一 、处理带说明信息的图片与处理文件上传
void
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delete() 删除保存在临时目录中的文件。 |
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String |
getContentType() 获取文档的类型 Returns the content type passed by the browser or null if not defined. |
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String |
getFieldName() 获取字段的名称，即name=xxxx Returns the name of the field in the multipart form corresponding to this file item. <input type=”file” name=”img”/> |
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InputStream |
getInputStream() Returns an InputStream that can be used to retrieve the contents of the file. |
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String |
getName() Returns the original filename in the client‘s filesystem, as provided by the browser (or other client software). 获取文件名称。 如果是在IＥ获取的文件为 c：\aaa\aaa\xxx.jpg –即完整的路径。 非IE;文件名称只是 xxx.jpg |
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long |
getSize() 获取文件大小 相当于in.avilivable(); Returns the size of the file item |
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如果你上传是一普通的文本元素，则可以通过以下方式获取元素中的数据 <form enctype=”multipart/form-data”> <input |
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String |
getString() 用于获取普通的表单域的信息。 Returns the contents of the file item as a String, using the default character encoding.（IOS-8859-1） |
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String |
getString(String encoding) 可以指定编码格式 Returns the contents of the file item as a String, using the specified encoding. |
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void |
write(File file) 直接将文件保存到另一个文件中去。 A convenience method to write an uploaded item to disk. |
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以下文件用判断一个fileItem是否是file（type=file）对象或是text(type=text|checkbox|radio)对象： |
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boolean
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isFormField() 如果是text|checkbox|radio|select这个值就是true.Determines whether or not a FileItem instance represents a simple form field.
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代码：
public class UpDescServlet extends HttpServlet {
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
request.setCharacterEncoding("UTF-8");//可以获取中文的文件名
String path = getServletContext().getRealPath("/up");
DiskFileItemFactory disk =
new DiskFileItemFactory();
disk.setRepository(new File("d:/a"));
try{
ServletFileUpload up =
new ServletFileUpload(disk);
List<FileItem> list = up.parseRequest(request);
for(FileItem file:list){
//第一步：判断是否是普通的表单项
if(file.isFormField()){
String fileName = file.getFieldName();//<input type="text" name="desc">=desc
String value = file.getString("UTF-8");//默认以ISO方式读取数据
System.err.println(fileName+"="+value);
}else{//说明是一个文件
String fileName = file.getName();
fileName = fileName.substring(fileName.lastIndexOf("\\")+1);
file.write(new File(path+"/"+fileName));
System.err.println("文件名是:"+fileName);
System.err.println("文件大小是："+file.getSize());
file.delete();
}
}
}catch(Exception e){
e.printStackTrace();
}
}
}
二 处理文件上传（性能能够相对之前提升）
核心点用FileItemIterator it= up.getItemIterator(request);处理文件上传。
package cn.hx.servlet;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.List;
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.FileItemIterator;
import org.apache.commons.fileupload.FileItemStream;
import org.apache.commons.fileupload.RequestContext;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import org.apache.commons.fileupload.servlet.ServletRequestContext;
import org.apache.commons.io.FileUtils;
public class FastServlet extends HttpServlet {
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
request.setCharacterEncoding("UTF-8");
String path = getServletContext().getRealPath("/up");
DiskFileItemFactory disk =
new DiskFileItemFactory();
disk.setRepository(new File("d:/a"));
try{
ServletFileUpload up = new ServletFileUpload(disk);
//以下是迭代器模式
FileItemIterator it= up.getItemIterator(request);
while(it.hasNext()){
FileItemStream item = it.next();
String fileName = item.getName();
fileName=fileName.substring(fileName.lastIndexOf("\\")+1);
InputStream in = item.openStream();
FileUtils.copyInputStreamToFile(in,new File(path+"/"+fileName));
}
}catch(Exception e){
e.printStackTrace();
}
}
}