/**
* Copyright (c) 2011-2017, James Zhan 詹波 (jfinal@126.com).
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.jfinal.render;
import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.jfinal.kit.LogKit;
import com.jfinal.kit.StrKit;
/**
* FileRender.
*/
public class FileRender extends Render {
private static final String DEFAULT_CONTENT_TYPE = "application/octet-stream";
private File file;
private static String baseDownloadPath;
private static ServletContext servletContext;
private String downloadFileName = null;
public FileRender(File file) {
if (file == null) {
throw new IllegalArgumentException("file can not be null.");
}
this.file = file;
}
public FileRender(File file, String downloadFileName) {
this(file);
if (StrKit.isBlank(downloadFileName)) {
throw new IllegalArgumentException("downloadFileName can not be blank.");
}
this.downloadFileName = downloadFileName;
}
public FileRender(String fileName) {
if (StrKit.isBlank(fileName)) {
throw new IllegalArgumentException("fileName can not be blank.");
}
String fullFileName;
fileName = fileName.trim();
if (fileName.startsWith("/") || fileName.startsWith("\\")) {
if (baseDownloadPath.equals("/")) {
fullFileName = fileName;
} else {
fullFileName = baseDownloadPath + fileName;
}
} else {
fullFileName = baseDownloadPath + File.separator + fileName;
}
this.file = new File(fullFileName);
}
public FileRender(String fileName, String downloadFileName) {
this(fileName);
if (StrKit.isBlank(downloadFileName)) {
throw new IllegalArgumentException("downloadFileName can not be blank.");
}
this.downloadFileName = downloadFileName;
}
static void init(String baseDownloadPath, ServletContext servletContext) {
FileRender.baseDownloadPath = baseDownloadPath;
FileRender.servletContext = servletContext;
}
public void render() {
if (file == null || !file.isFile()) {
RenderManager.me().getRenderFactory().getErrorRender(404).setContext(request, response).render();
return ;
}
// ---------
response.setHeader("Accept-Ranges", "bytes");
String fn = downloadFileName == null ? file.getName() : downloadFileName;
response.setHeader("Content-disposition", "attachment; " + encodeFileName(request, fn));
String contentType = servletContext.getMimeType(file.getName());
response.setContentType(contentType != null ? contentType : DEFAULT_CONTENT_TYPE);
// ---------
if (StrKit.isBlank(request.getHeader("Range"))) {
normalRender();
} else {
rangeRender();
}
}
protected String encodeFileName(String fileName) {
try {
// return new String(fileName.getBytes("GBK"), "ISO8859-1");
return new String(fileName.getBytes(getEncoding()), "ISO8859-1");
} catch (UnsupportedEncodingException e) {
return fileName;
}
}
/**
* 依据浏览器判断编码规则
*/
public String encodeFileName(HttpServletRequest request, String fileName) {
String userAgent = request.getHeader("User-Agent");
try {
String encodedFileName = URLEncoder.encode(fileName, "UTF8");
// 如果没有UA，则默认使用IE的方式进行编码
if (userAgent == null) {
return "filename=\"" + encodedFileName + "\"";
}
userAgent = userAgent.toLowerCase();
// IE浏览器，只能采用URLEncoder编码
if (userAgent.indexOf("msie") != -1) {
return "filename=\"" + encodedFileName + "\"";
}
// Opera浏览器只能采用filename*
if (userAgent.indexOf("opera") != -1) {
return "filename*=UTF-8''" + encodedFileName;
}
// Safari浏览器，只能采用ISO编码的中文输出,Chrome浏览器，只能采用MimeUtility编码或ISO编码的中文输出
if (userAgent.indexOf("safari") != -1 || userAgent.indexOf("applewebkit") != -1 || userAgent.indexOf("chrome") != -1) {
return "filename=\"" + new String(fileName.getBytes("UTF-8"), "ISO8859-1") + "\"";
}
// FireFox浏览器，可以使用MimeUtility或filename*或ISO编码的中文输出
if (userAgent.indexOf("mozilla") != -1) {
return "filename*=UTF-8''" + encodedFileName;
}
return "filename=\"" + encodedFileName + "\"";
} catch (UnsupportedEncodingException e) {
throw new RuntimeException(e);
}
}
private void normalRender() {
response.setHeader("Content-Length", String.valueOf(file.length()));
InputStream inputStream = null;
OutputStream outputStream = null;
try {
inputStream = new BufferedInputStream(new FileInputStream(file));
outputStream = response.getOutputStream();
byte[] buffer = new byte[1024];
for (int len = -1; (len = inputStream.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);}
}
}
private void rangeRender() {
Long[] range = {null, null};
processRange(range);
String contentLength = String.valueOf(range[1].longValue() - range[0].longValue() + 1);
response.setHeader("Content-Length", contentLength);
response.setStatus(HttpServletResponse.SC_PARTIAL_CONTENT); // status = 206
// Content-Range: bytes 0-499/10000
StringBuilder contentRange = new StringBuilder("bytes ").append(String.valueOf(range[0])).append("-").append(String.valueOf(range[1])).append("/").append(String.valueOf(file.length()));
response.setHeader("Content-Range", contentRange.toString());
InputStream inputStream = null;
OutputStream outputStream = null;
try {
long start = range[0];
long end = range[1];
inputStream = new BufferedInputStream(new FileInputStream(file));
if (inputStream.skip(start) != start)
throw new RuntimeException("File skip error");
outputStream = response.getOutputStream();
byte[] buffer = new byte[1024];
long position = start;
for (int len; position <= end && (len = inputStream.read(buffer)) != -1;) {
if (position + len <= end) {
outputStream.write(buffer, 0, len);
position += len;
}
else {
for (int i=0; i<len && position <= end; i++) {
outputStream.write(buffer[i]);
position++;
}
}
}
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);}
}
}
/**
* Examples of byte-ranges-specifier values (assuming an entity-body of length 10000):
* The first 500 bytes (byte offsets 0-499, inclusive): bytes=0-499
* The second 500 bytes (byte offsets 500-999, inclusive): bytes=500-999
* The final 500 bytes (byte offsets 9500-9999, inclusive): bytes=-500
* Or bytes=9500-
*/
private void processRange(Long[] range) {
String rangeStr = request.getHeader("Range");
int index = rangeStr.indexOf(',');
if (index != -1)
rangeStr = rangeStr.substring(0, index);
rangeStr = rangeStr.replace("bytes=", "");
String[] arr = rangeStr.split("-", 2);
if (arr.length < 2)
throw new RuntimeException("Range error");
long fileLength = file.length();
for (int i=0; i<range.length; i++) {
if (StrKit.notBlank(arr[i])) {
range[i] = Long.parseLong(arr[i].trim());
if (range[i] >= fileLength)
range[i] = fileLength - 1;
}
}
// Range format like: 9500-
if (range[0] != null && range[1] == null) {
range[1] = fileLength - 1;
}
// Range format like: -500
else if (range[0] == null && range[1] != null) {
range[0] = fileLength - range[1];
range[1] = fileLength - 1;
}
// check final range
if (range[0] == null || range[1] == null || range[0].longValue() > range[1].longValue())
throw new RuntimeException("Range error");
}
}