manage_invoice/src/main/java/com/jkcredit/invoice/util/WebFileDownLoadUtils.java

package com.jkcredit.invoice.util;

import com.jkcredit.invoice.model.vo.SearchInvoiceResultVo;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Component;
import org.springframework.util.CollectionUtils;
import org.springframework.web.client.RestTemplate;
import org.springframework.web.util.UriComponentsBuilder;

import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.Map;
import java.util.Objects;

/**
 * @description:
 * @author: sunzhaoning
 * @create: 2019-07-12 09:30
 * @version: V1.0
 **/
@Component
@Slf4j
public class WebFileDownLoadUtils {
    
    /**
     * 使用自定义的httpclient的restTemplate
     */
    @Autowired
    private RestTemplate httpClientTemplate;


    /**
     * 下载小文件,采用字节数组的方式,直接将所有返回都放入内存中,容易引发内存溢出
     *
     * @param url
     * @param targetDir
     */
    public void downloadLittleFileToPath(String url, String targetDir, SearchInvoiceResultVo searchInvoiceResult, String batchNumber) {
        downloadLittleFileToPath(url, targetDir, null, searchInvoiceResult, batchNumber);
    }

    /**
     * 下载小文件,直接将所有返回都放入内存中,容易引发内存溢出
     *
     * @param url
     * @param targetDir
     */
    public void downloadLittleFileToPath(String url, String targetDir, Map<String, String> params, SearchInvoiceResultVo searchInvoiceResult, String batchNumber) {
//        Instant now = Instant.now();
        String completeUrl = addGetQueryParam(url, params);
        ResponseEntity<byte[]> rsp = httpClientTemplate.getForEntity(completeUrl, byte[].class);
//        log.info("[下载文件] [状态码] code:{}", rsp.getStatusCode());
        try {
            String path = getAndCreateDownloadDir(targetDir, searchInvoiceResult, batchNumber);
            Files.write(Paths.get(path), Objects.requireNonNull(rsp.getBody(), "未获取到下载文件"));
        } catch (IOException e) {
            log.error("[下载文件] 写入失败:", e);
        }
//        log.info("[下载文件] 完成,耗时:{}", ChronoUnit.MILLIS.between(now, Instant.now()));
    }


    /**
     * 拼接get请求参数
     *
     * @param url
     * @param params
     * @return
     */
    private String addGetQueryParam(String url, Map<String, String> params) {
        UriComponentsBuilder uriComponentsBuilder = UriComponentsBuilder.fromHttpUrl(url);
        if (!CollectionUtils.isEmpty(params)) {
            for (Map.Entry<String, ?> varEntry : params.entrySet()) {
                uriComponentsBuilder.queryParam(varEntry.getKey(), varEntry.getValue());
            }
        }
        return uriComponentsBuilder.build().encode().toString();
    }


    /**
     * 创建或获取下载文件夹的路径
     * <p>
     * //     * @param url
     *
     * @param targetDir
     * @return
     */
    public String getAndCreateDownloadDir(String targetDir, SearchInvoiceResultVo searchInvoiceResult, String batchNumber) throws IOException {
        String filename = searchInvoiceResult.getWaybillNum() + "_" + searchInvoiceResult.getInvoiceCode() + searchInvoiceResult.getInvoiceNum();
        targetDir = targetDir + File.separator + batchNumber;

        if (!Files.exists(Paths.get(targetDir))) {
            Files.createDirectories(Paths.get(targetDir));
        }
        return targetDir + File.separator + filename + ".pdf";
    }
}