jsp+servlet简单实现上传文件功能(保存目录改进)(jspservlet增删改查)原创

随心笔谈1年前 (2023)发布 admin
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package Servlet.bookServlet;

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;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.List;

@WebServlet(name=”UploadImageServlet”)
public class UploadImageServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doPost(request,response);
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//1、判断请求是不是multipart请求
if(!ServletFileUpload.isMultipartContent(request)){
throw new RuntimeException(“当前请求不支持文件上传”);
}
System.out.println(“开始上传文件”);
//2、创建FileItem工厂==>文件写入硬盘的作用
try {
DiskFileItemFactory factory=new DiskFileItemFactory();
//3、创建temp临时文件夹
String tempPath=”D:\\tomcat\\apache-tomcat-9.0.35-windows-x64\\apache-tomcat-9.0.35\\webapps\\librarySystem\\web\\net\\temp”;
File tempFile=new File(tempPath);
factory.setRepository(tempFile);
//4、设置使用临时文件的边界值,大于该值,上传文件先保存在临时文件中,小于该值,则直接写入内存
//单位是字节
factory.setSizeThreshold(1024*1024*1);

//5、创建文件上传核心组件
// 调用ServletFileUpload.parseRequest方法解析request对象,得到一个保存了所有上传内容的List对象。
ServletFileUpload upload=new ServletFileUpload(factory);
upload.setHeaderEncoding(“utf-8″);//可以解决文件名中文乱码
upload.setFileSizeMax(1024*1024*2);

String bNo=”defaultBNo”,bName=”defaultBName”;
//6、解析请求
List<FileItem> items=upload.parseRequest(request);
//7、遍历请求
for(FileItem item:items){
//普通表单项,上传名字,编号等普通信息的上i传
if(item.isFormField()){
String fileName=item.getFieldName();// name属性值
String fileValue=item.getString(“utf-8″);// name对应的value值
System.out.println(fileName + ” — ” + fileValue);
if(fileName.equalsIgnoreCase(“BNO”)){
bNo=fileValue;
}
if(fileName.equalsIgnoreCase(“BNAME”)){
bName=fileValue;
}
}
else{//上传图片等
String fileName=item.getName();
System.out.println(“上传文件名字:”+fileName);
String suffix=fileName.substring(fileName.lastIndexOf(‘.’));//获取文件类型
String newFileName=bNo+”_”+bName+suffix;
System.out.println(newFileName);
//获取输入流,其中有上传文件的内容
InputStream is=item.getInputStream();
//String path=this.getServletContext().getRealPath(“/net/bookImage”);//获得当前项目保存服务器地址,也就是web文件夹下
String path=”D:\\tomcat\\apache-tomcat-9.0.35-windows-x64\\apache-tomcat-9.0.35\\webapps\\librarySystem\\web\\net\\bookImage”;
//文件夹内文件数目有上限,但是可以创建子目录
//获取当前系统时间
Calendar now=Calendar.getInstance();
int year=now.get(Calendar.YEAR);
int month=now.get(Calendar.MONTH)+1;
int day=now.get(Calendar.DAY_OF_MONTH);
path=path+”/”+year+”/”+month+”/”+day;
//若该目录不存在,直接创建新目录
File dirFile=new File(path);
if(!dirFile.exists()){
dirFile.mkdirs();
}
//创建目标文件,用来保存上传文件
File desFile=new File(path,newFileName);
//创建文件输出流
OutputStream os=new FileOutputStream(desFile);
//将输入流数据写入到输出流中
int len=-1;
byte[]buf=new byte[1024];
while((len=is.read(buf))!=-1){
os.write(buf,0,len);
}
//desFile.delete();//删除临时文件
os.close();//输出流
is.close();//输入流
//删除临时文件
item.delete();
}
}
} catch (FileUploadException e) {
e.printStackTrace();
}
}
}

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