import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.OutputStream;
import javax.servlet.http.HttpServletResponse;

public class FileDownloadUtil {

    public static void downloadFile(String filePath, String fileName, HttpServletResponse response) throws IOException {
        // 設(shè)置響應(yīng)的Header參數(shù)
        response.reset();
        response.setContentType("application/octet-stream");
        response.setHeader("Content-Disposition", "attachment;filename=" + fileName);

        // 讀取文件內(nèi)容并將其轉(zhuǎn)換為字節(jié)數(shù)組
        FileInputStream fis = new FileInputStream(filePath);
        BufferedInputStream bis = new BufferedInputStream(fis);
        byte[] buffer = new byte[bis.available()];
        bis.read(buffer);

        // 設(shè)置文件的MIME類型
        response.setContentType("application/octet-stream");

        // 設(shè)置響應(yīng)的Content-Disposition頭部信息
        response.setHeader("Content-Disposition", "attachment;filename=" + fileName);

        // 將字節(jié)數(shù)組寫入響應(yīng)的輸出流
        OutputStream os = response.getOutputStream();
        BufferedOutputStream bos = new BufferedOutputStream(os);
        bos.write(buffer);
        bos.flush();

        // 關(guān)閉輸出流
        bos.close();
        bis.close();
    }
}