integrated_traffic/src/main/java/com/zcloud/util/ImageUtil.java

package com.zcloud.util;

import cn.hutool.core.codec.Base64;
import cn.hutool.core.util.StrUtil;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.disk.DiskFileItem;
import org.apache.tomcat.util.http.fileupload.IOUtils;
import org.springframework.mock.web.MockMultipartFile;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.multipart.commons.CommonsMultipartFile;

import java.io.*;
import java.net.URL;
import java.nio.file.Files;
import java.util.UUID;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class ImageUtil {

    /**
     * 图片路径层级分隔符
     */
    private static final String separator = "/";

    public static MultipartFile base64ToMultipartFile(String baseImg) {

        //定义一个正则表达式的筛选规则，为了获取图片的类型
        String rgex = "data:image/(.*?);base64";
        if (StrUtil.isBlank(baseImg)) {
            return null;
        }
        String type = getSubUtilSimple(baseImg, rgex);
        //去除base64图片的前缀
        baseImg = baseImg.replaceFirst("data:(.+?);base64,", "");
        byte[] imageByte;
        String fileName = "";
        //把图片转换成二进制
        imageByte = Base64.decode(baseImg.replaceAll(" ", "+"));

        //随机生成图片的名字，同时根据类型结尾
        fileName = UUID.randomUUID().toString() + "." + type;

        InputStream inputStream = new ByteArrayInputStream(imageByte);
        MockMultipartFile mockMultipartFile = null;
        try {
            mockMultipartFile = new MockMultipartFile(fileName, fileName, "", inputStream);
        } catch (IOException e) {
            e.printStackTrace();
        }
        return mockMultipartFile;
    }


    public static String getSubUtilSimple(String soap, String rgex) {
        Pattern pattern = Pattern.compile(rgex);
        Matcher m = pattern.matcher(soap);
        while (m.find()) {
            return m.group(1);
        }
        return "";
    }

    /**
     * 根据url 拉取文件
     * @param url
     * @return
     * @throws Exception
     */
    public static File getFile(String url) throws Exception {
        //对本地文件命名
        String fileName = url.substring(url.lastIndexOf("."),url.length());
        File file = null;

        URL urlfile;
        InputStream inStream = null;
        OutputStream os = null;
        try {
            file = File.createTempFile("fwj_url", fileName);
            //下载
            urlfile = new URL(url);
            inStream = urlfile.openStream();
            os = new FileOutputStream(file);

            int bytesRead = 0;
            byte[] buffer = new byte[8192];
            while ((bytesRead = inStream.read(buffer, 0, 8192)) != -1) {
                os.write(buffer, 0, bytesRead);
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                if (null != os) {
                    os.close();
                }
                if (null != inStream) {
                    inStream.close();
                }

            } catch (Exception e) {
                e.printStackTrace();
            }
        }

        return file;
    }

    /**
     * 根据url获取图片并转换为multipartFile类型
     * @param url
     * @return
     */
    public static MultipartFile getMultipartFile(String url) {
        FileInputStream inputStream = null;
        OutputStream outputStream = null;
        try {
            File file = getFile(url);
            System.out.println(file.toPath());
            FileItem fileItem = new DiskFileItem("formFieldName",//form表单文件控件的名字随便起
                    Files.probeContentType(file.toPath()),//文件类型
                    false, //是否是表单字段
                    file.getName(),//原始文件名
                    (int) file.length(),//Interger的最大值可以存储两部1G的电影
                    file.getParentFile());//文件会在哪个目录创建
            //为DiskFileItem的OutputStream赋值
            inputStream = new FileInputStream(file);
            outputStream = fileItem.getOutputStream();
            IOUtils.copy(inputStream, outputStream);
            return new CommonsMultipartFile(fileItem);
        } catch (Exception e) {
            System.out.println("文件类型转换失败" + e.getMessage());
            return null;
        } finally {
            try {
                if (null != inputStream) {
                    inputStream.close();
                }

                if (null != outputStream) {
                    outputStream.close();
                }
            } catch (IOException e) {
                System.out.println(">>文件流关闭失败" + e.getMessage());
            }
        }
    }
}