$ java -Xmx64m ReadAllFail readAllLines medium.log
OutOfMemoryError: Java heap space
$ java -Xmx64m ReadAllFail readString medium.log
OutOfMemoryError: Java heap space
$ java -Xmx64m ReadAllFail readAllBytes medium.log
OutOfMemoryError: Java heap space
$ java -Xmx64m ReadAllFail readAllLines big.log
OutOfMemoryError: Java heap space
$ java -Xmx64m ReadAllFail readString big.log
OutOfMemoryError: Required array size too large
$ java -Xmx64m ReadAllFail readAllBytes big.log
OutOfMemoryError: Required array size too large

How much heap does the 200 MB file need? (readAllLines, then readString)
readAllLines  -Xmx256m  OutOfMemoryError: Java heap space
readString    -Xmx256m  survived: 200000016 chars
readAllLines  -Xmx512m  survived: 1378768 lines
readString    -Xmx512m  survived: 200000016 chars
readAllLines  -Xmx1g    survived: 1378768 lines
readString    -Xmx1g    survived: 200000016 chars
readAllLines  -Xmx2g    survived: 1378768 lines
readString    -Xmx2g    survived: 200000016 chars