org.apache.james.mailet.standard.mailets.UnwrapText Maven / Gradle / Ivy
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package org.apache.james.mailet.standard.mailets;
import org.apache.mailet.base.FlowedMessageUtils;
import org.apache.mailet.base.GenericMailet;
import org.apache.mailet.Mail;
import org.apache.mailet.MailetException;
import javax.mail.MessagingException;
import java.io.IOException;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
/**
* Remove (best effort to) the hardcoded wrapping from a message.
* If the text is "format=flowed" then deflows the text. Otherwise it forces a dewrap of the text.
*
* Parameters:
* quotewidth - when we try to dewrap e quoted text it helps knowing the original
* with, so we can reconstruct "wrapped wraps" created by multiple wrappings by clients with
* different original width or simply to the add of the heading ">" that increase the line
* length.
* The value should be "WIDTH+X" if the original length is known, "-X" otherwise.
* In the latter case the length of the longer line will be used.
* X is the tollerance needed for the quoting chars: if the original width is known the suggested
* value for X is 2 (because of "> " prefix), otherwise it is suggested to increase it to a value
* like 10 (-10)
*
*
* In summary, if the original wrap is known (for example 76, for flowed messages)
* quotewidth = 78
* Otherwise
* quotewidth = -10
*
*/
public class UnwrapText extends GenericMailet {
public final static String PARAMETER_NAME_QUOTEWIDTH = "quotewidth";
private int quotewidth;
/**
* returns a String describing this mailet.
*
* @return A desciption of this mailet
*/
public String getMailetInfo() {
return "UnwrapText";
}
public void init() throws MailetException {
quotewidth = Integer.parseInt(getInitParameter(PARAMETER_NAME_QUOTEWIDTH, "-10"));
}
public void service(Mail mail) throws MailetException {
try {
// TODO replace non standard quotes (at least "> " with ">", otherwise the widely used "> > >" will not work.
if (FlowedMessageUtils.isFlowedTextMessage(mail.getMessage()))
FlowedMessageUtils.deflowMessage(mail.getMessage());
else {
Object o = mail.getMessage().getContent();
if (o instanceof String) {
String unwrapped = unwrap((String) o, quotewidth);
mail.getMessage().setContent(unwrapped, mail.getMessage().getContentType());
mail.getMessage().saveChanges();
}
}
} catch (MessagingException e) {
throw new MailetException("Could not unwrap message", e);
} catch (IOException e) {
throw new MailetException("Could not unwrap message", e);
}
}
public static String unwrap(String text) {
return unwrap(text, - 10);
}
public static String unwrap(String text, int qwidth) {
String[] lines = text.split("\r\n|\n", -1);
//P1: Manage spaces without trims
Pattern p1 = Pattern.compile("([> ]*)(.*[^ .?!][ ]*)$", 0);
//P2: Quotation char at the begin of a line and the first word starts with a lowercase char or a number. The word ends with a space, a tab or a lineend.
Pattern p2 = Pattern.compile("^([> ]*)(([a-z\u00E0\u00E8\u00E9\u00EC\u00F2\u00F9][^ \t\r\n]*|[0-9][0-9,.]*)([ \t].*$|$))", 0);
// Width computation
int width = 0;
for (int i = 0; i < lines.length - 1; i++) {
String l = lines[i].trim();
if (l.length() > width) width = l.length();
}
if (width < 40) return text;
if (qwidth < 0) qwidth = width - qwidth;
StringBuilder result = new StringBuilder();
int prevWrapped = 0;
for (int i = 0; i < lines.length; i++) {
if (prevWrapped != 0) {
if (prevWrapped > 0 ) {
if (result.charAt(result.length() - 1) != ' ') result.append(" ");
}
else result.append("\r\n");
}
String l = lines[i];
Matcher m1 = p1.matcher(l);
Matcher m2 = i < lines.length - 1 ? p2.matcher(lines[i + 1]) : null;
boolean b;
int w;
// if patterns match, the quote level are identical and if the line length added to the length of the following word is greater than width then it is a wrapped line.
if (m1.matches() && i < lines.length - 1 && m2.matches() && (
// The following line has the same quoting of the previous.
((b = m1.group(1).trim().equals(m2.group(1).trim())) && l.length() + m2.group(3).length() + 1 > width)
||
// The following line has no quoting (while the previous yes)
(!b && m2.group(1).trim().equals("") && (w = l.length() + m2.group(2).trim().length() + 1) > width && w <= qwidth)
)) {
if (b) {
if (prevWrapped > 0 && m1.groupCount() >= 2) result.append(m1.group(2));
else result.append(l);
prevWrapped = 1;
} else {
lines[i + 1] = l + (l.charAt(l.length() - 1) != ' ' ? " " : "") + m2.group(2).trim();
// Revert the previous append
if (prevWrapped != 0) {
if (prevWrapped > 0) result.deleteCharAt(result.length() - 1);
else result.delete(result.length() - 2, result.length());
}
}
} else {
Matcher m3 = p2.matcher(l);
if (prevWrapped > 0 && m3.matches()) result.append(m3.group(2));
else result.append(lines[i]);
prevWrapped = -1;
}
}
return result.toString();
}
}
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