第七讲：解析邮件内容
一、JavaMail解析邮件内容的流程
二、解析邮件内容
2.1 解析普通邮件内容
如果Message.getContentType方法返回的MIME类型为"text/*"则表示邮件内容为文本内容，此时直接调用Message.getContent方法把邮件内容保存了一个String对象中输出给浏览器即可。但是现实邮件中会有HTML格式的邮件内容时，邮件发送程序为了防止有些邮件阅读软件不能显示处理HTML格式的数据，通常都会用两类型分别为"text/plain"和"text/html"的MIME消息封装HTML代码。因此对于这两种类型要通过判断之后方可显示。
下面使用例子来进行判断：
当含有"text/plain"和"text/html"中时使用Message.getContentType返回的类型为"multipart/alternative"
public class Demo1 extends HttpServlet {
String host = "pop3.163.com";
String protocol = "pop3";
String username = "XXX";
String password = "XXX";
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=gb2312");
PrintWriter out = response.getWriter();
Properties props = new Properties();
props.setProperty("mail.store.protocol", protocol);
props.setProperty("mail.pop3.host", host);
javax.mail.Session session = javax.mail.Session.getInstance(props);
session.setDebug(false);
try {
Store store = session.getStore(protocol);
store.connect(host, username, password);
Folder folder = store.getFolder("inbox");
folder.open(Folder.READ_WRITE);
Message[] msgs = folder.getMessages();
for(int i=0; i< msgs.length; i++){
String from = msgs[i].getFrom()[0].toString();
String subject = msgs[i].getSubject();
out.print("第"+(i+1)+"封邮件<br/>");
out.print("发件人："+from);
out.print("主题："+subject);
/**
* 检查是否是"multipart/alternative"类型，
* 如果是取出其中的"text/html"类型的消息
*/
if(msgs[i].isMimeType("multipart/alternative")){
Multipart mp = (Multipart)msgs[i].getContent();
int bodynum = mp.getCount();
for(int j=0; j<bodynum; j++){
if(mp.getBodyPart(j).isMimeType("text/html")){
String content = (String)mp.getBodyPart(j).getContent();
out.print("邮件内容："+content+"<br/>");
out.print("-------------------------------<br/>");
}
else{
out.print("不支持的邮件类型<br/>");
}
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
}2.2 解析“multipart/related”类型的邮件public class Demo2 extends HttpServlet {
String host = "pop3.163.com";
String protocol = "pop3";
String username = "XXX";
String password = "XXX";
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
ServletOutputStream out = response.getOutputStream();
Properties props = new Properties();
props.setProperty("mail.store.protocol", protocol);
props.setProperty("mail.pop3.host", host);
javax.mail.Session session = javax.mail.Session.getInstance(props);
session.setDebug(false);
try {
Store store = session.getStore(protocol);
store.connect(host, username, password);
Folder folder = store.getFolder("inbox");
folder.open(Folder.READ_WRITE);
/**
* 假设取得第一封邮件是"multipart/related"
* 则直接进行处理
*/
Message msg = folder.getMessage(0);
response.setContentType("message/rfc822");
msg.writeTo(System.out);
msg.writeTo(out);
} catch (Exception e) {
e.printStackTrace();
}
}
}2.3 使用IE解析正文需要注意的问题
<%@ page language="java" import="java.util.*" import="javax.mail.*" pageEncoding="ISO-8859-1"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
String host = "pop3.163.com";
String protocol = "pop3";
String username = "XXX";
String password = "XXX";
Properties props = new Properties();
props.setProperty("mail.store.protocol", protocol);
props.setProperty("mail.pop3.host", host);
javax.mail.Session mailSession = javax.mail.Session.getInstance(props);
mailSession.setDebug(true);
try {
Store store = mailSession.getStore(protocol);
store.connect(host, username, password);
Folder folder = store.getFolder("inbox");
folder.open(Folder.READ_WRITE);
session.setAttribute("folder", folder);
} catch (Exception e) {
e.printStackTrace();
}
%>
<frameset>
<frame src="/receivedMail/displayHeader" scrolling="no">
<frame src="/receivedMail/displayContent" scrolling="no">
</frameset>
2.4 解析邮件附件在Web应用中解析包含附件的邮件时，只需要从Message对象中解析出保存附件数据的BodyPart对象，然后从BodyPart对象中得到附件的输入流、附件的MIME类型和附件的文件名，并且这些信息输出给IE浏览器。浏览器收到信息后，会根据数据的MIME类型弹出相应的对话框提示用户下载或打开附件。
public class Demo3 extends HttpServlet {
String host = "pop3.163.com";
String protocol = "pop3";
String username = "XXX";
String password = "XXX";
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=gb2312");
PrintWriter out = response.getWriter();
Properties props = new Properties();
props.setProperty("mail.store.protocol", protocol);
props.setProperty("mail.pop3.host", host);
javax.mail.Session mailSession = javax.mail.Session.getInstance(props);
mailSession.setDebug(false);
try {
Store store = mailSession.getStore(protocol);
store.connect(host, username, password);
Folder folder = store.getFolder("inbox");
folder.open(Folder.READ_WRITE);
Message msg1 = folder.getMessage(1);
request.getSession().setAttribute("message", msg1);
String from = msg1.getFrom()[0].toString();
String subject = msg1.getSubject();
String sendDate = DateFormat.getInstance().format(msg1.getSentDate());
out.print("发件人："+from+"<br/>");
out.print("主题："+subject+"<br/>");
out.print("发件日期："+sendDate+"<br/>");
Multipart mp = (Multipart)msg1.getContent();
for(int i=0; i<mp.getCount(); i++){
BodyPart bp =mp.getBodyPart(i);
if(bp.getDisposition()!=null){
String fileName = bp.getFileName();
if(fileName.startsWith("=?")){
fileName = MimeUtility.decodeText(fileName);
}
out.print("附件：");
out.print("<a href=\\receivedMail\\HandleAttach?>"+
"bodynum="+ i +"&&filename= " + fileName + "</a><br/>");
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
}下面的文件是在用户点击上述的连接时就会自动的现在文件：public class HandleAttach extends HttpServlet {
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html");
HttpSession session = request.getSession();
ServletOutputStream out = response.getOutputStream();
int bodynum = Integer.parseInt(request.getParameter("bodynum"));
String fileName = request.getParameter("filename");
Message message = (Message)session.getAttribute("message");
try {
response.setHeader("Content-Disposition", "attachment;filename="+fileName);
Multipart mp = (Multipart)message.getContent();
BodyPart bp = mp.getBodyPart(bodynum);
InputStream is = bp.getInputStream();
int c=0;
if((c = is.read())!= -1){
out.write(c);
}
} catch (Exception e) {
e.printStackTrace();
}
}
}原文：http://blog.csdn.net/wenwen1538/article/details/25241535