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java web 实现上传下载

 
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jsp页面代码：

[html] view plaincopyprint?
  1. <%@pagelanguage="java"contentType="text/html;charset=UTF-8"
  2. pageEncoding="UTF-8"%>
  3. <%@tagliburi="http://java.sun.com/jsp/jstl/core"prefix="c"%>
  4. <!DOCTYPEhtmlPUBLIC"-//W3C//DTDHTML4.01Transitional//EN""http://www.w3.org/TR/html4/loose.dtd">
  5. <html>
  6. <head>
  7. <metahttp-equiv="Content-Type"content="text/html;charset=UTF-8">
  8. <title>上传文件</title>
  9. </head>
  10. <body>
  11. <fontcolor="red"size="3px"><b>${error}</b></font>
  12. <tableborder="1"width="60%">
  13. <tr>
  14. <th>用户名</th>
  15. <th>性别</th>
  16. <th>头像</th>
  17. <th>IP地址</th>
  18. <th>上传文件名</th>
  19. <th>操作</th>
  20. </tr>
  21. <c:forEachitems="${list}"var="user">
  22. <tr>
  23. <td>${user.name}</td>
  24. <td>${user.sex==true?"男":"女"}</td>
  25. <td><imgsrc="${user.pic}"height="120"></td>
  26. <td>${user.ip}</td>
  27. <td>${user.fileName}</td>
  28. <td><ahref="/upload?mode=download&id=${user.id}">下载</a></td>
  29. </tr>
  30. </c:forEach>
  31. </table>
  32. <formaction="/upload?mode=upload"method="post">
  33. <inputtype="submit"value="去上传..."/>
  34. </form>
  35. </body>
  36. </html>

jsp页面代码：

[html] view plaincopyprint?
  1. <%@pagelanguage="java"contentType="text/html;charset=UTF-8"
  2. pageEncoding="UTF-8"%>
  3. <%@tagliburi="http://java.sun.com/jsp/jstl/core"prefix="c"%>
  4. <!DOCTYPEhtmlPUBLIC"-//W3C//DTDHTML4.01Transitional//EN""http://www.w3.org/TR/html4/loose.dtd">
  5. <html>
  6. <head>
  7. <metahttp-equiv="Content-Type"content="text/html;charset=UTF-8">
  8. <title>上传文件</title>
  9. <scripttype="text/javascript">
  10. vartag=true;
  11. functiongo(){
  12. if(tag){
  13. document.forms[0].submit();
  14. tag=false;
  15. }else{
  16. alert("正在提交中，请勿重复提交请求……");
  17. }
  18. }
  19. </script>
  20. </head>
  21. <body>
  22. <fontcolor="red"size="3px"><b>${error}</b></font>
  23. <formaction="/upload?mode=add"method="post"enctype="multipart/form-data">
  24. <inputtype="hidden"name="randomName"value="${randomName}"/>
  25. <inputtype="hidden"name="randomValue"value="${randomValue}"/>
  26. <table>
  27. <tr>
  28. <td>用户名：</td>
  29. <td><inputtype="text"name="name"/></td>
  30. </tr>
  31. <tr>
  32. <td>性 别：</td>
  33. <td><inputtype="radio"name="sex"value="true"/>男
  34. <inputtype="radio"name="sex"value="false"/>女
  35. </td>
  36. </tr>
  37. <tr>
  38. <td>头 像：</td>
  39. <td><inputtype="file"name="pic"/></td>
  40. </tr>
  41. <!--<tr>
  42. <td>IP地址：</td>
  43. <td><inputtype="text"name="ip"/></td>
  44. </tr>-->
  45. <tr>
  46. <td>文件名：</td>
  47. <td><inputtype="file"name="fileName"/></td>
  48. </tr>
  49. <tr>
  50. <!--<tdcolspan="2"align="center"><inputtype="button"value="提交"onclick="go()"/></td>-->
  51. <tdcolspan="2"align="center"><inputtype="submit"value="提交""/>
  52. </tr>
  53. </table>
  54. </form>
  55. </body>
  56. </html>
User .java代码：

[java] view plaincopyprint?
  1. packagecn.itcast.cd.domain;
  3. publicclassUser{
  4. privateLongid;
  5. privateStringname;
  6. privateBooleansex;
  7. privateStringpic;
  8. privateStringip;
  9. privateStringfileName;
  10. privateStringfilePath;
  11. privatelongfileSize;
  13. publicStringgetName(){
  14. returnname;
  15. }
  17. publicvoidsetName(Stringname){
  18. this.name=name;
  19. }
  21. publicBooleangetSex(){
  22. returnsex;
  23. }
  25. publicvoidsetSex(Booleansex){
  26. this.sex=sex;
  27. }
  29. publicStringgetFileName(){
  30. returnfileName;
  31. }
  33. publicvoidsetFileName(StringfileName){
  34. this.fileName=fileName;
  35. }
  37. publicStringgetFilePath(){
  38. returnfilePath;
  39. }
  41. publicvoidsetFilePath(StringfilePath){
  42. this.filePath=filePath;
  43. }
  45. publicLonggetId(){
  46. returnid;
  47. }
  49. publicvoidsetId(Longid){
  50. this.id=id;
  51. }
  53. publicStringgetIp(){
  54. returnip;
  55. }
  57. publicvoidsetIp(Stringip){
  58. this.ip=ip;
  59. }
  61. publicStringgetPic(){
  62. returnpic;
  63. }
  65. publicvoidsetPic(Stringpic){
  66. this.pic=pic;
  67. }
  69. publiclonggetFileSize(){
  70. returnfileSize;
  71. }
  73. publicvoidsetFileSize(longfileSize){
  74. this.fileSize=fileSize;
  75. }
  77. @Override
  78. publicStringtoString(){
  79. return"User[id="+id+",name="+name+",sex="+sex+",pic="
  80. +pic+",ip="+ip+",fileName="+fileName+",filePath="
  81. +filePath+",fileSize="+fileSize+"]";
  82. }
  83. }
IUserDAO 接口：
[java] view plaincopyprint?
  1. packagecn.itcast.cd.dao;
  3. importjava.util.List;
  5. importcn.itcast.cd.domain.User;
  7. publicinterfaceIUserDAO{
  8. voidadd(Useruser);
  9. List<User>list();
  10. Userget(Longid);
  11. }
BaseDao .java代码：

[java] view plaincopyprint?

  1. packagecn.itcast.cd.daoImpl;
  3. importjava.sql.SQLException;
  5. importorg.apache.commons.dbutils.QueryRunner;
  6. importorg.apache.commons.dbutils.ResultSetHandler;
  8. importcn.itcast.cd.Utils.Utils;
  10. publicclassBaseDao{
  11. //使用DbUtils中的QueryRunner对象.
  12. privateQueryRunnerqueryRunner=newQueryRunner(Utils.getDataSource());
  13. /*
  14. *执行修改
  15. */
  16. publicvoidexeUpdate(Stringsql,Object...params){
  17. try{
  18. queryRunner.update(sql,params);
  19. }catch(SQLExceptione){
  20. e.printStackTrace();
  21. }
  22. }
  24. /*
  25. *执行查询
  26. */
  27. public<T>TexeQuery(Stringsql,ResultSetHandler<T>rsh,Object...params){
  28. try{
  29. returnqueryRunner.query(sql,rsh,params);
  30. }catch(SQLExceptione){
  31. e.printStackTrace();
  32. }
  33. returnnull;
  34. }
  35. }

UserDAOImpl.java实现类：
[java] view plaincopyprint?

  1. packagecn.itcast.cd.daoImpl;
  3. importjava.util.List;
  5. importorg.apache.commons.dbutils.handlers.BeanHandler;
  6. importorg.apache.commons.dbutils.handlers.BeanListHandler;
  8. importcn.itcast.cd.dao.IUserDAO;
  9. importcn.itcast.cd.domain.User;
  11. publicclassUserDAOImplextendsBaseDaoimplementsIUserDAO{
  13. @Override
  14. publicvoidadd(Useruser){
  15. Stringsql="insertintouservalues(null,?,?,?,?,?,?)";
  16. Object[]params={user.getName(),user.getSex(),user.getPic(),user.getIp(),
  17. user.getFileName(),user.getFilePath()};
  18. exeUpdate(sql,params);
  19. }
  21. @Override
  22. publicList<User>list(){
  23. Stringsql="select*fromuser";
  24. returnexeQuery(sql,newBeanListHandler<User>(User.class));
  25. }
  27. @Override
  28. publicUserget(Longid){
  29. Stringsql="select*fromuserwhereid=?";
  30. returnexeQuery(sql,newBeanHandler<User>(User.class),id);
  31. }
  32. }

BaseServlet.java代码：

[java] view plaincopyprint?

  1. packagecn.itcast.cd.servlet;
  3. importjava.io.IOException;
  4. importjava.lang.reflect.Method;
  6. importjavax.servlet.ServletException;
  7. importjavax.servlet.http.HttpServlet;
  8. importjavax.servlet.http.HttpServletRequest;
  9. importjavax.servlet.http.HttpServletResponse;
  11. importorg.apache.commons.lang3.StringUtils;
  13. publicclassBaseServletextendsHttpServlet{
  15. privatestaticfinallongserialVersionUID=1L;
  17. @Override
  18. protectedvoidservice(HttpServletRequestreq,HttpServletResponseresp)
  19. throwsServletException,IOException{
  20. req.setCharacterEncoding("UTF-8");
  21. Stringmode=req.getParameter("mode");
  23. if(StringUtils.isNotBlank(mode)){
  24. try{
  25. Methodmethod=this.getClass().getMethod(mode,
  26. HttpServletRequest.class,HttpServletResponse.class);
  27. method.invoke(this,req,resp);
  28. }catch(Exceptione){
  29. e.printStackTrace();
  30. }
  31. }else{
  32. doMethod(req,resp);//默认调用
  33. }
  34. }
  36. protectedvoiddoMethod(HttpServletRequestreq,HttpServletResponseresp){
  38. }
  39. }

MyHttpServletRequest.java类：

[java] view plaincopyprint?

  1. packagecn.itcast.cd.servlet;
  3. importjava.io.File;
  4. importjava.io.UnsupportedEncodingException;
  5. importjava.util.HashMap;
  6. importjava.util.List;
  7. importjava.util.Map;
  8. importjava.util.UUID;
  10. importjavax.servlet.http.HttpServletRequest;
  11. importjavax.servlet.http.HttpServletRequestWrapper;
  13. importorg.apache.commons.fileupload.FileItem;
  14. importorg.apache.commons.fileupload.FileItemFactory;
  15. importorg.apache.commons.fileupload.FileUploadBase.SizeLimitExceededException;
  16. importorg.apache.commons.fileupload.FileUploadException;
  17. importorg.apache.commons.fileupload.disk.DiskFileItemFactory;
  18. importorg.apache.commons.fileupload.servlet.ServletFileUpload;
  19. importorg.apache.commons.io.FilenameUtils;
  21. importcn.itcast.cd.Utils.MyException;
  22. importcn.itcast.cd.Utils.UploadFileInfo;
  24. publicclassMyHttpServletRequestextendsHttpServletRequestWrapper{
  25. //装在普通表单元素的map
  26. privateMap<String,String>formFiledMap=newHashMap<String,String>();
  28. //装在上传表单元素的Map
  29. privateMap<String,FileItem>uploadFieldMap=newHashMap<String,FileItem>();
  31. BooleanisMultipartContent=false;
  33. publicMyHttpServletRequest(HttpServletRequestrequest){
  34. super(request);
  35. //检查是否是文件上传请求
  36. isMultipartContent=ServletFileUpload.isMultipartContent(request);
  37. if(isMultipartContent){
  38. //创建工程，设置上传最大的内存空间和临时文件存放位置.
  39. FileItemFactoryfactory=newDiskFileItemFactory(1024*1024*10,
  40. newFile("D:/tmp"));
  41. ServletFileUploadfileUpload=newServletFileUpload(factory);
  42. fileUpload.setFileSizeMax(1024*1024);//设置单个文件上传的最大值为1M.
  43. fileUpload.setSizeMax(1024*1024*5);//设置整个表单的文件上传最大值为5M.
  44. try{
  45. List<FileItem>fileItems=fileUpload.parseRequest(request);
  46. for(FileItemfileItem:fileItems){
  47. //是否是普通表单元素，即type不为file的表单元素
  48. if(fileItem.isFormField()){
  49. formFiledMap.put(fileItem.getFieldName(),
  50. fileItem.getString("UTF-8"));
  51. }else{
  52. if(fileItem.getSize()>0){
  53. uploadFieldMap.put(fileItem.getFieldName(),
  54. fileItem);
  55. }
  56. }
  57. }
  58. }catch(SizeLimitExceededExceptione){
  59. thrownewMyException("上传文件的大小超过限制！");
  60. }catch(FileUploadExceptione){
  61. e.printStackTrace();
  62. }catch(UnsupportedEncodingExceptione){
  63. e.printStackTrace();
  64. }
  65. }
  66. }
  68. //包装原来的方法
  69. @Override
  70. publicStringgetParameter(Stringname){
  71. //是上传文件的表单，要得到参数值，直接根据name，取存在map中的值.
  72. if(isMultipartContent){
  73. returnformFiledMap.get(name);
  74. }else{
  75. returnsuper.getParameter(name);
  76. }
  77. }
  79. //已经将Map修改了，覆盖原来的方法
  80. @Override
  81. publicMapgetParameterMap(){
  82. if(isMultipartContent){
  83. returnformFiledMap;
  84. }else{
  85. returnsuper.getParameterMap();
  86. }
  87. }
  89. /**
  90. *上传表单中指定表单元素中的文件.
  91. *
  92. *@paramformFieldName
  93. *表单中元素的名称
  94. *@paramtagPath
  95. *上传的目标目录，即服务器上存放上传文件的目录.
  96. *
  97. *@return由于上传成功后，我们需要将上传的文件名和文件地址存放到数据库，
  98. *也即需要返回给Servlet上传的文件信息，故将文件信息封装成一个对象返回.
  99. *
  100. */
  101. publicUploadFileInfoupload(StringformFieldName,StringtagPath){
  102. FileItemfileItem=uploadFieldMap.get(formFieldName);
  103. if(fileItem!=null){
  104. //得到文件名fileItem.getName()有些浏览器可能得到的是全路径，而这里只需要文件名
  105. StringsrcFileName=FilenameUtils.getName(fileItem.getName());
  106. longfileSize=fileItem.getSize();
  108. //不同的用户可能上传相同的文件名，不处理就被覆盖，所以这里需要用唯一标示进行文件区分.
  109. StringtagFilePath=tagPath+"/"+UUID.randomUUID().toString()+"."+FilenameUtils.getExtension(srcFileName);
  111. if(!tagPath.startsWith("/")){
  112. tagPath="/"+tagPath;
  113. }
  115. //判断目录是否存在，不存在就创建
  116. Filedir=newFile(getSession().getServletContext().getRealPath("/")+tagPath);
  117. if(!dir.exists()){
  118. dir.mkdirs();
  119. }
  121. //写到指定目录
  122. try{
  123. fileItem.write(newFile(getSession().getServletContext().getRealPath("/"),tagFilePath));
  124. }catch(Exceptione){
  125. e.printStackTrace();
  126. }
  127. returnnewUploadFileInfo(srcFileName,tagFilePath,fileSize);
  128. }
  129. returnnull;
  130. }
  131. }

UploadServlet.java类：

[java] view plaincopyprint?

  1. packagecn.itcast.cd.servlet;
  3. importjava.io.BufferedInputStream;
  4. importjava.io.BufferedOutputStream;
  5. importjava.io.File;
  6. importjava.io.FileInputStream;
  7. importjava.io.IOException;
  8. importjava.io.UnsupportedEncodingException;
  9. importjava.net.URLEncoder;
  10. importjava.util.List;
  11. importjava.util.UUID;
  13. importjavax.servlet.ServletException;
  14. importjavax.servlet.http.HttpServletRequest;
  15. importjavax.servlet.http.HttpServletResponse;
  17. importorg.apache.catalina.startup.SetAllPropertiesRule;
  18. importorg.apache.commons.lang3.StringUtils;
  20. importcn.itcast.cd.Utils.MyException;
  21. importcn.itcast.cd.Utils.UploadFileInfo;
  22. importcn.itcast.cd.dao.IUserDAO;
  23. importcn.itcast.cd.daoImpl.UserDAOImpl;
  24. importcn.itcast.cd.domain.User;
  26. /**
  27. *ServletimplementationclassUploadServlet
  28. */
  29. publicclassUploadServletextendsBaseServlet{
  30. privatestaticfinallongserialVersionUID=1L;
  32. IUserDAOdao=null;
  34. @Override
  35. publicvoidinit()throwsServletException{
  36. dao=newUserDAOImpl();
  37. }
  39. publicvoidadd(HttpServletRequestrequest,HttpServletResponseresponse)
  40. throwsInterruptedException{
  41. //request不能接收上传文件的表单参数，返回全部为null，所以用MyHttpServletRequest类进行包装，单独处理.
  43. //Thread.sleep(1000);
  45. MyHttpServletRequestmyRequest=null;
  46. try{
  47. myRequest=newMyHttpServletRequest(request);
  48. }catch(MyExceptione){//捕捉自定义异常，提示用户上传文件的大小限制
  49. request.setAttribute("error",e.getMessage());
  50. upload(request,response);
  51. return;
  52. }
  54. /*
  55. *从页面得到标示信息，由于是文件上传的请求，必须用myRequest
  56. */
  57. StringrandomName=myRequest.getParameter("randomName");
  58. StringrandomValue=myRequest.getParameter("randomValue");
  59. //session中的标示.
  60. StringrandomValueInSession=(String)myRequest.getSession().getAttribute(randomName);
  62. //System.out.println(randomName+""+randomValue+""+randomValueInSession);
  64. if(StringUtils.isNotBlank(randomValueInSession)&&
  65. StringUtils.isNotBlank(randomValue)&&StringUtils.isNotBlank(randomName)
  66. &&randomValueInSession.equals(randomValue)){
  67. //接收普通表单元素的参数信息
  68. Stringname=myRequest.getParameter("name");
  69. Stringsex=myRequest.getParameter("sex");
  71. //封装对象
  72. Useruser=newUser();
  73. user.setName(name);
  74. user.setSex(Boolean.parseBoolean(sex));
  76. Stringip=request.getRemoteAddr();
  77. user.setIp(ip);
  79. //上传头像信息
  80. UploadFileInfopicInfo=myRequest.upload("pic","/headPic");
  81. if(picInfo!=null){
  82. user.setPic(picInfo.getTagFilePath());
  83. }
  85. UploadFileInfofileInfo=myRequest.upload("fileName",
  86. "/WEB-INF/resource");
  87. if(fileInfo!=null){
  88. user.setFilePath(fileInfo.getTagFilePath());
  89. user.setFileName(fileInfo.getSrcFileName());
  90. user.setFileSize(fileInfo.getFileSize());
  91. }
  93. dao.add(user);
  95. //提交完成移除session中设置的随机标示
  96. request.getSession().removeAttribute(randomName);
  97. }else{
  98. request.setAttribute("error","重复提交请求……");
  99. }
  100. list(request,response);
  101. }
  103. publicvoidlist(HttpServletRequestrequest,HttpServletResponseresponse){
  104. List<User>list=dao.list();
  105. request.setAttribute("list",list);
  106. try{
  107. request.getRequestDispatcher("/WEB-INF/jsp/list.jsp").forward(
  108. request,response);
  109. }catch(ServletExceptione){
  110. e.printStackTrace();
  111. }catch(IOExceptione){
  112. e.printStackTrace();
  113. }
  114. }
  116. publicvoidupload(HttpServletRequestrequest,HttpServletResponseresponse){
  117. try{
  118. //防止重复提交
  119. StringrandomName=UUID.randomUUID().toString();
  120. StringrandomValue=UUID.randomUUID().toString();
  122. request.setAttribute("randomName",randomName);
  123. request.setAttribute("randomValue",randomValue);
  124. //当前产生的标示放到session.
  125. request.getSession().setAttribute(randomName,randomValue);
  127. request.getRequestDispatcher("/WEB-INF/jsp/upload.jsp").forward(
  128. request,response);
  130. }catch(ServletExceptione){
  131. e.printStackTrace();
  132. }catch(IOExceptione){
  133. e.printStackTrace();
  134. }
  135. }
  137. @Override
  138. protectedvoiddoMethod(HttpServletRequestrequest,
  139. HttpServletResponseresponse){
  140. list(request,response);
  141. }
  143. publicvoiddownload(HttpServletRequestrequest,
  144. HttpServletResponseresponse){
  145. Stringid=request.getParameter("id");
  146. Useruser=dao.get(Long.parseLong(id));
  148. //发送下载请求给浏览器
  149. response.setContentType("application/x-msdownload");
  150. try{
  151. //解决下载时文件名乱码问题.
  152. response.setHeader("Content-Disposition","attachment;filename="
  153. +URLEncoder.encode(user.getFileName(),"utf-8"));
  154. }catch(UnsupportedEncodingExceptione){
  155. e.printStackTrace();
  156. }
  158. BufferedOutputStreambos=null;
  159. BufferedInputStreambis=null;
  160. try{
  161. bos=newBufferedOutputStream(response.getOutputStream());
  162. bis=newBufferedInputStream(newFileInputStream(newFile(
  163. getServletContext().getRealPath("/"),user.getFilePath())));
  165. byte[]b=newbyte[1024];
  167. intlenth=0;
  168. while((lenth=bis.read(b))!=-1){
  169. bos.write(b,0,lenth);
  170. bos.flush();
  171. }
  172. }catch(IOExceptione){
  173. e.printStackTrace();
  174. }finally{
  175. try{
  176. bos.close();
  177. bis.close();
  178. }catch(IOExceptione){
  179. e.printStackTrace();
  180. }
  181. }
  182. }
  183. }

MyException.java类

[java] view plaincopyprint?

  1. packagecn.itcast.cd.Utils;
  3. publicclassMyExceptionextendsRuntimeException{
  4. publicMyException(Stringmessage){
  5. super(message);
  6. }
  7. }

UploadFileInfo.java类：

[java] view plaincopyprint?

  1. packagecn.itcast.cd.Utils;
  3. publicclassUploadFileInfo{
  4. privateStringsrcFileName;
  5. privateStringtagFilePath;
  6. privatelongfileSize;
  7. publicStringgetSrcFileName(){
  8. returnsrcFileName;
  9. }
  10. publicvoidsetSrcFileName(StringsrcFileName){
  11. this.srcFileName=srcFileName;
  12. }
  13. publicStringgetTagFilePath(){
  14. returntagFilePath;
  15. }
  16. publicvoidsetTagFilePath(StringtagFilePath){
  17. this.tagFilePath=tagFilePath;
  18. }
  19. publiclonggetFileSize(){
  20. returnfileSize;
  21. }
  22. publicvoidsetFileSize(longfileSize){
  23. this.fileSize=fileSize;
  24. }
  25. publicUploadFileInfo(StringsrcFileName,StringtagFilePath,longfileSize){
  26. super();
  27. this.srcFileName=srcFileName;
  28. this.tagFilePath=tagFilePath;
  29. this.fileSize=fileSize;
  30. }
  31. }
Utils.java类：

[java] view plaincopyprint?

  1. packagecn.itcast.cd.Utils;
  3. importjava.util.Properties;
  5. importjavax.sql.DataSource;
  7. importorg.apache.commons.dbcp.BasicDataSourceFactory;
  9. publicclassUtils{
  10. privatestaticDataSourcedataSource;
  12. static{
  13. Propertiesproperties=newProperties();
  14. try{
  15. properties.load(Utils.class.getClassLoader().getResourceAsStream("jdbc.properties"));
  16. dataSource=BasicDataSourceFactory.createDataSource(properties);
  17. }catch(Exceptione){
  18. e.printStackTrace();
  19. }
  20. }
  22. publicstaticDataSourcegetDataSource(){
  23. returndataSource;
  24. }
  25. }



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