示例：Servlet读取文件内容并在页面打印输出

package com.mhb;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.io.PrintWriter;

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

public class FileRead extends HttpServlet {

public void init() throws ServletException {
}

public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html");     //设置响应内容格式
response.setCharacterEncoding("gb2312");    //设置响应内容编码
PrintWriter out = response.getWriter();     //获得out对象
String fileName = "content.txt";     //指定文件名称
String realPath = request.getRealPath(fileName);

File file = new File(realPath);

if(file.exists()){
FileReader reader = new FileReader(file);    //获得输入流
BufferedReader bufferReader = new BufferedReader(reader); //使用缓冲流
String line = null;     //每行数据
while ((line = bufferReader.readLine()) != null){    //循环读取
out.print(line +"<br />");     //输出文件内容
}
}else{
out.print("文件不存在！");
}

}

public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
}

public void destroy() {
super.destroy();
}
}

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