Question

Hello Stack Overflow community,

I am doing multistep processing on some data I am receiving with a java Servlet. The current process I have is that I input the files to a server using Apache File Upload and convert them to a File. Then once input1 is populated with data, I run through a flow similar to this (where the process functions are xsl transforms):

File input1 = new File(FILE_NAME);  // <---this is populated with data
File output1 = new File(TEMP_FILE); // <---this is the temporary file

InputStream read = new FileInputStream(input1); 
OuputStream out = new FileOutputStream(output1);

process1ThatReadsProcessesOutputs( read, out);

out.close();
read.close();

//this is basically a repeat of the above process!
File output2 = new File(RESULT_FILE);  // <--- This is the result file 
InputStream read1 = new FileInputStream(output1);
OutputStream out1 = new FileOutputStream(output2);
Process2ThatReadsProcessesOutputs( read1, out1);
read1.close();
out1.close();
…

So my question is if there is a better way to do this so I do not have to create those temporary Files and recreate streams to those Files? (I am assuming I am incurring a decent performace penatly)

I saw this Most Efficient Way to create InputStream from OutputStream but I am not sure if this is the best route to go…

Answer 1

Just replace FileOutputStream to ByteArrayInputStream vice/versa.

Example:

ByteArrayOutputStream out = new ByteArrayOutputStream();
ByteArrayInputStream in = new ByteArrayInputStream(out.toByteArray());