initparamservlet.java

介绍了j2ee开发常用的学习知识,如servlet,javamail,EJB等知识,并有项目源码.

/*
 * InitParamServlet.java
 *
 * Created on 2007年10月16日, 上午9:58
 */

package com.servlet;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class InitParamServlet extends HttpServlet {
    ServletConfig myconfig;
    public void init(ServletConfig config) throws ServletException {
            super.init(config);
            
            myconfig=config;
        }
        protected void doGet(HttpServletRequest request,
                HttpServletResponse res) throws ServletException, IOException {
            res.setContentType( "application/pdf" );
            ServletOutputStream out =res.getOutputStream();
            File pdf =null;
            BufferedInputStream buf=null;
            //获取初始化参数
            String pdfDir = myconfig.getInitParameter("FilePath");
            if (pdfDir == null || pdfDir.equals(""))
                throw new ServletException(
                        "Servlet parameters Wrongs");
            try{
                pdf=new File(pdfDir+"sample.pdf");
                res.setContentLength( (int) pdf.length( ) );
                FileInputStream input = new FileInputStream(pdf);
                buf = new BufferedInputStream(input);
                int readBytes = 0;
                //从文件读出数据并写入 ServletOutputStream
                while((readBytes = buf.read( )) != -1)
                    out.write(readBytes);
            } catch(IOException e){
                System.out.println("file not found!");
            }finally {
                //关闭输入输出流
                if (out != null)
                    out.close( );
                if (buf != null)
                    buf.close( );
            }
        }
    }