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java发送邮件代码

import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;
import com.unicloud.uplus.client.oss.OSSClient;
import com.unicloud.uplus.core.protocol.TransferContext;
import com.unicloud.uplus.di.data.trans.steps.custom.mail.Attachment;
import org.apache.commons.collections.CollectionUtils;
import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.env.Environment;
import org.springframework.stereotype.Component;

import javax.activation.DataHandler;
import javax.activation.DataSource;
import javax.activation.FileDataSource;
import javax.activation.MimetypesFileTypeMap;
import javax.annotation.PostConstruct;
import javax.mail.*;
import javax.mail.internet.*;
import javax.mail.util.ByteArrayDataSource;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Properties;

/**
 * @Author wangjinpeng
 * @Description
 * @Date 2021/7/9
 * @Version 1.0
 */
@Component
public class MailUtil {
    private static Logger logger = LoggerFactory.getLogger(MailUtil.class);

    @Autowired
    private Environment env;

    private static String host = "";
    private static String user = "";
    private static String pwd = "";
    private static String authCode = "";
    private static String from = "";


    @PostConstruct
    public void config() {
        host = env.getProperty("mail.host");
        user = env.getProperty("mail.user");
        pwd = env.getProperty("mail.pwd");
        authCode = env.getProperty("mail.authCode");
        from = env.getProperty("mail.from");
    }

    /**
     * 后加的防止题目过长并且进行全局定义
     */
    static {
        System.setProperty("mail.mime.splitlongparameters", "false");
        System.setProperty("mail.mime.charset", "UTF-8");
    }

    public static void send(String to,String cc, String subject, String content, List<Attachment> attachmentList){
        Properties props = new Properties();

        // 设置发送邮件的邮件服务器的属性（这里使用网易的smtp服务器）
        props.put("mail.smtp.host", host);
        // 需要经过授权，也就是有户名和密码的校验，这样才能通过验证（一定要有这一条）
        props.put("mail.smtp.auth", "true");

        // 用刚刚设置好的props对象构建一个session
        Session session = Session.getDefaultInstance(props);

        // 有了这句便可以在发送邮件的过程中在console处显示过程信息，供调试使
        // 用（你可以在控制台（console)上看到发送邮件的过程）
        session.setDebug(true);

        // 用session为参数定义消息对象
        MimeMessage message = new MimeMessage(session);
        try {
            // 加载发件人地址
            message.setFrom(new InternetAddress(from));
            // 加载收件人地址
            List<String> toList = Arrays.asList(to.split(","));
            if(CollectionUtils.isNotEmpty(toList)){
                for(String s : toList){
                    message.addRecipient(Message.RecipientType.TO, new InternetAddress(s));
                }
            }
            // 加载抄送地址
            List<String> ccList = Arrays.asList(cc.split(","));
            if(CollectionUtils.isNotEmpty(ccList)){
                for(String s : ccList){
                    message.addRecipient(Message.RecipientType.CC, new InternetAddress(s));
                }
            }
            // 加载标题
            message.setSubject(subject);
            // 向multipart对象中添加邮件的各个部分内容，包括文本内容和附件
            Multipart multipart = new MimeMultipart();
            // 设置邮件的文本内容
            BodyPart contentPart = new MimeBodyPart();
            contentPart.setText(content);
            multipart.addBodyPart(contentPart);
            List<File> fileList = new ArrayList<>();
            // 添加附件
            if(CollectionUtils.isNotEmpty(attachmentList)){
                BodyPart messageBodyPart = null;
                for (Attachment attachment : attachmentList){
                    messageBodyPart = new MimeBodyPart();
                    String fileId = attachment.getUri().substring(attachment.getUri().lastIndexOf("/")+1, attachment.getUri().length());
                    String filePath = System.getProperty("java.io.tmpdir") + System.getProperty("file.separator");
                    File file = OSSClient.download(fileId,filePath);
                    fileList.add(file);
                    String fileName = file.getName();
//                    String contentType = new MimetypesFileTypeMap().getContentType(file);
//                    DataSource source = new ByteArrayDataSource(new ByteArrayInputStream(OSSClient.download(fileId)),contentType);
                    DataHandler dataHandler = new DataHandler(new FileDataSource(file));
                    // 添加附件的内容
                    messageBodyPart.setDataHandler(dataHandler);
                    messageBodyPart.setFileName(MimeUtility.encodeText(fileName));
                    multipart.addBodyPart(messageBodyPart);
                }
            }
            // 将multipart对象放到message中
            message.setContent(multipart);
            // 保存邮件
            message.saveChanges();
            // 发送邮件
            Transport transport = session.getTransport("smtp");
            // 连接服务器的邮箱
            transport.connect(host, user, authCode);
            // 把邮件发送出去
            transport.sendMessage(message, message.getAllRecipients());
            transport.close();
            if(CollectionUtils.isNotEmpty(fileList)){
                fileList.forEach((file) -> {
                    file.delete();
                });
            }
        } catch (Exception e) {
            e.printStackTrace();
            logger.error("发送邮件失败！",e);
        }
    }

}