Not losing output in java batch jobs due to too wide lines.

Hi.

All my java stuff on the i run in batch so I have experimented a bit with how to approach the fact that the linewidth is 132 characters or something like that and no more - everything written after the 132'th column vanishes.

I ended up writing this small class which I call ONCE as the first thing in the program (even before the logging system gets initialized). It works by putting a wrapper around both System.out and System.err which counts where you are on the current line and outputs a newline and indents when the line gets too long. The value of 127 in width and 3 in indent works well viewing with the client access emulator.

====
public class SystemOutErrHelper {

private static PrintStream out;
private static PrintStream err;

/**
* Set up System.out and System.err to be wrapped and indented to be
* readable even on the AS/400 QPRINT device at 132x27 (text written over
* this edge is truncated and discarded).
*
* <br/>
*
* It is recommended that this is the first line called in the main class.
* If logging is active for that class, do NOT initialize it in the field
* definition, but do it after this call "inline" in main().
*/
public static void wrapAndIndentOnAS400() {
wrapAndIndent(127, 3);
}

private static void wrapAndIndent(int wrapColumn, int indent) {
err = System.err;
out = System.out;

System.setErr(new WrapAndIndentPrintStream(err, wrapColumn, indent).getStream());
System.setOut(new WrapAndIndentPrintStream(out, wrapColumn, indent).getStream());
}
}
===
public class WrapAndIndentPrintStream {

protected static final int BEFORE_COLUMN_ZERO = -1;
private int indent;
private PrintStream stream;
private int wrapColumn;
private PrintStream wrappedStream;

/**
* @param wrappedStream
* @param wrapColumn - first column is column 0.
* @param indent
*/
public WrapAndIndentPrintStream(PrintStream wrappedStream, int wrapColumn, int indent) {
this.wrappedStream = wrappedStream;
this.wrapColumn = wrapColumn;
this.indent = indent;
}

public PrintStream getStream() {
if (stream == null) {
stream = new PrintStream(new OutputStream() {

// Next char will go in 0
int currentColumn = BEFORE_COLUMN_ZERO;

public void write(int b) {
wrappedStream.write(b);
currentColumn = currentColumn + 1;

if (b == '\n') {
currentColumn = BEFORE_COLUMN_ZERO;
} else if (currentColumn >= wrapColumn) {
wrappedStream.write('\n');
currentColumn = BEFORE_COLUMN_ZERO;
for (int i = 0; i < indent; i++) {
if (i == 0) {
wrappedStream.write('+');
} else {
wrappedStream.write(' ');
}
currentColumn = currentColumn + 1;
}
}
}

public void close() {
wrappedStream.close();
}

public void flush() {
wrappedStream.flush();
}
});
}
return stream;
}
}
====

Hopefully this may help others.