June 2001
Intermediate to advanced
888 pages
21h 1m
English
You need to read the entire contents of a file into a string.
Use my FileIO.readerToString( )
method.
This is not a common activity in Java, but there will be times when
you really want to do it. For example, you might want to load a file
into a “text area” in a GUI. Or process an entire file
looking for multiline regular expressions (as in Section 4.13). Even though there’s nothing in the
standard API to do this, it’s still easy to accomplish with the
readerToString( ) method in
com.darwinsys.util.FileIO. You just say something
like the following:
Reader is = new FileReader(theFileName); String input = FileIO.readerToString(is);
The readerToString( ) method is fairly simple,
based on what you’ve already seen:
// Part of com.darwinsys.util/FileIO.java
/** Read the entire content of an Reader into a String */
public static String readerToString(Reader is) throws IOException {
StringBuffer sb = new StringBuffer( );
char[] b = new char[BLKSIZ];
int n;
// Read a block. If it gets any chars, append them.
while ((n = is.read(b)) > 0) {
sb.append(b, 0, n);
}
// Only construct the String object once, here.
return sb.toString( );
}
/** Read the content of a Stream into a String */
public static String inputStreamToString(InputStream is)
throws IOException {
return readerToString(new InputStreamReader(is));
}