Javamail API雖然功能封裝的比較完整，但是要寫一個(gè)能正確顯示復(fù)雜郵件的程序還有很多邏輯和細(xì)節(jié)要處理。下面是我最近做一個(gè)webmail時(shí)整理的Servlet，基本上可以正確的讀取text,HTML,HTML中顯示圖片及附件。在本servlet中也簡(jiǎn)單處理了常見的中文問(wèn)題，包括主題、附件、HTML圖片中文、email Address中文。總體感覺(jué)有兩個(gè)難點(diǎn)：1、附件和網(wǎng)頁(yè)圖片的抓取，需要定位數(shù)節(jié)點(diǎn)nodeid，光用partid是不行的；2、中文分兩種情況Base64和客戶端服務(wù)器端編碼不一致。本程序中實(shí)現(xiàn)了3種displayPart()的方法，具體情況不同結(jié)合使用效率更高。本程序還有一個(gè)未處理的地方就是我在做nodeid的時(shí)候最多算10個(gè)。當(dāng)然還有其他問(wèn)題歡迎指正，來(lái)出是為了給后來(lái)的初學(xué)者作個(gè)參考例子，少走彎路。
1 import java.io.IOException;
2 import java.io.InputStream;
3 import java.io.UnsupportedEncodingException;
4 import java.util.HashMap;
5 import javax.mail.Folder;
6 import javax.mail.Message;
7 import javax.mail.MessagingException;
8 import javax.mail.Multipart;
9 import javax.mail.Part;
10 import javax.mail.Store;
11 import javax.mail.internet.InternetAddress;
12 import javax.mail.internet.MimeUtility;
13 import javax.servlet.ServletException;
14 import javax.servlet.ServletOutputStream;
15 import javax.servlet.http.HttpServletRequest;
16 import javax.servlet.http.HttpServletResponse;
17 import javax.servlet.http.HttpSession;
18 import chunwei.mail.Login;
19 import chunwei.mail.MailUserData;
20 /**
21 * Servlet implementation class for Servlet: MailServlet
22 * Author: luchunwei Email: luchunwei@gmail.com
23 */
24 public class MailNode extends javax.servlet.http.HttpServlet implements javax.servlet.Servlet {
25 private static final long serialVersionUID = 1L;
26 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
27 nodeid="";
28 node="0";
29 currentnodeid=0;
30 url=request.getRequestURL().toString();
31 HttpSession ses=request.getSession();
32 MailUserData mud=(MailUserData)ses.getAttribute("mud");
33 ServletOutputStream out=response.getOutputStream();
34 response.setContentType("text/html;charset=GB2312");
35 int msgid=-1,partid=-1;//msgdi：郵件編號(hào)；partid：MultiPart Message中part的編號(hào)。
36 String partname=null; //圖片或附件的文件名
37 String nodepara=null;//節(jié)點(diǎn)編號(hào)，如1-2-1-0, 他以便層層剝?nèi)?/span>
38 if (request.getParameter("msgid")!=null)
39 msgid=Integer.parseInt(request.getParameter("msgid"));
40 msgidStr="msgid="+msgid;
41 if (request.getParameter("partid")!=null)
42 partid=Integer.parseInt(request.getParameter("partid"));
43 if (request.getParameter("partname")!=null)
44 partname=new String(request.getParameter("partname").getBytes("ISO-8859-1"),"GB2312");
45 if (request.getParameter("node")!=null)
46 nodepara=request.getParameter("node");
47 System.out.println(nodepara);
48 //System.out.println(msgid+":"+partid+":"+partname);
49 if (partname!=null){
50 //displayImages
51 try {
52 displayPart(partname,response,out);
53 } catch (MessagingException e) {
54 e.printStackTrace();
55 } catch (IOException e) {
56 e.printStackTrace();
57 }
58 return;
59 }
60 //--------------------------
61 if (mud==null){
62 Login login=new Login("imap","mail.server.com",-1,"user","password");
63 login.login();
64 if (login.getResult()==1){
65 HttpSession session = request.getSession();
66 session.setMaxInactiveInterval(3600);
67 session.setAttribute("mud",login.getMud());
68 }
69 mud=(MailUserData)ses.getAttribute("mud");
70 }
71 //---------------------------
72 if (mud==null){
73 out.print("<error>Login First(No Session)</error>");
74 } else{
75 //Folder folder=mud.getFolder();
76 try {
77 //------------------------
78 Store store=mud.getStore();
79 Folder folder=store.getFolder("INBOX");
80 folder.open(Folder.READ_ONLY);
81 //------------------------
82 Message m=folder.getMessage(msgid);
83 //if(partid==-1){
84 if (nodepara==null){
85 //if(!imgs.isEmpty())imgs.clear();
86 messageHtml="";
87 attachment="";
88 recipients=getAllgetRecipients(m);
89 out.print(displayMessage(request,m,partid));
90 } else{
91 displayPart(m,nodepara,response,out);
92 }
93 } catch (MessagingException e) {
94 e.printStackTrace();
95 } catch (IOException e) {
96 e.printStackTrace();
97 } catch (Exception e) {
98 e.printStackTrace();
99 }
100 }
101 }
102 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
103 doGet(request,response);
104 }
105 String stdUrl="";
106 String url="";
107 String msgidStr="";
108 String messageHtml="";
109 String attachment="";
110 String recipients="";
111 String nodeid="";
112 int currentnodeid=0;
113 String node="";
114 HashMap<String,Part> imgs=new HashMap<String,Part>();
115 public String displayMessage(HttpServletRequest request,Part p,int partid) throws Exception{
116 //System.out.println("Type:"+p.getContentType());
117 if (currentnodeid==1&&!node.endsWith("0")){
118 nodeid=nodeid.substring(0,(nodeid.length()-2));
119 }
120 node=nodeid+currentnodeid;
121 System.out.println(node);
122 if (p.isMimeType("multipart/*")){
123 nodeid+=currentnodeid+"-";
124 Multipart mp=(Multipart) p.getContent();
125 int cnt=mp.getCount();
126 String mpct=mp.getContentType().toLowerCase();
127 for (int i=0;
128 i<cnt;
129 i++){
130 if (mpct.startsWith("multipart/alternative")&&mp.getBodyPart(i).getContentType().toLowerCase().startsWith("text/plain"))continue;
131 currentnodeid=i;
132 displayMessage(request,mp.getBodyPart(i),i);
133 }
134 }
135 if (p.isMimeType("text/plain")||p.isMimeType("text/html")){
136 if (messageHtml=="") {
137 messageHtml=(String)p.getContent();
138 //System.out.println(messageHtml);
139 } else {
140 messageHtml=messageHtml+"<HR/>"+(String)p.getContent();
141 //System.out.println(messageHtml);
142 }
143 } else if (p.isMimeType("message/rfc822")) {
144 //Nested Message
145 //displayMessage(request,(Part)p.getContent(),partid);
146 } else{
147 if (node.length()>2) node=node.substring(2);
148 System.out.println(node);
149 String disposition=p.getDisposition();
150 //System.out.println("disposition:"+disposition);
151 if (disposition!=null&&disposition.equalsIgnoreCase(Part.ATTACHMENT)){
152 String filename=getFileName(p);
153 //imgs.put(filename,p);
154 //attachment全部放入內(nèi)存，會(huì)造成內(nèi)存膨脹；若及時(shí)清空又造成Back回來(lái)的頁(yè)面訪問(wèn)不到Attachment
155 //attachment+=","+"<a href='"+url+"/"+filename+"?"+msgidStr+"&partid="+partid+"'>"+filename+"</a>";
156 attachment+=","+"<a href='"+url+"/"+filename+"?"+msgidStr+"&node="+node+"'>"+filename+"</a>";
157 //attachment+=","+"<a href='"+url+"/"+filename+"?"+"&partname="+getFileName(p)+"'>"+filename+"</a>";
158 //System.out.println(attachment);
159 } else{
160 //if(disposition!=null&&disposition.equalsIgnoreCase(Part.INLINE)){
161 if (getCid(p)!=null) {
162 //System.out.println("Enter Replace");
163 imgs.put(getFileName(p),p);
164 //String uri=url+"?"+msgidStr+"&partid="+partid;
165 String uri=url+"?"+msgidStr+"&node="+node;
166 //String uri=url+"?"+"&partname="+getFileName(p);
167 String t=messageHtml.substring(messageHtml.indexOf(getCid(p))-1);
168 if (!(t.startsWith("\"")||t.startsWith("\'"))){
169 uri="'"+uri+"'";
170 }
171 messageHtml=messageHtml.replace(getCid(p),uri);
172 //System.out.println("cid:"+getCid(p));
173 //System.out.println(uri);
174 }
175 }
176 }
177 return messageHtml+"attachhncwx="+attachment+recipients;
178 }
179 public void displayPart(Message m,String node,HttpServletResponse response,ServletOutputStream out)
180 throws MessagingException, IOException{
181 Part part = getPart(m,node);
182 String sct = part.getContentType();
183 response.setContentType(sct);
184 outPut(part,out);
185 }
186 private Part getPart(Part m, String nodes) throws NumberFormatException, MessagingException, IOException {
187 if (node==null)return m;
188 String node=nodes.substring(0,1);
189 System.out.println(nodes+" : "+node);
190 int nid=Integer.parseInt(node);
191 if (m.getContent()==null)System.out.print("no content");
192 Part p=((Multipart)m.getContent()).getBodyPart(nid);
193 if (nodes.length()>2)nodes=nodes.substring(2);
194 else {
195 if (nodes.length()==1)nodes="";
196 }
197 if (nodes.length()>0)p=getPart(p,nodes);
198 return p;
199 }
200 public void displayPart(String partname,HttpServletResponse response, ServletOutputStream out) throws MessagingException, IOException{
201 //System.out.println(imgs.keySet()+":"+partname);
202 Part part=imgs.get(partname);
203 String ct=part.getContentType();
204 if (ct!=null) response.setContentType(ct);
205 //=====Start push Stream into out
206 InputStream in=part.getInputStream();
207 ByteArrayOutputStream bos=new ByteArrayOutputStream();
208 byte [] buffer=new byte[8192];
209 int count=0;
210 while ((count=in.read(buffer))>=0) bos.write(buffer,0,count);
211 in .close();
212 try{
213 out.write(bos.toByteArray());
214 out.flush();
215 } catch(Exception e){
216 }
217 out.close();
218 //=====End
219 }
220 public void displayPart(Message m,int partid,HttpServletResponse response, ServletOutputStream out) throws MessagingException, IOException{
221 Multipart mp = (Multipart)m.getContent();
222 Part part = mp.getBodyPart(partid);
223 String sct = part.getContentType();
224 // ContentType ct = new ContentType(sct);
225 response.setContentType(sct);
226 if (sct == null) {
227 out.println("invalid part");
228 return;
229 }
230 //=====Start push Stream into out
231 InputStream in=part.getInputStream();
232 ByteArrayOutputStream bos=new ByteArrayOutputStream();
233 byte [] buffer=new byte[8192];
234 int count=0;
235 while ((count=in.read(buffer))>=0) bos.write(buffer,0,count);
236 in .close();
237 try{
238 out.write(bos.toByteArray());
239 out.flush();
240 } catch(Exception e){
241 }
242 out.close();
243 //=====End
244 }
245 private String getFileName(Part p) throws MessagingException, UnsupportedEncodingException{
246 //System.out.println("filename:");
247 String filename=p.getFileName();
248 if (filename==null)return null;
249 filename=new String(filename.getBytes("ISO-8859-1"),"GB2312");
250 int indexStart=filename.toUpperCase().indexOf("=?GB");
251 if (indexStart>-1){
252 filename=filename.substring(0,indexStart)+MimeUtility.decodeText(filename.substring(indexStart));
253 }
254 return filename;
255 }
256 private String getCid(Part p) throws MessagingException{
257 String cidraw=null,cid=null;
258
259 String [] headers=p.getHeader("Content-id");
260 if (headers!=null && headers.length>0) {
261 cidraw=headers[0];
262 } else{
263 return null;
264 }
265 if (cidraw.startsWith("<")&&cidraw.endsWith(">")) {
266 cid="cid:"+cidraw.substring(1,cidraw.length()-1);
267 } else {
268 cid="cid:"+cidraw;
269 }
270 return cid;
271 }
272 /**
273 * 獲得郵件的收件人，抄送，和密送的地址和姓名，根據(jù)所傳遞的參數(shù)的不同 "to"----收件人 "cc"---抄送人地址 "bcc"---密送人地址
274 * @throws Exception
275 */
276 private String getAllgetRecipients(Message m) throws Exception{
277 return "mailaddrTo=" +getRecipients(m,"TO")
278 +"mailaddrCc="+getRecipients(m,"CC")
279 +"mailaddrBcc="+getRecipients(m,"BCC");
280 }
281 private String getRecipients(Message m,String type) throws Exception {
282 StringBuffer mailaddr = new StringBuffer("");
283 String addtype = type.toUpperCase();
284 InternetAddress[] address = null;
285 if (addtype.equals("TO")) {
286 address = (InternetAddress[]) m.getRecipients(Message.RecipientType.TO);
287 } else if (addtype.equals("CC")) {
288 address = (InternetAddress[]) m.getRecipients(Message.RecipientType.CC);
289 } else {
290 address = (InternetAddress[]) m.getRecipients(Message.RecipientType.BCC);
291 }
292 if (address != null) {
293 for (int i = 0;
294 i < address.length;
295 i++) {
296 String email = address[i].getAddress();
297 if (email == null)
298 email = "";
299 else {
300 email = MimeUtility.decodeText(email);
301 }
302 String personal = address[i].getPersonal();
303 if (personal == null)
304 personal = "";
305 else {
306 personal = MimeUtility.decodeText(personal);
307 }
308 mailaddr.append("\""+personal+"\" ");
309 mailaddr.append("<");
310 mailaddr.append(email);
311 mailaddr.append(">");
312 mailaddr.append(",");
313 }
314 }
315 if (mailaddr.length()>0)mailaddr.deleteCharAt(mailaddr.length()-1);
316 return mailaddr.toString();
317 }
318 private void outPut(Part part,ServletOutputStream out) throws IOException, MessagingException{
319 //=====Start push Stream into out
320 InputStream in=part.getInputStream();
321 ByteArrayOutputStream bos=new ByteArrayOutputStream();
322 byte [] buffer=new byte[8192];
323 int count=0;
324 while ((count=in.read(buffer))>=0) bos.write(buffer,0,count);
325 in .close();
326 try{
327 out.write(bos.toByteArray());
328 out.flush();
329 } catch(Exception e){
330 }
331 out.close();
332 //=====End
333 }
334 }