Shun 发表于 2021-10-21 16:58:06

JSP servlet实现文件上传下载和删除

本文实例为大家分享了Android九宫格图片展示的具体代码,供大家参考,具体内容如下
由于存储空间,对一般用户而言,就是用来操作存储文件的,所以这两天,特意看了一下windows下用servlet实现文件上传、下载和删除,下面是详细代码说明

上传:

用的是commons-fileupload-1.2.2.jar和commons-io-2.0.1.jar组件,可以去apache官网上去下载,然后放到WebRoot/WEB-INF/lib目录下

upload.html


<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=GBK">
<title>File upload</title>
</head>
<body>
<!-- action="fileupload"对应web.xml中<servlet-mapping>中<url-pattern>的设置.-->
<!-- 必须是multipart的表单数据,才能完整的传递文件数据 -->
<form name="myform" action="fileupload" method="post"
    enctype="multipart/form-data">
    File:<br>
    <input type="file" name="myfile"><br>
    <br>
    <input type="submit" name="submit" value="Commit">
</form>
</body>
</html>
web.xml里加上下面几行:


<servlet>
<servlet-name>Upload</servlet-name>
<servlet-class>am.demo.Upload</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>Upload</servlet-name>
<url-pattern>/fileupload</url-pattern>
</servlet-mapping>
src目录下新建文件Upload.java:


package am.demo;

import java.io.File;
import java.io.IOException;
import java.util.Iterator;
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.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;

@SuppressWarnings("serial")
public class Upload extends HttpServlet {
private String uploadPath = "d://temp"; // 上传文件的目录

@SuppressWarnings("unchecked")
public void doPost(HttpServletRequest request, HttpServletResponse response)
      throws IOException, ServletException {
    try {
      // Create a factory for disk-based file items
      DiskFileItemFactory factory = new DiskFileItemFactory();


      // Create a new file upload handler
      ServletFileUpload upload = new ServletFileUpload(factory);


      List<FileItem> items = upload.parseRequest(request);// 得到所有的文件
      Iterator<FileItem> i = items.iterator();
      while (i.hasNext()) {
      FileItem fi = (FileItem) i.next();
      String fileName = fi.getName();
      if (fileName != null) {
          File fullFile = new File(fi.getName());
          File savedFile = new File(uploadPath, fullFile.getName());
          fi.write(savedFile);
      }
      }
      
      response.setContentType("text/html;charset=GBK");
      response.getWriter().print(
      "<mce:script language='javascript'><!--
alert('上传成功');window.location.href='index.jsp';
// --></mce:script>");
    } catch (Exception e) {
      // 可以跳转出错页面
      e.printStackTrace();
    }
}

public void init() throws ServletException {
    File uploadFile = new File(uploadPath);
    if (!uploadFile.exists()) {
      uploadFile.mkdirs();
    }
}
}
再看下载Downlaod.java:


package am.demo;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.OutputStream;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@SuppressWarnings("serial")
public class Download extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
      throws IOException, ServletException {


    String aFileName = new String(request.getParameter("name").getBytes(
      "iso8859-1"), "gbk");

    File fileLoad = new File("d:/temp", aFileName);

    FileInputStream in = null; // 输入流
    OutputStream out = response.getOutputStream();
    byte b[] = new byte;

    try {

       response.setContentType("application/x-msdownload;");

      response.setHeader("Content-disposition", "attachment; filename="
          + new String(aFileName.getBytes("GBK"), "ISO-8859-1"));

      // download the file.
      in = new FileInputStream(fileLoad);
      int n = 0;
      while ((n = in.read(b)) != -1) {
      out.write(b, 0, n);
      }

    } catch (Throwable e) {
      e.printStackTrace();
    } finally {
      try {
      in.close();
      out.close();
      } catch (Throwable e) {
      e.printStackTrace();
      }
    }
}

public void doPost(HttpServletRequest request, HttpServletResponse response)
      throws IOException, ServletException {
    doGet(request, response);
}

}
删除Delete.java:


package am.demo;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@SuppressWarnings("serial")
public class Delete extends HttpServlet {

public void doGet(HttpServletRequest request, HttpServletResponse response)
      throws FileNotFoundException, IOException {

    String aFileName = new String(request.getParameter("name").getBytes(
      "iso8859-1"), "gbk");

    File file = new File("d:/temp", aFileName);

    response.setContentType("text/html;charset=GBK");

    if (!file.isDirectory()) {
      file.delete();
      response.getWriter().print(
      "<mce:script language='javascript'><!--
alert('删除成功');window.location.href='index.jsp';
// --></mce:script>");
    } else {

    }

}

public void doPost(HttpServletRequest request, HttpServletResponse response)
      throws IOException, ServletException {
    doGet(request, response);
}
}
因为ubuntu server是黑屏,本人用的是ubuntu server10.04,不方便用浏览器来查看文件,因为没有图形界面,也不方便调试,所以可以先在windows上测试通过,然后把相应文件拷到ubuntu server中的tomcat相应目录下,可以通过samba来传文件,但遇到一个问题,就是中文乱码的问题,因为在开始安装时,选的是英文,后面用网上的一些办法,还是没有解决中文乱码的问题,有知道的大侠,还烦请转告。
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持CodeAE代码之家。


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