重写jfinal中的render方法 为了实现字符串直接转换为文件给浏览器下载

package com.youka.tools;

import java.io.BufferedInputStream;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import com.jfinal.kit.LogKit;
import com.jfinal.render.Render;
import com.jfinal.render.RenderException;

/**
 * 重写jfinal中的render方法 为了实现字符串直接转换为文件给浏览器下载
 * 
 * @author symbol
 *
 */
public class BinaryRender extends Render {

	private InputStream in;
	private String fileName;

	public BinaryRender(byte[] bytes, String fileName) {
		in = new ByteArrayInputStream(bytes);
		this.fileName = fileName;
	}

	public BinaryRender(InputStream in, String fileName) {
		this.in = in;
		this.fileName = fileName;
	}

	@Override
	public void render() {
		OutputStream outputStream = null;
		InputStream inputStream = null;
		try {
			response.setHeader("Content-disposition",
					"attachment; filename=" + new String(fileName.getBytes(getEncoding()), "ISO8859-1"));
			String contentType = request.getSession().getServletContext().getMimeType(fileName);
			response.setContentType(contentType != null ? contentType : "application/octet-stream");
			inputStream = new BufferedInputStream(in);
			outputStream = response.getOutputStream();
			byte[] buffer = new byte[1024];
			for (int len = -1; (len = in.read(buffer)) != -1;) {
				outputStream.write(buffer, 0, len);
			}
			outputStream.flush();
		} catch (IOException e) {
			if (getDevMode()) {
				throw new RenderException(e);
			}
		} catch (Exception e) {
			throw new RenderException(e);
		} finally {
			if (inputStream != null)
				try {
					inputStream.close();
				} catch (IOException e) {
					LogKit.error(e.getMessage(), e);
				}
			if (outputStream != null)
				try {
					outputStream.close();
				} catch (IOException e) {
					LogKit.error(e.getMessage(), e);
				}
		}
	}
}