Java Download File From Url To Byte Array [TOP]
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I have to store some constant values (UUIDs) in byte array form in java, and I'm wondering what the best way to initialize those static arrays would be. This is how I'm currently doing it, but I feel like there must be a better way.
The bytes of the resulting string differs depending on what charset you use. new String(bytes) and new String(bytes, Charset.forName("utf-8")) and new String(bytes, Charset.forName("utf-16")) will all have different byte arrays when you call String#getBytes() (depending on the default charset)
Using new String(byOriginal) and converting back to byte[] using getBytes() doesn't guarantee two byte[] with equal values. This is due to a call to StringCoding.encode(..) which will encode the String to Charset.defaultCharset(). During this encoding, the encoder might choose to replace unknown characters and do other changes. Hence, using String.getBytes() might not return an equal array as you've originally passed to the constructor.
is correct it throws a UnsupportedEncodingException which forces you to deal with a checked exception. You can use as an alternative another constructor since Java 1.6 to convert a byte array into a String:
I did notice something that is not in any of the answers. You can cast each of the bytes in the byte array to characters, and put them in a char array. Then the string is new String(cbuf) where cbuf is the char array. To convert back, loop through the string casting each of the chars to bytes to put into a byte array, and this byte array will be the same as the first.
While base64 encoding is safe and one could argue "the right answer", I arrived here looking for a way to convert a Java byte array to/from a Java String as-is. That is, where each member of the byte array remains intact in its String counterpart, with no extra space required for encoding/transport.
AFAIK, Array is equivalent to java's Byte[] (the boxed byte). If you want primitive byte array, use ByteArray. Also, as compiler mentioned, you can't use assign in the while condition.So, converted code may look like this:
That means you are converting to a string somewhere. That is the problem. You cannot use curly brace parameters in your SQL with these, as curly braces perform string substitution. You must use question mark parameters in a scripted "Prep" query, or value parameters (the colon prefixed named parameters) in a Named Query. That's the only way to push a byte array (or any other values) to SQL without corrupting it in translation.
Note that the size of a byte array is fixed and cannot be changed after it is created. If you need to change the size of the array, you can create a new array with the desired size and copy the elements of the old array to the new array using the System.arraycopy() method.
The RFC is expecting a table of type TBL1024 which is basically a table of xstring values. The Java proxy interprets this SAP table as a byte array. This is my problem... I cannot seem to "break" up the Byte array into lines of 1024 lengt and send it back to SAP. All that is happening currently is that the byte array creates a singe line in the TBL1024 that consists of only the first 1024 bytes in the array... This means that only the first 1024 bytes of my document is being saved - making it corrupt.
InputStream itself is already an abstraction of a stream of bytes that can be read. A ByteArrayInputStream is a specific implementation of InputStream that gets the bytes in the stream from an underlying byte array (that's the one the constructor wants you to supply).
For your method here, there is probably not much benefit in having a ByteArrayInputStream, an InputStream definitely would, as clients could then pass all kinds of byte sources to your method, whereas otherwise they'd have to read them in an array themselves. A stream also has the advantage that you don't have to have all bytes in memory at the same time, which is convenient if the size of the data is large and can easily be handled in small chunks.
Learn to convert byte[] array to String and convert String to byte[] array in Java with examples. Conversion between byte array and string may be used in many cases including IO operations, generating secure hashes etc.
If successful, it returns the value of the parsed long type. On failure, it throws a parse exception.Parameters:b - the byte array to parse.off - the offset in the byte array to use when parsing.Returns:the parsed long value.Throws:ParseException - if there are not sufficient bytes.parseIntpublic static int parseInt(byte[] b, int off) throws ParseExceptionParse an integer primitive type in the provided bytes. It looks for 4 bytes in the provided bytes starting at the specified off. If successful, it returns the value of the parsed integer type. On failure, it throws a parse exception.Parameters:b - the byte array to parse.off - the offset in the byte array to use when parsing.Returns:the parsed integer value.Throws:ParseException - if there are not sufficient bytes.parseShortpublic static short parseShort(byte[] b, int off)Parse a short primitive type in the provided bytes. It looks for 2 bytes in the provided bytes starting at the specified off. If successful, it returns the value of the parsed short type. On failure, it throws a parse exception.Parameters:b - the byte array to parse.off - the offset in the byte array to use when parsing.Returns:the parsed short value.Throws:ParseException - if there are not sufficient bytes.parseUnsignedShortpublic static int parseUnsignedShort(byte[] b, int off)Equivalent to parseShort(byte[], int) except the 2 bytes are treated as an unsigned value (and thus returned as an into to avoid overflow).writeUnsignedShortpublic static void writeUnsignedShort(DataOutput out, int uShort) throws IOExceptionWrites 2 bytes containing the unsigned value uShort to out.Throws:IOExceptionparseBytepublic static byte parseByte(byte[] b, int off)Parse a single byte in the provided bytes. It looks for a byte in the provided bytes starting at the specified off. If successful, it returns the value of the parsed byte. On failure, it throws a parse exception.Parameters:b - the byte array to parse.off - the offset in the byte array to use when parsing.Returns:the parsed byte value.Throws:ParseException - if there are not sufficient bytes.Skip navigation links
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Use this as a safe way to log a limited amount of content. As content is written to the stream, it is stored as a byte array, up to the maximum number of bytes limit that was set in the constructor. Note that if the maximum limit is set too high, it risks an OutOfMemoryError on low-memory devices. This class also keeps track of the total number of bytes written, regardless of whether they were logged. On #close(), it then logs two records to the specified logger and logging level: the total number of bytes written, and the bounded content logged (assuming charset "UTF-8"). Any control characters are stripped out of the content.
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