DouKaku?

import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.Reader;
import java.io.StringWriter;
import java.util.HashMap;
import java.util.Properties;
import java.util.StringTokenizer;
import javax.mail.MessagingException;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;

public class MailSender {
    private static final String encoding = "ISO-2022-JP";

    public static void main(String[] args) throws Exception {
        // テンプレートと差込データの読み込み
        String template = readFile(args[0]);
        HashMap vars = readVars(args[1]);
        // テンプレートを使用したメールの整形
        TemplateFormatter formatter = new TemplateFormatter();
        String mail = formatter.format(template, vars);
        // メールの送信
        sendMail(mail);
    }
    
    public static String readFile(String filename) throws IOException {
        Reader in = new InputStreamReader(new FileInputStream(filename), "UTF-8");
        StringWriter out = new StringWriter();
        for (int c = in.read(); c >=0; c = in.read()) out.write(c);
        in.close();
        out.close();
        return out.toString();
    }
    
    public static HashMap readVars(String filename) throws IOException {
        HashMap<String,String> result = new HashMap<String,String>();
        BufferedReader in = new BufferedReader(
                new InputStreamReader(
                        new FileInputStream(filename), "UTF-8"));
        for (String s = in.readLine(); s != null; s = in.readLine()) {
            if (s.trim().startsWith("#")) continue;
            int off = s.indexOf(":");
            if (off <= 0) continue;
            result.put(s.substring(0,off).trim(), s.substring(off+1).trim());
        }
        in.close();
        return result;
    }
    
    public static void sendMail(String mail) throws MessagingException, IOException {
        Properties props = System.getProperties();
        Session session = Session.getDefaultInstance(props);
        MimeMessage message = new MimeMessage(session);
        StringTokenizer st = new StringTokenizer(mail, "\n");
        while (st.hasMoreTokens()) {
            String s = st.nextToken();
            int off = s.indexOf(":");
            if (off < 0) break;
            String header = s.substring(0,off).trim();
            String value = s.substring(off+1);
            if (header.equalsIgnoreCase("subject")) {
                message.setSubject(value, encoding);
            } else if (header.equalsIgnoreCase("to")) {
                message.setRecipients(MimeMessage.RecipientType.TO, value);
            } else if (header.equalsIgnoreCase("from")) {
                message.setFrom(new InternetAddress(value));
            } else {
                message.setHeader(header, value);
            }
        }
        StringBuffer body = new StringBuffer();
        while (st.hasMoreTokens()) {
            body.append(st.nextToken()).append("\n");
        }
        message.setText(body.toString(), encoding);
//      Transport.send(message);        // 実際に送信する場合
        message.writeTo(System.out);    // 課題にあわせて標準出力に
    }
}

class TemplateFormatter {
    private String prefix = "[[";
    private String postfix = "]]";
    public TemplateFormatter() {}
    public TemplateFormatter(String prefix, String postfix) {
        this.prefix = prefix;
        this.postfix = postfix;
    }
    public String format(String tempate, HashMap<String,String> vars) {
        StringBuffer result = new StringBuffer(tempate);
        for (String key : vars.keySet()) {
            String element = prefix + key + postfix;
            while (result.indexOf(element) >= 0) {
                int off = result.indexOf(element);
                result.replace(off, off+element.length(), vars.get(key));
            }
        }
        return result.toString();
    }
}