关于servlet中文件的上传和下载
jar包
jsp页面代码：
<script type="text/javascript">
function addFile(){
//得到div容器
var div1 = document.getElementById("div1");
div1.innerHTML += "<div><input type='file' name='photo' /><input type='button' value='删除' onclick='delFile(this)'/><br /></div>";
}
function delFile(input){
input.parentNode.parentNode.removeChild(input.parentNode);
}
</script>
<body>
<form enctype="multipart/form-data"
action="${pageContext.request.contextPath }/servlet/uploadServlet2"
method="post">
<input type="text" name="name" /><br />
<div id="div1">
<div>
<input type="file" name="photo" /><input type="button" value="添加" onclick="addFile()"/><br />
</div>
</div>
<input type="submit" value="上传" /><br />
</form>
</body>
servlet代码
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.util.List;
import java.util.UUID;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileUploadBase;
import org.apache.commons.fileupload.FileUploadException;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import org.apache.commons.io.FilenameUtils;
public class UploadServlet2 extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
// request.setCharacterEncoding("UTF-8");
// 要执行文件上传的操作
// 判断表单是否支持文件上传。即：enctype="multipart/form-data"
boolean isMultipartContent = ServletFileUpload.isMultipartContent(request);
if (!isMultipartContent) {
throw new RuntimeException("your form is not multipart/form-data");
}
// 创建一个DiskFileItemfactory工厂类
DiskFileItemFactory factory = new DiskFileItemFactory();
factory.setRepository(new File("f:\\"));// 指定临时文件的存储目录
// 创建一个ServletFileUpload核心对象
ServletFileUpload sfu = new ServletFileUpload(factory);
// 解决上传表单项乱码问题
sfu.setHeaderEncoding("UTF-8");
// 限制上传文件的大小
// 解析request对象，并得到一个表单项的集合
try {
// sfu.setFileSizeMax(1024*1024*3);//表示3M大小
// sfu.setSizeMax(1024*1024*6);
List<FileItem> fileItems = sfu.parseRequest(request);
// 遍历表单项数据
for (FileItem fileitem : fileItems) {
if (fileitem.isFormField()) {
// 普通表单项
processFormField(fileitem);
} else {
// 上传表单项
processUploadField(fileitem);
}
}
} catch (FileUploadBase.FileSizeLimitExceededException e) {
// throw new RuntimeException("文件过在，不能超过3M");
System.out.println("文件过在，不能超过3M");
} catch (FileUploadBase.SizeLimitExceededException e) {
System.out.println("总文件大小不能超过6M");
} catch (FileUploadException e) {
e.printStackTrace();
}
}
private void processUploadField(FileItem fileitem) {
try {
// 得到文件输入流
InputStream is = fileitem.getInputStream();
// 创建一个文件存盘的目录
String directoryRealPath = this.getServletContext().getRealPath(
"/WEB-INF/upload");
File storeDirectory = new File(directoryRealPath);// 即代表文件又代表目录
if (!storeDirectory.exists()) {
storeDirectory.mkdirs();// 创建一个指定的目录
}
// 得到上传的名子
String filename = fileitem.getName();// 文件项中的值 F:\图片素材\小清新\43.jpg 或者
// 43.jpg
if (filename != null) {
// filename =
// filename.substring(filename.lastIndexOf(File.separator)+1);
filename = FilenameUtils.getName(filename);// 效果同上
}
// 解决文件同名的问题
filename = UUID.randomUUID() + "_" + filename;
// 目录打散
// String childDirectory = makeChildDirectory(storeDirectory); //
// 2015-10-19
String childDirectory = makeChildDirectory(storeDirectory, filename); // a/b
// 上传文件，自动删除临时文件
fileitem.write(new File(storeDirectory, childDirectory
+ File.separator + filename));
fileitem.delete();
} catch (IOException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
}
// 上传表单项
private void processUploadField1(FileItem fileitem) {
try {
// 得到文件输入流
InputStream is = fileitem.getInputStream();
// 创建一个文件存盘的目录
String directoryRealPath = this.getServletContext().getRealPath(
"/WEB-INF/upload");
File storeDirectory = new File(directoryRealPath);// 即代表文件又代表目录
if (!storeDirectory.exists()) {
storeDirectory.mkdirs();// 创建一个指定的目录
}
// 得到上传的名子
String filename = fileitem.getName();// 文件项中的值 F:\图片素材\小清新\43.jpg 或者
// 43.jpg
// 处理文件名
/*
* 解决此问题： F:\\apache-tomcat-7.0.52\\webapps\\day18_00_upload\\upload\\F:\\图片素材\\小清新\\41.jpg
*/
if (filename != null) {
// filename =
// filename.substring(filename.lastIndexOf(File.separator)+1);
filename = FilenameUtils.getName(filename);// 效果同上
}
// 解决文件同名的问题
filename = UUID.randomUUID() + "_" + filename;
// 目录打散
// String childDirectory = makeChildDirectory(storeDirectory); //
// 2015-10-19
String childDirectory = makeChildDirectory(storeDirectory, filename); // 2015-10-19
// 在storeDirectory下，创建完整目录下的文件
File file = new File(storeDirectory, childDirectory
+ File.separator + filename); // 绝对目录/日期目录/文件名
// 通过文件输出流将上传的文件保存到磁盘
FileOutputStream fos = new FileOutputStream(file);
int len = 0;
byte[] b = new byte[1024];
while ((len = is.read(b)) != -1) {
fos.write(b, 0, len);
}
fos.close();
is.close();
fileitem.delete();
} catch (IOException e) {
e.printStackTrace();
}
}
// 目录打散
private String makeChildDirectory(File storeDirectory, String filename) {
int hashcode = filename.hashCode();// 返回字符转换的32位hashcode码
System.out.println(hashcode);
String code = Integer.toHexString(hashcode); // 把hashcode转换为16进制的字符
// abdsaf2131safsd
System.out.println(code);
String childDirectory = code.charAt(0) + File.separator
+ code.charAt(1); // a/b
// 创建指定目录
File file = new File(storeDirectory, childDirectory);
if (!file.exists()) {
file.mkdirs();
}
return childDirectory;
}
// 按日期打散
/*
* private String makeChildDirectory(File storeDirectory) {
*
* SimpleDateFormat sdf =new SimpleDateFormat("yyyy-MM-dd"); String
* dateDirectory = sdf.format(new Date()); //只管创建目录 File file = new
* File(storeDirectory,dateDirectory); if(!file.exists()){ file.mkdirs(); }
*
* return dateDirectory; }
*/
// 普通表单项
private void processFormField(FileItem fileitem) {
try {
String fieldname = fileitem.getFieldName();// 字段名
String fieldvalue = fileitem.getString("UTF-8");// 字段值
//fieldvalue = new String(fieldvalue.getBytes("iso-8859-1"),"utf-8");
System.out.println(fieldname + "=" + fieldvalue);
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}