前提条件

• Tomcat 7.0.90

方法一：修改配置文件

在TOMCAT_HOME/conf/server.xml配置文件内的<Host>内添加一子标签：

<Context docBase="C:\exambase\" path="/img"/>

方法二：添加Servlet

新建一应用，然后添加如下的Servlet，然后部署应用启动Tomcat。

package com.lun.servlet;import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;@WebServlet(name = "imgservlet", urlPatterns = { "/imgservlet/*" })
public class ImgServlet extends HttpServlet {private static final long serialVersionUID = -3351976768417931566L;private static final String IMG_PATH = "C:/exambase";protected void doGet(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {doPost(request, response);}protected void doPost(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {String pathInfo = request.getPathInfo();try{BufferedInputStream in = new BufferedInputStream(new FileInputStream(String.format("%s%s", IMG_PATH, pathInfo)));BufferedOutputStream out = new BufferedOutputStream(response.getOutputStream());try {byte[] content = new byte[in.available()];in.read(content);response.setContentType("image/png,image/jpeg,image/gif,image/bmp");out.write(content);}finally {in.close();out.close();}}catch(FileNotFoundException ex) {throw new IOException(String.format("%s Not Found.", pathInfo));}catch(Exception ex) {throw ex;			}}
}

解决路径含中文时出现乱码问题

本次测试使用的是Tomcat/7.0.90，默认解码URL的字符集是ISO-8859-1，而浏览器发出URL是用UTF-8编码。若URL含中文，乱码现象自然而然会发生。

解决之道：在TOMCAT_HOME/conf/server.xml配置文件内的

<Connector connectionTimeout="20000" port="8080"protocol="HTTP/1.1" redirectPort="8443" />

添加一属性URIEncoding="UTF-8"。

参考资料

1. tomcat做图片服务器
2. 使用Servlet显示图片
3. Java Servlet @WebServlet Annotation Example
4. Servlet and path parameters like /xyz/{value}/test, how to map in web.xml?
5. 关于使用Tomcat搭建的Web项目，出现 URL 中文乱码的问题解析