javaweb---上傳文件

相關jar包：commons-fileUpload

    commons-io

上傳三步

1:   DiskFileItemFactory factory=new DiskFileItemFactory();

2:   ServletFileUpload  sfu=new ServletFileUpload(factory);

3:   List<FileItem>list=sfu.parseRequest(request);

FileItem:

boolean isFormFiled();//是否爲普通表單項

boolean getFiledName();//獲得表單項的名字

boolean getString(String charset);//獲得表單項的值

String getName();//返回上傳的文件名稱

long getSize();//返回文件的上傳數

InputStream getInputStream();//返回上傳文件的輸入流

void write(File destination);//把上傳文件的內容寫入指定的文件之中

  

 <form action="/weixiong/UploadServlet" method="post" enctype="multipart/form-data"> 
    用戶名:<input type="text" name="usrname"/><br/>
    照    片:<input type="file" name="photo"/><br/>
    <input type="submit" value="上傳"/>
    </form>

package mypack;
import java.io.File;
import java.io.IOException;
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.FileUploadException;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
public class UploadServlet extends HttpServlet {
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
request.setCharacterEncoding("utf-8");
DiskFileItemFactory factory=new DiskFileItemFactory();
ServletFileUpload sfu=new ServletFileUpload(factory);

sfu.setFileSizeMax(1024*100);//限制單個文件上傳爲100K

sfu.setSizeMax(1024*100);限制總共的文件爲100k

try {
List<FileItem>list=sfu.parseRequest(request);
FileItem file1=list.get(0);//普通表單項
FileItem file2=list.get(1);//文件表單項

System.out.println("普通表單項演示");
System.out.println("是不是普通表單項："+file1.isFormField());
System.out.println("表單項的名字是："+file1.getFieldName());
System.out.println("表單項的內容是:"+file1.getString());


System.out.println("文件表單項演示");

String path=getServletContext().getRealPath("/WEB-INF/file");

System.out.println("是不是普通表單項:"+file2.isFormField());
System.out.println("文件表單項的名字是"+file2.getFieldName());
System.out.println("文件的名字是"+file2.getName());
System.out.println("文件表單項的大小:"+file2.getSize());
System.out.println("寫入文件中");
file2.write(new File(path+"\test.doc"));
} catch (FileUploadException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}


}