Streams

Overview

Module

• package: org.eclipse.dirigible.sdk.io
• source: io/Streams.java

Stream-shaped I/O — read text / bytes from an InputStream, write to an OutputStream, copy between them, build in-memory buffers via ByteArrayInputStream / ByteArrayOutputStream. Useful when wiring together sources and sinks supplied by different APIs (a multipart upload feeding a ZIP entry, the platform repository feeding an HTTP response).

copyLarge(InputStream, OutputStream) should be preferred over plain copy(InputStream, OutputStream) for files larger than a few MB — it uses a bigger internal buffer and reports a long byte count via the underlying facade.

Key Features:

• Read primitives: read, readBytes, readText over any InputStream.
• Write primitives: write a single byte, writeBytes (string-encoded), writeText over any OutputStream.
• Copying: copy for small payloads, copyLarge for multi-MB streams.
• In-memory buffers: Factory methods for ByteArrayInputStream / ByteArrayOutputStream.
• Resource access: Load a classpath resource as a ByteArrayInputStream.

Example Usage:

import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import org.eclipse.dirigible.sdk.io.Streams;

try (InputStream in = Streams.getResourceAsByteArrayInputStream("/img/logo.png")) {
    ByteArrayOutputStream out = Streams.createByteArrayOutputStream();
    Streams.copy(in, out);
    byte[] data = Streams.getBytes(out);
}

Methods

read()

Reads a single byte from the stream and returns it as an int, or -1 on end-of-stream.

public static int read(InputStream input) throws IOException;

Parameter	Type	Description
input	InputStream	The stream to read from.

Returns

• Type: int
• Description: The byte read (0–255), or -1 at end-of-stream.

readBytes()

Reads all remaining bytes from the stream into a byte[].

public static byte[] readBytes(InputStream input) throws IOException;

Parameter	Type	Description
input	InputStream	The stream to drain.

Returns

• Type: byte[]
• Description: All bytes read from the stream.

readText()

Reads the stream contents fully as text using the platform default encoding.

public static String readText(InputStream input) throws IOException;

Parameter	Type	Description
input	InputStream	The stream to read.

Returns

• Type: String
• Description: The decoded text content.

close()

Closes the given stream. Overloads cover both InputStream and OutputStream.

public static void close(InputStream input) throws IOException;
public static void close(OutputStream output) throws IOException;

Parameter	Type	Description
input	InputStream	The input stream to close.
output	OutputStream	The output stream to close.

Returns

• Type: void

write()

Writes a single byte (low 8 bits of value) to the output stream.

public static void write(OutputStream output, int value) throws IOException;

Parameter	Type	Description
output	OutputStream	The output stream.
value	int	The byte value to write (low 8 bits used).

Returns

• Type: void

writeBytes()

Writes the bytes encoded by the given string input to the output stream.

public static void writeBytes(OutputStream output, String input) throws IOException;

Parameter	Type	Description
output	OutputStream	The output stream.
input	String	The string-encoded byte input.

Returns

• Type: void

writeText()

Writes a string of text to the output stream using the platform default encoding.

public static void writeText(OutputStream output, String value) throws IOException;

Parameter	Type	Description
output	OutputStream	The output stream.
value	String	The text to write.

Returns

• Type: void

copy()

Copies all bytes from the input stream to the output stream. Suitable for small payloads — prefer copyLarge for multi-MB transfers.

public static void copy(InputStream input, OutputStream output) throws IOException;

Parameter	Type	Description
input	InputStream	The source stream.
output	OutputStream	The sink stream.

Returns

• Type: void

copyLarge()

Copies all bytes from the input stream to the output stream using a larger internal buffer. Preferred for files above a few MB.

public static void copyLarge(InputStream input, OutputStream output) throws IOException;

Parameter	Type	Description
input	InputStream	The source stream.
output	OutputStream	The sink stream.

Returns

• Type: void

createByteArrayInputStream()

Creates a new in-memory ByteArrayInputStream. Overloads cover an explicit byte[], a String-encoded buffer, and an empty stream.

public static ByteArrayInputStream createByteArrayInputStream(byte[] input) throws IOException;
public static ByteArrayInputStream createByteArrayInputStream(String input) throws IOException;
public static ByteArrayInputStream createByteArrayInputStream() throws IOException;

Parameter	Type	Description
input	byte[]	The bytes to wrap. Optional.
input	String	The string-encoded bytes to wrap. Optional.

Returns

• Type: ByteArrayInputStream
• Description: A new in-memory input stream.

createByteArrayOutputStream()

Creates a new in-memory ByteArrayOutputStream to accumulate bytes.

public static ByteArrayOutputStream createByteArrayOutputStream() throws IOException;

Returns

• Type: ByteArrayOutputStream
• Description: A new in-memory output stream.

getBytes()

Returns the bytes accumulated in a ByteArrayOutputStream.

public static byte[] getBytes(ByteArrayOutputStream output) throws IOException;

Parameter	Type	Description
output	ByteArrayOutputStream	The buffer to drain.

Returns

• Type: byte[]
• Description: The accumulated bytes.

getText()

Returns the accumulated bytes of a ByteArrayOutputStream decoded as text using the platform default encoding.

public static String getText(ByteArrayOutputStream output) throws IOException;

Parameter	Type	Description
output	ByteArrayOutputStream	The buffer to drain.

Returns

• Type: String
• Description: The accumulated bytes decoded as text.

getResourceAsByteArrayInputStream()

Loads a classpath resource at the given path and returns its contents as a ByteArrayInputStream.

public static ByteArrayInputStream getResourceAsByteArrayInputStream(String path) throws IOException;

Parameter	Type	Description
path	String	The classpath resource path.

Returns

• Type: ByteArrayInputStream
• Description: A stream over the resource contents.