文件下载

package com.prs.framework.common.util;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.PrintWriter;

import javax.servlet.http.HttpServletResponse;

public class FileDownloadUtil {

	private FileDownloadUtil() {

	}

	/**
	 * 下载文件
	 * @param filePath --文件完整路径
	 * @param response --HttpServletResponse对象
	 */
	public static void downloadFile(String filePath, HttpServletResponse response) {

		String fileName = ""; // 文件名，输出到用户的下载对话框
		// 从文件完整路径中提取文件名，并进行编码转换，防止不能正确显示中文名
		try {
			if (filePath.lastIndexOf("/") > 0) {
				fileName = new String(filePath.substring(filePath.lastIndexOf("/") + 1, filePath.length()).getBytes("GB2312"), "ISO8859_1");
			} else if (filePath.lastIndexOf("\\") > 0) {
				fileName = new String(filePath.substring(filePath.lastIndexOf("\\") + 1, filePath.length()).getBytes("GB2312"), "ISO8859_1");
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
		// 打开指定文件的流信息
		FileInputStream fs = null;
		try {
			fs = new FileInputStream(new File(filePath));
		} catch (FileNotFoundException e) {
			e.printStackTrace();
			return;
		}
		// 设置响应头和保存文件名
		response.setContentType("APPLICATION/OCTET-STREAM");
		response.setHeader("Content-Disposition", "attachment; filename=\"" + fileName + "\"");
		// 写出流信息
		int b = 0;
		try {
			PrintWriter out = response.getWriter();
			while ((b = fs.read()) != -1) {
				out.write(b);
			}
			fs.close();
			out.close();
			System.out.println("文件下载完毕.");
		} catch (Exception e) {
			e.printStackTrace();
			System.out.println("下载文件失败!");
		}
	}

}