文件 , 图片,导入项目问题解决

package demo;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

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

/**

• Servlet implementation class Download
  */
  @WebServlet("/download.do")
  public class Down![在这里插入图片描述](https://img-blog.csdnimg.cn/20191017165519453.gifload extends HttpServlet {
  private static final long serialVersionUID = 1L;

  /**

  • @see HttpServlet#HttpServlet()
    */
    public Download() {
    super();
    // TODO Auto-generated constructor stub
    }

  /**

  • @see HttpServlet#service(HttpServletRequest request, HttpServletResponse response)
    */
    protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    response.setContentType(“application/pdf”);
    InputStream in = getServletContext().getResourceAsStream("/WEB-INF/java.pdf");
    OutputStream out = response.getOutputStream();
    writeBytes(in,out);

  }

  private void writeBytes(InputStream in, OutputStream out) throws IOException {
  byte[] buffer = new byte[1024];
  int length = -1;
  while((length=in.read(buffer))!=-1) {
  out.write(buffer,0,length);
  }
  in.close();
  out.close();
  }

}

package demo;

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

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

/**

• Servlet implementation class Download
  */
  @WebServlet("/downloadImage.do")
  public class DownloadImage extends HttpServlet {
  private static final long serialVersionUID = 1L;

  /**

  • @see HttpServlet#HttpServlet()
    */
    public DownloadImage() {
    super();
    // TODO Auto-generated constructor stub
    }

  /**

  • @see HttpServlet#service(HttpServletRequest request, HttpServletResponse response)
    */
    protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    response.setContentType(“image/png”);
    //InputStream in = getServletContext().getResourceAsStream("/WEB-INF/2019-04-25_103931.png");
    File file =new File(“C:\Users\tanna\Pictures\multiple-tomcat-serivces-1.png”);
    System.out.println(file.getName());
    InputStream in = new FileInputStream(file);
    OutputStream out = response.getOutputStream();
    writeBytes(in,out);

  }

  private void writeBytes(InputStream in, OutputStream out) throws IOException {
  byte[] buffer = new byte[1024];
  int length = -1;
  while((length=in.read(buffer))!=-1) {
  out.write(buffer,0,length);
  }
  in.close();
  out.close();
  }

}