file = new File(filePath);
            if (file.isFile() && file.exists()) { //判断文件是否存在
                InputStreamReader read = new InputStreamReader(new FileInputStream(file), encoding);//考虑到编码格式
                BufferedReader bufferedReader = new BufferedReader(read);
                String lineTxt = null;
                while ((lineTxt = bufferedReader.readLine()) != null) {
                    String trimText = lineTxt.trim();
                    if (StringUtils.isNotBlank(trimText)) {
                        list.add(trimText);
                    }
                }
                read.close();
            } else {
                System.out.println("找不到指定的文件");
            }
        } catch (Exception e) {
            System.out.println("读取文件内容出错");
            e.printStackTrace();
        }
        return list;
    }
}