Package com.chilkatsoft.chilkat2

Class Stream

java.lang.Object
com.chilkatsoft.chilkat2.ChilkatObject
com.chilkatsoft.chilkat2.Stream
All Implemented Interfaces:
AutoCloseable
public class Stream extends ChilkatObject
<section class="stream-summary">

Read, write, pipe, monitor, and control byte or text streams.

Chilkat.Stream is a general-purpose streaming object for moving data between sources and sinks without requiring the entire payload to be handled at once. A stream can read from files, byte arrays, strings, or other sources; write to files, memory, BinData, StringBuilder, or other sinks; handle binary and text data; apply character-set rules for strings; process file parts; track bytes sent and received; and support timeouts, polling, aborts, async task integration, and end-of-stream handling.

File and memory sources

Stream from a source file, byte array, string, or selected file part without manually loading or copying all data first.

File and object sinks

Write streamed data to a sink file, append to an existing file, or output to BinData, StringBuilder, bytes, or strings.

Binary reads and writes

Read or write raw bytes, fixed byte counts, encoded byte strings, individual bytes, or BinData content.

Text streaming

Read and write strings using StringCharset, optionally use a BOM, and read text until CRLF or a matching delimiter.

Timeouts and polling

Control read and write wait behavior, poll for immediately available data, and inspect read or write failure reasons.

Progress and lifecycle

Track bytes sent and received, detect end-of-stream or write-closed state, reset streams, close writing, and abort long-running operations.

Common pattern: Configure the stream's source and sink, set the character set or chunk size if needed, then read or write using the method that matches the data type: bytes, encoded bytes, strings, BinData, or StringBuilder. Check EndOfStream, ReadFailReason, WriteFailReason, NumReceived, NumSent, and LastErrorText to understand stream progress and failures.

Timeout note: For ReadTimeoutMs, a value of 0 means a polling read, not an infinite timeout. For WriteTimeoutMs, 0 means return immediately if the stream cannot be written to right away.

</section>

Event-capable: long-running methods report progress through a ProgressListener installed with setProgressListener(ProgressListener), onAbortCheck(BooleanSupplier), onPercentDone(IntPredicate) or onProgressInfo(BiConsumer).

Instances hold a native Chilkat object: close them with ChilkatObject.close() (try-with-resources) when done; an unclosed instance is freed when it becomes unreachable.

See Also:
Online reference

  • Constructor Details

    • Stream

      public Stream()
      Creates a new Stream object.

  • Method Details

    • getAbortCurrent

      public boolean getAbortCurrent()
      When set to true, causes the currently running method to abort. Methods that always finish quickly (i.e.have no length file operations or network communications) are not affected. If no method is running, then this property is automatically reset to false when the next method is called. When the abort occurs, this property is reset to false. Both synchronous and asynchronous method calls can be aborted. (A synchronous method call could be aborted by setting this property from a separate thread.)
      Returns:
      the value of the AbortCurrent property

    • setAbortCurrent

      public void setAbortCurrent​(boolean value)
      Sets the AbortCurrent property; see getAbortCurrent().
      Parameters:
      value - the new value

    • getCanRead

      public boolean getCanRead()
      true if the stream supports reading. Otherwise false.

      Note: A stream that supports reading, which has already reached the end-of-stream, will still have a CanRead value of true. This property indicates the stream's inherent ability, and not whether or not the stream can be read at a particular moment in time.

      Returns:
      the value of the CanRead property (read-only)

    • getCanWrite

      public boolean getCanWrite()
      true if the stream supports writing. Otherwise false.

      Note: A stream that supports writing, which has already been closed for write, will still have a CanWrite value of true. This property indicates the stream's inherent ability, and not whether or not the stream can be written at a particular moment in time.

      Returns:
      the value of the CanWrite property (read-only)

    • getDataAvailable

      public boolean getDataAvailable()
      true if it is known for sure that data is ready and waiting to be read. false if it is not known for sure (it may be that data is immediately available, but reading the stream with a ReadTimeoutMs of 0, which is to poll the stream, is the way to find out).
      Returns:
      the value of the DataAvailable property (read-only)

    • getDefaultChunkSize

      public int getDefaultChunkSize()
      The default internal chunk size for reading or writing. The default value is 65536. If this property is set to 0, it will cause the default chunk size (65536) to be used. Note: The chunk size can have significant performance impact. If performance is an issue, be sure to experiment with different chunk sizes.
      Returns:
      the value of the DefaultChunkSize property

    • setDefaultChunkSize

      public void setDefaultChunkSize​(int value)
      Sets the DefaultChunkSize property; see getDefaultChunkSize().
      Parameters:
      value - the new value

    • getEndOfStream

      public boolean getEndOfStream()
      true if the end-of-stream has already been reached. When the stream has already ended, all calls to Read* methods will return false with the ReadFailReason set to 3 (already at end-of-stream).
      Returns:
      the value of the EndOfStream property (read-only)

    • getHeartbeatMs

      public int getHeartbeatMs()
      The interval in milliseconds between each AbortCheck event callback, which enables an application to abort certain method calls before they complete. By default, HeartbeatMs is set to 0, meaning no AbortCheck event callbacks will trigger.
      Returns:
      the value of the HeartbeatMs property

    • setHeartbeatMs

      public void setHeartbeatMs​(int value)
      Sets the HeartbeatMs property; see getHeartbeatMs().
      Parameters:
      value - the new value

    • getIsWriteClosed

      public boolean getIsWriteClosed()
      true if the stream is closed for writing. Once closed, no more data may be written to the stream.
      Returns:
      the value of the IsWriteClosed property (read-only)

    • getLength

      public long getLength()
      The length (in bytes) of the stream's source. If unknown, then this property will have a value of -1. This property may be set by the application if it knows in advance the length of the stream.
      Returns:
      the value of the Length property

    • setLength

      public void setLength​(long value)
      Sets the Length property; see getLength().
      Parameters:
      value - the new value

    • getLength32

      public int getLength32()
      The length (in bytes) of the stream's source. If unknown, then this property will have a value of -1. This property may be set by the application if it knows in advance the length of the stream.

      Setting this property also sets the Length property (which is a 64-bit integer).

      Returns:
      the value of the Length32 property

    • setLength32

      public void setLength32​(int value)
      Sets the Length32 property; see getLength32().
      Parameters:
      value - the new value

    • getNumReceived

      public long getNumReceived()
      The number of bytes received by the stream.
      Returns:
      the value of the NumReceived property (read-only)

    • getNumSent

      public long getNumSent()
      The number of bytes sent by the stream.
      Returns:
      the value of the NumSent property (read-only)

    • getReadFailReason

      public int getReadFailReason()
      This property is automatically set when a Read* method is called. It indicates the reason for failure. Possible values are:
        0>
      1. No failure (success)
      2. Timeout, or no data is immediately available for a polling read.
      3. Aborted by an application callback.
      4. Already at end-of-stream.
      5. Fatal stream error.
      6. Out-of-memory error (this is very unlikely).

      Returns:
      the value of the ReadFailReason property (read-only)

    • getReadTimeoutMs

      public int getReadTimeoutMs()
      The maximum number of seconds to wait while reading. The default value is 30 seconds (i.e. 30000ms). A value of 0 indicates a poll. (A polling read is to return with a timeout if no data is immediately available.)

      Important: For most Chilkat timeout related properties, a value of 0 indicates an infinite timeout. For this property, a value of 0 indicates a poll. If setting a timeout related property (or method argument) to zero, be sure to understand if 0 means wait forever or poll.

      The timeout value is not a total timeout. It is the maximum time to wait while no additional data is forthcoming.

      Returns:
      the value of the ReadTimeoutMs property

    • setReadTimeoutMs

      public void setReadTimeoutMs​(int value)
      Sets the ReadTimeoutMs property; see getReadTimeoutMs().
      Parameters:
      value - the new value

    • getSinkFile

      public String getSinkFile()
      Sets the sink to the path of a file. The file does not need to exist at the time of setting this property. The sink file will be automatically opened on demand, when the stream is first written.

      Note: This property takes priority over other potential sinks. Make sure this property is set to an empty string if the stream's sink is to be something else.

      Returns:
      the value of the SinkFile property

    • setSinkFile

      public void setSinkFile​(String value)
      Sets the SinkFile property; see getSinkFile().
      Parameters:
      value - the new value (not null)

    • getSinkFileAppend

      public boolean getSinkFileAppend()
      If true, the stream appends to the SinkFile rather than truncating and re-writing the sink file. The default value is false.
      Returns:
      the value of the SinkFileAppend property

    • setSinkFileAppend

      public void setSinkFileAppend​(boolean value)
      Sets the SinkFileAppend property; see getSinkFileAppend().
      Parameters:
      value - the new value

    • getSourceFile

      public String getSourceFile()
      Sets the source to the path of a file. The file does not need to exist at the time of setting this property. The source file will be automatically opened on demand, when the stream is first read.

      Note: This property takes priority over other potential sources. Make sure this property is set to an empty string if the stream's source is to be something else.

      Returns:
      the value of the SourceFile property

    • setSourceFile

      public void setSourceFile​(String value)
      Sets the SourceFile property; see getSourceFile().
      Parameters:
      value - the new value (not null)

    • getSourceFilePart

      public int getSourceFilePart()
      If the source is a file, then this property can be used to stream one part of the file. The SourceFilePartSize property defines the size (in bytes) of each part. The SourceFilePart and SourceFilePartSize have default values of 0, which means the entire SourceFile is streamed.

      This property is a 0-based index. For example, if the SourceFilePartSize is 1000, then part 0 is for bytes 0 to 999, part 1 is for bytes 1000 to 1999, etc.

      Returns:
      the value of the SourceFilePart property

    • setSourceFilePart

      public void setSourceFilePart​(int value)
      Sets the SourceFilePart property; see getSourceFilePart().
      Parameters:
      value - the new value

    • getSourceFilePartSize

      public int getSourceFilePartSize()
      If the source is a file, then this property, in conjunction with the SourceFilePart property, can be used to stream a single part of the file. This property defines the size (in bytes) of each part. The SourceFilePart and SourceFilePartSize have default values of 0, which means that by default, the entire SourceFile is streamed.
      Returns:
      the value of the SourceFilePartSize property

    • setSourceFilePartSize

      public void setSourceFilePartSize​(int value)
      Sets the SourceFilePartSize property; see getSourceFilePartSize().
      Parameters:
      value - the new value

    • getStringBom

      public boolean getStringBom()
      If true, then include the BOM when creating a string source via SetSourceString where the charset is utf-8, utf-16, etc. (The term BOM stands for Byte Order Mark, also known as the preamble.) Also, if true, then include the BOM when writing a string via the WriteString method. The default value of this property is false.
      Returns:
      the value of the StringBom property

    • setStringBom

      public void setStringBom​(boolean value)
      Sets the StringBom property; see getStringBom().
      Parameters:
      value - the new value

    • getStringCharset

      public String getStringCharset()
      Indicates the expected character encoding, such as utf-8, windows-1256, utf-16, etc. for methods that read text such as: ReadString, ReadToCRLF, ReadUntilMatch. Also controls the character encoding when writing strings with the WriteString method. The supported charsets are indicated at the link below.

      The default value is utf-8.

      Returns:
      the value of the StringCharset property

    • setStringCharset

      public void setStringCharset​(String value)
      Sets the StringCharset property; see getStringCharset().
      Parameters:
      value - the new value (not null)

    • getWriteFailReason

      public int getWriteFailReason()
      This property is automatically set when a Write* method is called. It indicates the reason for failure. Possible values are:
        0>
      1. No failure (success)
      2. Timeout, or unable to immediately write when the WriteTimeoutMs is 0.
      3. Aborted by an application callback.
      4. The stream has already ended.
      5. Fatal stream error.
      6. Out-of-memory error (this is very unlikely).

      Returns:
      the value of the WriteFailReason property (read-only)

    • getWriteTimeoutMs

      public int getWriteTimeoutMs()
      The maximum number of seconds to wait while writing. The default value is 30 seconds (i.e. 30000ms). A value of 0 indicates to return immediately if it is not possible to write to the sink immediately.
      Returns:
      the value of the WriteTimeoutMs property

    • setWriteTimeoutMs

      public void setWriteTimeoutMs​(int value)
      Sets the WriteTimeoutMs property; see getWriteTimeoutMs().
      Parameters:
      value - the new value

    • readBd

      public void readBd​(BinData binData)
      Read as much data as is immediately available on the stream. If no data is immediately available, it waits up to ReadTimeoutMs milliseconds for data to arrive. The incoming data is appended to binData.
      Parameters:
      binData - the binData argument (not null)
      Throws:
      ChilkatException - if the operation fails; ChilkatException.getLastErrorText() says why

    • readBytesENC

      public String readBytesENC​(String encoding)
      The same as ReadBytes, except returns the received bytes in encoded string form. The encoding argument indicates the encoding, which can be base64, hex, or any of the multitude of encodings indicated in the link below.
      Parameters:
      encoding - the encoding argument (not null)
      Returns:
      the result (never null)
      Throws:
      ChilkatException - if the operation fails; ChilkatException.getLastErrorText() says why

    • readNBytesENC

      public String readNBytesENC​(int numBytes, String encoding)
      The same as ReadNBytes, except returns the received bytes in encoded string form. The encoding argument indicates the encoding, which can be base64, hex, or any of the multitude of encodings indicated in the link below.
      Parameters:
      numBytes - the numBytes argument
      encoding - the encoding argument (not null)
      Returns:
      the result (never null)
      Throws:
      ChilkatException - if the operation fails; ChilkatException.getLastErrorText() says why

    • readSb

      public void readSb​(StringBuilder sb)
      Read as much data as is immediately available on the stream. If no data is immediately available, it waits up to ReadTimeoutMs milliseconds for data to arrive. The data is appended to sb. The incoming bytes are interpreted according to the StringCharset property. For example, if utf-8 bytes are expected, then StringCharset should be set to utf-8 prior to calling ReadSb.
      Parameters:
      sb - the sb argument (not null)
      Throws:
      ChilkatException - if the operation fails; ChilkatException.getLastErrorText() says why

    • readString

      public String readString()
      Read as much data as is immediately available on the stream. If no data is immediately available, it waits up to ReadTimeoutMs milliseconds for data to arrive. The data is returned as a string. The incoming bytes are interpreted according to the StringCharset property. For example, if utf-8 bytes are expected, then StringCharset should be set to utf-8 prior to calling ReadString.
      Returns:
      the result (never null)
      Throws:
      ChilkatException - if the operation fails; ChilkatException.getLastErrorText() says why

    • readToCRLF

      public String readToCRLF()
      Reads the stream until a CRLF is received. If no data is immediately available, it waits up to ReadTimeoutMs milliseconds for data to arrive. The data is returned as a string. The incoming bytes are interpreted according to the StringCharset property. For example, if utf-8 bytes are expected, then StringCharset should be set to utf-8 prior to calling ReadString.

      Note: If the end-of-stream is reached prior to receiving the CRLF, then the remaining data is returned, and the ReadFailReason property will be set to 3 (to indicate end-of-file). This is the only case where as string would be returned that does not end with CRLF.

      Returns:
      the result (never null)
      Throws:
      ChilkatException - if the operation fails; ChilkatException.getLastErrorText() says why

    • readUntilMatch

      public String readUntilMatch​(String matchStr)
      Reads the stream until the string indicated by matchStr is received. If no data is immediately available, it waits up to ReadTimeoutMs milliseconds for data to arrive. The data is returned as a string. The incoming bytes are interpreted according to the StringCharset property. For example, if utf-8 bytes are expected, then StringCharset should be set to utf-8 prior to calling ReadString.

      Note: If the end-of-stream is reached prior to receiving the match string, then the remaining data is returned, and the ReadFailReason property will be set to 3 (to indicate end-of-file). This is the only case where as string would be returned that does not end with the desired match string.

      Parameters:
      matchStr - the matchStr argument (not null)
      Returns:
      the result (never null)
      Throws:
      ChilkatException - if the operation fails; ChilkatException.getLastErrorText() says why

    • reset

      public void reset()
      Resets the stream. If a source or sink is open, then it is closed. Properties such as EndOfStream and IsWriteClose are reset to default values.

    • setSourceString

      public void setSourceString​(String srcStr, String charset)
      Sets the stream's source to the contents of srcStr. The charset indicates the character encoding to be used for the byte representation of the srcStr.
      Parameters:
      srcStr - the srcStr argument (not null)
      charset - the charset argument (not null)
      Throws:
      ChilkatException - if the operation fails; ChilkatException.getLastErrorText() says why

    • writeBd

      public void writeBd​(BinData binData)
      Writes the contents of binData to the stream.
      Parameters:
      binData - the binData argument (not null)
      Throws:
      ChilkatException - if the operation fails; ChilkatException.getLastErrorText() says why

    • writeByte

      public void writeByte​(int byteVal)
      Writes a single byte to the stream. The byteVal must have a value from 0 to 255.
      Parameters:
      byteVal - the byteVal argument
      Throws:
      ChilkatException - if the operation fails; ChilkatException.getLastErrorText() says why

    • writeBytesENC

      public void writeBytesENC​(String byteData, String encoding)
      Writes binary bytes to a stream. The byte data is passed in encoded string form, where the encoding can be base64, hex, or any of the supported binary encodings listed at the link below.
      Parameters:
      byteData - the byteData argument (not null)
      encoding - the encoding argument (not null)
      Throws:
      ChilkatException - if the operation fails; ChilkatException.getLastErrorText() says why

    • writeClose

      public void writeClose()
      Indicates that no more data will be written to the stream.
      Throws:
      ChilkatException - if the operation fails; ChilkatException.getLastErrorText() says why

    • writeSb

      public void writeSb​(StringBuilder sb)
      Writes the contents of sb to the stream. The actual bytes written are the byte representation of the string as indicated by the StringCharset property. For example, to write utf-8 bytes, first set StringCharset equal to utf-8 and then call WriteSb.
      Parameters:
      sb - the sb argument (not null)
      Throws:
      ChilkatException - if the operation fails; ChilkatException.getLastErrorText() says why

    • writeString

      public void writeString​(String str)
      Writes a string to a stream. The actual bytes written are the byte representation of the string as indicated by the StringCharset property. For example, to write utf-8 bytes, first set StringCharset equal to utf-8 and then call WriteString.
      Parameters:
      str - the str argument (not null)
      Throws:
      ChilkatException - if the operation fails; ChilkatException.getLastErrorText() says why

    • setProgressListener

      public void setProgressListener​(ProgressListener listener)
      Installs the listener that receives this object's progress events (abortCheck, percentDone, progressInfo) during its long-running methods; replaces any listener or lambda installed before; null removes it.
      Parameters:
      listener - the listener, or null
      Throws:
      IllegalStateException - if called from inside one of this object's own callbacks

    • getProgressListener

      public ProgressListener getProgressListener()
      Returns the installed listener, or null.
      Returns:
      the listener installed with setProgressListener(ProgressListener) or one of the on... methods

    • onAbortCheck

      public void onAbortCheck​(BooleanSupplier callback)
      Installs a listener whose only callback is abortCheck: called every HeartbeatMs milliseconds during a long-running method; return true to abort it. Replaces any listener installed before.
      Parameters:
      callback - the callback, or null to remove the listener

    • onPercentDone

      public void onPercentDone​(IntPredicate callback)
      Installs a listener whose only callback is percentDone: called with the completion percentage (0..100) as a long-running method progresses; return true to abort it. Replaces any listener installed before.
      Parameters:
      callback - the callback, or null to remove the listener

    • onProgressInfo

      public void onProgressInfo​(BiConsumer<String,​String> callback)
      Installs a listener whose only callback is progressInfo: called with a name/value pair of progress information as a long-running method proceeds. Replaces any listener installed before.
      Parameters:
      callback - the callback, or null to remove the listener