package com.template.common.utils;


import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileItemFactory;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.springframework.http.MediaType;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.multipart.commons.CommonsMultipartFile;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

/**
 * @Author: binguo
 * @Date: 2023/12/27 星期三 11:08
 * @Description: com.template.common.utils
 * @Version: 1.0
 */
public class FileUtils {


    /**
     * 获取封装得MultipartFile
     *
     * @param inputStream inputStream
     * @return MultipartFile
     */
    public static MultipartFile getMultipartFile(InputStream inputStream, String fileName) {
        FileItem fileItem = createFileItem(inputStream, fileName);
        //CommonsMultipartFile是feign对multipartFile的封装，但是要FileItem类对象
        return new CommonsMultipartFile(fileItem);
    }
    /**
     * FileItem类对象创建
     *
     * @param inputStream inputStream
     * @param fileName    fileName
     * @return FileItem
     */
    public static FileItem createFileItem(InputStream inputStream, String fileName) {
        FileItemFactory factory = new DiskFileItemFactory(16, null);
        String textFieldName = "file";
        FileItem item = factory.createItem(textFieldName, MediaType.MULTIPART_FORM_DATA_VALUE, true, fileName);
        int bytesRead = 0;
        byte[] buffer = new byte[10 * 1024 * 1024];
        OutputStream os = null;
        //使用输出流输出输入流的字节
        try {
            os = item.getOutputStream();
            while ((bytesRead = inputStream.read(buffer, 0, 8192)) != -1) {
                os.write(buffer, 0, bytesRead);
            }
            inputStream.close();
        } catch (IOException e) {
            throw new IllegalArgumentException("文件上传失败");
        } finally {
            if (os != null) {
                try {
                    os.close();
                } catch (IOException e) {

                }
            }
            if (inputStream != null) {
                try {
                    inputStream.close();
                } catch (IOException e) {
                }
            }
        }

        return item;
    }
}
