From 1e79cefe833791e7ffcd81cd1beb4021319ad86f Mon Sep 17 00:00:00 2001
From: p10297854 <944423246@qq.com>
Date: Fri, 9 Jul 2021 18:14:58 +0800
Subject: [PATCH] ADD file via upload

---
 back/src/com/demo/files/ReadFileServlet.java | 120 +++++++++++++++++++
 1 file changed, 120 insertions(+)
 create mode 100644 back/src/com/demo/files/ReadFileServlet.java

diff --git a/back/src/com/demo/files/ReadFileServlet.java b/back/src/com/demo/files/ReadFileServlet.java
new file mode 100644
index 0000000..64b8062
--- /dev/null
+++ b/back/src/com/demo/files/ReadFileServlet.java
@@ -0,0 +1,120 @@
+package com.demo.files;
+
+import java.io.DataOutputStream;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.io.PrintWriter;
+import java.net.URLEncoder;
+import java.sql.Blob;
+import java.sql.Connection;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.sql.Statement;
+import java.util.ArrayList;
+import java.util.List;
+
+import javax.servlet.RequestDispatcher;
+import javax.servlet.ServletException;
+import javax.servlet.ServletOutputStream;
+import javax.servlet.annotation.WebServlet;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import javax.sql.rowset.serial.SerialBlob;
+
+import org.apache.commons.fileupload.FileItem;
+import org.apache.commons.fileupload.FileUploadException;
+import org.apache.commons.io.IOUtils;
+
+import com.domain.GetDBConnection;
+import com.domain.Types;
+
+import net.sf.json.JSONObject;
+import net.sourceforge.tess4j.Tesseract;
+import net.sourceforge.tess4j.TesseractException;
+
+/**
+ * Servlet implementation class ReadFileServlet
+ */
+@WebServlet("/readfil-servlet")
+public class ReadFileServlet extends HttpServlet {
+	private static final long serialVersionUID = 1L;
+       
+    /**
+     * @see HttpServlet#HttpServlet()
+     */
+    public ReadFileServlet() {
+        super();
+        // TODO Auto-generated constructor stub
+    }
+
+	/**
+	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
+	 */
+	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
+		// TODO Auto-generated method stub
+		 Connection con=null;
+	      Statement sql; 
+	      ResultSet rs;
+	      PreparedStatement preSql;
+		con = GetDBConnection.connectDB("musicMySQL","root","root");
+	     if(con == null ) return;
+	     try {
+			 sql=con.createStatement();
+			 con.setAutoCommit(false);//程序必须调用commit或者rollback方法
+			 String sqlStr ="SELECT * FROM music WHERE filename=?";
+			 preSql = con.prepareStatement(sqlStr);	  
+			 String filename = request.getParameter("filename");
+			 filename = new String(filename.getBytes("iso8859-1"),"UTF-8");
+			 System.out.println(filename);
+			 preSql.setString(1, filename);
+			 rs=preSql.executeQuery();
+			 while(rs.next()) {
+				// String filename=rs.getString("filename");
+				
+				 String filepath = request.getSession().getServletContext().getRealPath("/WEB-INF/upload/"+filename);
+				 Blob blob=rs.getBlob("musicMIDI");
+						
+					InputStream in=blob.getBinaryStream();
+					File file = new File(filepath);
+			        
+			        
+					OutputStream out=new FileOutputStream(file);
+					FileInputStream is = new FileInputStream(file);
+					IOUtils.copy(in, out);
+					//设置相应类型让浏览器知道用什么打开  用application/octet-stream也可以，看是什么浏览器
+					response.setContentType("application/x-msdownload");
+					//设置头信息
+					response.setHeader("Content-Disposition", "attachment;filename=\"" + filename + "\"");
+					//InputStream inputStream = new FileInputStream(file);
+					OutputStream ouputStream = response.getOutputStream();
+					//ouputStream.write(filename.getBytes());
+					byte b[] = new byte[1024];
+					int n =0;
+					while((n = is.read(b)) != -1){
+						ouputStream.write(b,0,n);
+					}
+					IOUtils.copy(in, ouputStream);
+					//关闭流
+					ouputStream.close();
+					in.close();
+			 }
+			//RequestDispatcher view = request.getRequestDispatcher("/index.jsp");
+			//view.forward(request, response);
+		}catch(SQLException e) {
+			//RequestDispatcher view = request.getRequestDispatcher("/index.jsp");
+			//view.forward(request, response);
+		
+		} catch (Exception e) {
+			// TODO Auto-generated catch block
+			e.printStackTrace();
+		}
+	}
+
+}