Jsp&Servlet实现读取本地图片并展示

浏览数：34 / 时间：2015年06月09日

在Web开发中图片的读取和展示是一个很常见的功能，实现的过程大致也都一样（包括在各种框架中……）！接下来用流的方式来实现图片的展示

1、创建Servlet，实现读取，请求方式使用get请求；

package com.senvn.servlet;

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;

public class ShowImageServlet extends HttpServlet {

    private static final String JPG="image/jpeg;charset=GB2312";
    
    /**
     * get方法
     */
    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        // 本地文件路径
        String filePath = "D:"+File.separator+"temp"+File.separator+"test1.jpg";
        File file = new File(filePath);
        // 获取输出流
        OutputStream outputStream = response.getOutputStream();
        FileInputStream fileInputStream = new FileInputStream(file);
        // 读数据
        byte[] data = new byte[fileInputStream.available()];
        fileInputStream.read(data);
        fileInputStream.close();
        // 回写
        response.setContentType(JPG);
        outputStream.write(data);
        outputStream.flush();
        outputStream.close();
    }
    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        
    }
}

2、配置文件，web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
  <display-name>Servlet</display-name>
  <servlet>
    <description>显示图片Servlet</description>
    <display-name>显示图片</display-name>
    <servlet-name>ShowImageServlet</servlet-name>
    <servlet-class>com.senvn.servlet.ShowImageServlet</servlet-class>
  </servlet>

  <servlet-mapping>
    <servlet-name>ShowImageServlet</servlet-name>
    <url-pattern>/showImage.do</url-pattern>
  </servlet-mapping>
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
</web-app>

3、页面展示

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">
    <title>My JSP ‘upload.jsp‘ starting page</title>
  </head>
  
  <body>
   <img alt="showImage" src="/Servlet/showImage.do">
  </body>
</html>