Java tutorial
/* * Copyright (c) 2013. wyouflf (wyouflf@gmail.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.drive.student.xutils.http.callback; import android.text.TextUtils; import com.drive.student.xutils.util.IOUtils; import org.apache.http.HttpEntity; import java.io.BufferedInputStream; import java.io.BufferedOutputStream; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; public class FileDownloadHandler { public File handleEntity(HttpEntity entity, com.drive.student.xutils.http.callback.RequestCallBackHandler callBackHandler, String target, boolean isResume, String responseFileName) throws IOException { if (entity == null || TextUtils.isEmpty(target)) { return null; } File targetFile = new File(target); if (!targetFile.exists()) { File dir = targetFile.getParentFile(); if (dir.exists() || dir.mkdirs()) { targetFile.createNewFile(); } } long current = 0; BufferedInputStream bis = null; BufferedOutputStream bos = null; try { FileOutputStream fileOutputStream = null; if (isResume) { current = targetFile.length(); fileOutputStream = new FileOutputStream(target, true); } else { fileOutputStream = new FileOutputStream(target); } long total = entity.getContentLength() + current; bis = new BufferedInputStream(entity.getContent()); bos = new BufferedOutputStream(fileOutputStream); if (callBackHandler != null && !callBackHandler.updateProgress(total, current, true)) { return targetFile; } byte[] tmp = new byte[4096]; int len; while ((len = bis.read(tmp)) != -1) { bos.write(tmp, 0, len); current += len; if (callBackHandler != null) { if (!callBackHandler.updateProgress(total, current, false)) { return targetFile; } } } bos.flush(); if (callBackHandler != null) { callBackHandler.updateProgress(total, current, true); } } finally { IOUtils.closeQuietly(bis); IOUtils.closeQuietly(bos); } if (targetFile.exists() && !TextUtils.isEmpty(responseFileName)) { File newFile = new File(targetFile.getParent(), responseFileName); while (newFile.exists()) { newFile = new File(targetFile.getParent(), System.currentTimeMillis() + responseFileName); } return targetFile.renameTo(newFile) ? newFile : targetFile; } else { return targetFile; } } }