c# - Handling exceptions from a method that could fire multiple exceptions -

i have api class using memorystream , gzipstream classes compress , decompress string byte array.

using these 2 classes number of exceptions may throws , wondering best method of handling thrown exception api. in case be better wrap each of exception own custom exception or preferable capture each individual exception in calling code?

i suppose question not limited particular use case more general exception handling best practices.

/// <summary> /// compress string using sharplibzip gzip compression routines /// </summary> /// <param name="s">string object compress</param> /// <returns>a gzip compressed byte array of passed in string</returns> /// <exception cref="helper.core.compression.stringcompressionexception">throw when compression memory stream fails </exception> /// <exception cref="system.argumentnullexception">throw when string parameter null</exception> /// <exception cref="system.argumentexception">throw when string parameter empty</exception> public async task<byte[]> compressstringasync(string s) {     if (s == null) throw new argumentnullexception("s");     if (string.isnullorwhitespace(s)) throw new argumentexception("s");      byte[] compressed = null;      try     {         using (memorystream outstream = new memorystream())         {             using (gzipstream tinystream = new gzipstream(outstream,compressionmode.compress))             {                 using (memorystream memstream = new memorystream(encoding.utf8.getbytes(s)))                 {                     await memstream.copytoasync(tinystream);                 }             }             compressed = outstream.toarray();         }         return compressed;     }     catch (argumentnullexception ex)     {         throw new stringcompressionexception("argument null", ex);     }     catch (encoderfallbackexception ex)     {         throw new stringcompressionexception("stream encoding failure", ex);     }     catch (argumentexception ex)     {         throw new stringcompressionexception("argument not valid", ex);     }     catch (objectdisposedexception ex)     {         throw new stringcompressionexception("a stream disposed", ex);     }     catch (notsupportedexception ex)     {         throw new stringcompressionexception("action not supported", ex);     } } 

here post on catching base exceptions.

you're taking advantage of "inner exception" functionality of exception base class in example code show, why not take way?

you don't need re-write message of inner exception, wrap exception in stringcompressionexception class. if client catches exception wants know more detailed information failure, can check inner exception.

that makes code lot simpler:

try {     using (memorystream outstream = new memorystream())     {         using (gzipstream tinystream = new gzipstream(outstream,compressionmode.compress))         {             using (memorystream memstream = new memorystream(encoding.utf8.getbytes(s)))             {                 await memstream.copytoasync(tinystream);             }         }         compressed = outstream.toarray();     }     return compressed; } catch (exception ex) {     throw new stringcompressionexception("compressing string failed; see inner exception details.", ex); } 

also keep in mind exception message strings not localize easily, they're not should displaying end user anyway. they're debugging aid, "see inner exception details" works fine. maintenance programmers know that.