A basic Java interpretor

javai.py

# Provides a basic command line interpretor for Java
#
# Recognizes import statements and places them accordingly
# All other statements are placed in the body of a main method
# To execute and print a result type "print <statement>"
# Type q/e/quit/exit/close to exit interpretor

import subprocess,re

def writeJava( filename, classname, imports, state, cmdstr ):
	oneIndent = " " * 4
	twoIndent = oneIndent * 2
	fileStr  = "import static java.lang.Math.*;\n" + '\n'.join(imports) + "\nclass " + classname
	fileStr += " {\n" + oneIndent + "public static void main(String[] args) {\n" + twoIndent 
	fileStr += ("\n" + twoIndent).join(state) + "\n" + twoIndent + cmdstr + "\n" + oneIndent + "}\n}"
	with open(filename, "w") as f:
		f.write(fileStr)

def compileJava( filename ):
	result = ""
	try:
		result = subprocess.check_output("javac " + filename, shell=True)
	except subprocess.CalledProcessError:
		result = "ERROR\n"
	return result

def executeJava( filename, classname ):
	result = ""
	try:
		result = subprocess.check_output("java -cp . Test", shell=True)
	except subprocess.CalledProcessError:
		result = "ERROR\n"
	return result

imports = []
state   = []
quitStatements = ["q","e","quit","exit","close"]

importRE = re.compile("^import .*")
printRE  = re.compile("^print (.*)")

filename  = "temp.java"
classname = "Test"

line = raw_input(">> ")
while line.lower() not in quitStatements:
	if line != "":
		entryType = "UNKNOWN"
		cmdstr = ""
		if importRE.match(line):
			entryType = "IMPORT"
			imports.append(line)
		else:
			m = printRE.match(line)
			if m:
				entryType = "CMD"
				cmdstr = "System.out.println(%s);" % m.group(1)
			else:
				entryType = "STATE"
				state.append(line)

		writeJava( filename, classname, imports, state, cmdstr )
		compilerResponse = compileJava( filename )

		if compilerResponse == "":
			if entryType == "CMD":
				print executeJava( filename, classname ),
		else:
			# remove invalid statement from list
			if entryType == "IMPORT":
				imports = imports[:-1]
			elif entryType == "STATE":
				state = state[:-1]

	line = raw_input(">> ")