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Welcome to the okdownload wiki!

Import okdownload through gradle

// core
com.liulishuo.okdownload:okdownload:{latest_version}
// provide sqlite to store breakpoints
com.liulishuo.okdownload:sqlite:{latest_version}
// provide okhttp to connect to backend
com.liulishuo.okdownload:okhttp:{latest_version}

Snapshots of the development version are available in Sonatype's snapshots repository, you can include on your gradle project through:

repositories {
    maven { url "https://oss.sonatype.org/content/repositories/snapshots/" }
}

// core
com.liulishuo.okdownload:okdownload:1.0.0-SNAPSHOT
// provide sqlite to store breakpoints
com.liulishuo.okdownload:sqlite:1.0.0-SNAPSHOT
// provide okhttp to connect to backend
com.liulishuo.okdownload:okhttp:1.0.0-SNAPSHOT

Why choose OkDownload?

In fact, OkDownload is FileDownloader2 which extends all preponderance from FileDownloader and beyond, then there is a list:

STABILITY and RELIABLE

• Cover unit tests as far as possible
• Precheck whether free space is enough to store target file when try to pre-allocate length of whole resouce with PreAllocateException and EndCase.PRE_ALLOCATE_FAILED
• Preallocate the length of target file from disk space when start download on very beginning
• Cover the case of there is the same task is running/waiting on OkDownload, another one will be interrupt when required to enqueue/execute
• Cover the case of there is a task is writing to or will be writing to the same file, another one will be interrupted when enqueue/execute or get a filename from the response.
• It will never start completed block again automatically when you resume a task
• It ensures the data on block is sync and persist to the physical disk from the file system when the block-thread is finished
• It ensures the length of data on breakpoint-store is less than or equal to length of real data on physical disk to ensure resuming from breakpoint on the next time never damage file or loss data
• It enables resumable for a task only if it passes ResumeAvailableLocalCheck and ResumeAvailableResponseCheck to ensure breakpoint can't damage the file and the file on backend isn't changed
• Cover the case of file is changed on the backend
• Cover the case of redirect response on okDownload
• Fix the range automatically when a range of block is wrong
• Check whether the local increase length is equal to the content-length on the response to make sure local data is right for each block
• Check the first block and last block especially to cover boundary case
• Ensure cancel operation is effective even if connection is waiting for response, input stream is writing, disconnect is very slow or breakpoint data is synching to the database
• Ensure start operation is effective even if tons of tasks need to be start
• Always saving proceed of each task, so the breakpoint is always resumable even if the process is kill, since your import com.liulishuo.okdownload:sqlite
• Using trial connect to check whether resume available and get instance-length to ensure resume correct and avoid unnecessary TCP window cache before downloading each block
• Using the content length hid on the Content-Range when there isn't valid Content-Length on the response header
• Using the another HEAD method request to check out the certain instance-length when the Content-Range and Transfer-Encoding isn't exist on the response header for the trial connection.
• Check whether the network is really available before start downloading

FLEXIBLE and PERFORMANCE

• Support task priority
• Support using Uri as target file reference
• Support replace Url on BreakpointStore for the case of old Url is discard but its data still resumable
• Combine output-streams of multi-blocks on one handler MultiPointOutputStream
• Provide SpeedCalculator to calculate instance speed or average speed on DownloadListener
• Provide StatusUtil to find status of task or breakpoint-info of task anytime, anywhere
• Provide various callback listeners to meet all requirements you want with DownloadListener1,DownloadListener2,etc..
• Provide function to find running task reference on DownloadDispatcher#findSameTask
• Support one task with several various listeners and manage them easily with UnifiedListenerManager
• Support control batch of tasks with DownloadContext
• Support only download on Wi-Fi network type
• Support control the whole queue size of running task on DownloadDispatcher with DownloadDispatcher.setMaxParallelRunningCount
• Provide DownloadSerialQueue to control dynamic serial download queue.
• [] Provide DownloadQueueListener to listen to the process of batch of tasks
• Support RemitStoreOnSQLite to cover the case of many small tasks raise many useless database operation.
• Support split any count of block to download one task
• Design as light as possible to download without drop performance
• Flexible thread pools on OkDownload to let OkDownload lighter
• Split the network I/O thread pool and file system I/O thread pool to avoid two resources block each other
• Support defines callback downloading process on UI-thread asynchronous or on Block-thread synchronized for each task with DownloadTask.Builder#setAutoCallbackToUIThread
• Support defines the minimum interval millisecond between two callback of DownloadListener#fetchProgress for each task with DownloadTask.Builder#setMinIntervalMillisCallbackProcess
• Support defines read buffer size for each task with DownloadTask.Builder#setReadBufferSize
• Support define flush buffer size for each task with DownloadTask.Builder#setFlushBufferSize
• Support defines sync buffer size for each task with DownloadTask.Builder#setSyncBufferSize
• Support downloading task synchronized with DownloadTask#execute and asynchronous with DownloadTask#enqueue
• Support customize connection handler with implementing your own DownloadConnection and valid it with OkDownload.Builder#connectionFactory
• Support customizes download strategy with implementing your own DownloadStrategy to determine block-count for each task, whether resumable for the eatch task when receiving response, whether need to split to several blocks for eatch task, determine filename of task for eatch task, and valid it with OkDownload.Builder#downloadStrategy
• Support customize processing file strategy with implement your own ProcessFileStrategy to determine how is OkDownload to handle the processing file, whether resumable when get breakpoint info on very begining, and valid it with OkDownload.Builder#processFileStrategy
• Support customize breakpoint store with implement your own BreakpointStore to store all resumable breakpoint infos on your store and valid it with OkDownload.Builder#breakpointStore
• Support customize callback dispatcher with implment your own CallbackDispatcher to handle the event of callback to DownloadListener and valid with Okdownload.Builder#callbackDispatcher
• Support customize download dispatcher with implement your own DownloadDispatcher to control all download task
• Support customize output stream handler with implement your own DownloadOutputStream to control output stream for each task
• Support register one whole download monitor to statistic all key step for each task easily with DownloadMonitor
• Support custom Logger used on okdownload with Util.setLogger() or just want to print log on the console with Util.enableConsoleLog()
• Support cancel and start a bunch of tasks instead of single task with special optimize with DownloadTask.enqueue(tasks, listener) and DownloadTask.cancel(tasks)
• Keep cancel is efficient with let the last i/o operation flying on background and resolve the conflict the next time for same file i/o operation with FileLock class jobs.
• [] Support speed limit
• [] Support download task on independent process with import okdownload-process
• [] Support RxJava
• Support using OkHttp as connection handler with import com.liulishuo.okdownload:okhttp
• [] Support using OkDownload on kotlin style such as DSL with import okdownload-kotlin-enhance
• [] Provide Benchmark on benchmark application
• [] Provide connectionPool library to maintain connection for default DownloadUrlConnection instead of disconnect each time