albert's blog: [Java Mail] Encoding problem

2016/08/05

[Java Mail] Encoding problem

Problem
I am using Java Mail API to sent test mail.
Assume I write email content with Traditional Chinese, all characters are broken.

How-To
We need to set default encoding to 'UTF-8' before send.
Here has the sample code:

import java.io.File;
import java.util.Properties;

import javax.mail.MessagingException;
import javax.mail.internet.MimeMessage;

import org.springframework.core.io.FileSystemResource;
import org.springframework.mail.javamail.JavaMailSenderImpl;
import org.springframework.mail.javamail.MimeMessageHelper;

public class MailTest {

    public static void main(String[] args) {

        Properties props = new Properties();
        props.put("mail.smtp.starttls.enable", "true");

        String host = "smtp.gmail.com";
        int port = 587;
        String userName = "xxx";
        String password = "xxx";

        String mailTo = "xxx@gmail.com";
        String subject = "Hello my friend~";

        JavaMailSenderImpl sender = new JavaMailSenderImpl();
        sender.setJavaMailProperties(props);
        sender.setHost(host);
        sender.setPort(port);
        sender.setUsername(userName);
        sender.setPassword(password);

        // set email default encoding
        sender.setDefaultEncoding("UTF-8");

        String content = "<p>親愛的客戶您好:</p>";
        content += "<p>您的網路申請驗證碼為<font color='red'>12345</font>，僅限會員申請使用，請於收到e-mail <font color='red'>10分鐘內完成驗證，10分鐘後將自動失效</font></p>";
        content += "<p>XXXX敬上</p>";

        MimeMessage message = sender.createMimeMessage();
        try {

            MimeMessageHelper helper;
            helper = new MimeMessageHelper(message, true);
            helper.setTo(mailTo);
            helper.setSubject(subject);

            // true means it is a html format email
            helper.setText(content, true);

     // attachment1
            FileSystemResource panda01 = new FileSystemResource(new File(
                    "D://dropbox//picture//201602011033331.png"));
            helper.addInline("pand01", panda01);

     // attachment2
            FileSystemResource panda02 = new FileSystemResource(new File(
                    "D://dropbox//picture//panda.png"));
            helper.addInline("panda02", panda02);

        } catch (MessagingException e) {
            throw new RuntimeException(e);
        }

 //sent mail
        sender.send(message);
    }
}