How do I get java logging output to appear on a single line?
JavaLoggingJava Problem Overview
At the moment a default entry looks something like this:
Oct 12, 2008 9:45:18 AM myClassInfoHere
INFO: MyLogMessageHere
How do I get it to do this?
Oct 12, 2008 9:45:18 AM myClassInfoHere - INFO: MyLogMessageHere
Clarification I'm using java.util.logging
Java Solutions
Solution 1 - Java
As of Java 7, java.util.logging.SimpleFormatter supports getting its format from a system property, so adding something like this to the JVM command line will cause it to print on one line:
-Djava.util.logging.SimpleFormatter.format='%1$tY-%1$tm-%1$td %1$tH:%1$tM:%1$tS %4$s %2$s %5$s%6$s%n'
Alternatively, you can also add this to your logger.properties
:
java.util.logging.SimpleFormatter.format='%1$tY-%1$tm-%1$td %1$tH:%1$tM:%1$tS %4$s %2$s %5$s%6$s%n'
Solution 2 - Java
-Djava.util.logging.SimpleFormatter.format
1) Java 7 supports a property with the java.util.Formatter
format string syntax.
-Djava.util.logging.SimpleFormatter.format=...
See here.
My favorite is:
-Djava.util.logging.SimpleFormatter.format=%1$tY-%1$tm-%1$td %1$tH:%1$tM:%1$tS %4$-6s %2$s %5$s%6$s%n
which makes output like:
2014-09-02 16:44:57 SEVERE org.jboss.windup.util.ZipUtil unzip: Failed to load: foo.zip
2) Putting it to IDEs
IDEs typically let you set system properties for a project.
E.g. in NetBeans, instead of adding -D...=... somewhere, add the property in the action dialog, in a form of java.util.logging.SimpleFormatter.format=%1$tY-%1$tm-...
- without any quotes. The IDE should figure out.
3) Putting that to Maven - Surefire
For your convenience, Here is how to put it to Surefire:
<!-- Surefire -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.17</version>
<configuration>
<systemPropertyVariables>
<!-- Set JUL Formatting -->
<java.util.logging.SimpleFormatter.format>%1$tY-%1$tm-%1$td %1$tH:%1$tM:%1$tS %4$-6s %2$s %5$s%6$s%n</java.util.logging.SimpleFormatter.format>
</systemPropertyVariables>
</configuration>
</plugin>
4) Hand-made
I have a library with few java.util.logging
related classes. Amongst them, it's SingleLineFormatter
.
Downloadable jar here.
public class SingleLineFormatter extends Formatter {
Date dat = new Date();
private final static String format = "{0,date} {0,time}";
private MessageFormat formatter;
private Object args[] = new Object[1];
// Line separator string. This is the value of the line.separator
// property at the moment that the SimpleFormatter was created.
//private String lineSeparator = (String) java.security.AccessController.doPrivileged(
// new sun.security.action.GetPropertyAction("line.separator"));
private String lineSeparator = "\n";
/**
* Format the given LogRecord.
* @param record the log record to be formatted.
* @return a formatted log record
*/
public synchronized String format(LogRecord record) {
StringBuilder sb = new StringBuilder();
// Minimize memory allocations here.
dat.setTime(record.getMillis());
args[0] = dat;
// Date and time
StringBuffer text = new StringBuffer();
if (formatter == null) {
formatter = new MessageFormat(format);
}
formatter.format(args, text, null);
sb.append(text);
sb.append(" ");
// Class name
if (record.getSourceClassName() != null) {
sb.append(record.getSourceClassName());
} else {
sb.append(record.getLoggerName());
}
// Method name
if (record.getSourceMethodName() != null) {
sb.append(" ");
sb.append(record.getSourceMethodName());
}
sb.append(" - "); // lineSeparator
String message = formatMessage(record);
// Level
sb.append(record.getLevel().getLocalizedName());
sb.append(": ");
// Indent - the more serious, the more indented.
//sb.append( String.format("% ""s") );
int iOffset = (1000 - record.getLevel().intValue()) / 100;
for( int i = 0; i < iOffset; i++ ){
sb.append(" ");
}
sb.append(message);
sb.append(lineSeparator);
if (record.getThrown() != null) {
try {
StringWriter sw = new StringWriter();
PrintWriter pw = new PrintWriter(sw);
record.getThrown().printStackTrace(pw);
pw.close();
sb.append(sw.toString());
} catch (Exception ex) {
}
}
return sb.toString();
}
}
Solution 3 - Java
Similar to Tervor, But I like to change the property on runtime.
Note that this need to be set before the first SimpleFormatter is created - as was written in the comments.
System.setProperty("java.util.logging.SimpleFormatter.format",
"%1$tF %1$tT %4$s %2$s %5$s%6$s%n");
Solution 4 - Java
Like Obediah Stane said, it's necessary to create your own format
method. But I would change a few things:
-
Create a subclass directly derived from
Formatter
, not fromSimpleFormatter
. TheSimpleFormatter
has nothing to add anymore. -
Be careful with creating a new
Date
object! You should make sure to represent the date of theLogRecord
. When creating a newDate
with the default constructor, it will represent the date and time theFormatter
processes theLogRecord
, not the date that theLogRecord
was created.
The following class can be used as formatter in a Handler
, which in turn can be added to the Logger
. Note that it ignores all class and method information available in the LogRecord
.
import java.io.PrintWriter;
import java.io.StringWriter;
import java.util.Date;
import java.util.logging.Formatter;
import java.util.logging.LogRecord;
public final class LogFormatter extends Formatter {
private static final String LINE_SEPARATOR = System.getProperty("line.separator");
@Override
public String format(LogRecord record) {
StringBuilder sb = new StringBuilder();
sb.append(new Date(record.getMillis()))
.append(" ")
.append(record.getLevel().getLocalizedName())
.append(": ")
.append(formatMessage(record))
.append(LINE_SEPARATOR);
if (record.getThrown() != null) {
try {
StringWriter sw = new StringWriter();
PrintWriter pw = new PrintWriter(sw);
record.getThrown().printStackTrace(pw);
pw.close();
sb.append(sw.toString());
} catch (Exception ex) {
// ignore
}
}
return sb.toString();
}
}
Solution 5 - Java
This is what I'm using.
public class VerySimpleFormatter extends Formatter {
private static final String PATTERN = "yyyy-MM-dd'T'HH:mm:ss.SSSXXX";
@Override
public String format(final LogRecord record) {
return String.format(
"%1$s %2$-7s %3$s\n",
new SimpleDateFormat(PATTERN).format(
new Date(record.getMillis())),
record.getLevel().getName(), formatMessage(record));
}
}
You'll get something like...
2016-08-19T17:43:14.295+09:00 INFO Hey~
2016-08-19T17:43:16.068+09:00 SEVERE Seriously?
2016-08-19T17:43:16.068+09:00 WARNING I'm warning you!!!
Solution 6 - Java
Per screenshot, in Eclipse select "run as" then "Run Configurations..." and add the answer from Trevor Robinson with double quotes instead of quotes. If you miss the double quotes you'll get "could not find or load main class" errors.
Solution 7 - Java
I've figured out a way that works. You can subclass SimpleFormatter and override the format method
public String format(LogRecord record) {
return new java.util.Date() + " " + record.getLevel() + " " + record.getMessage() + "\r\n";
}
A bit surprised at this API I would have thought that more functionality/flexibility would have been provided out of the box
Solution 8 - Java
If you log in a web application using tomcat add:
-Djava.util.logging.ConsoleHandler.formatter = org.apache.juli.OneLineFormatter
On VM arguments
Solution 9 - Java
This logging is specific to your application and not a general Java feature. What application(s) are you running?
It might be that this is coming from a specific logging library that you are using within your own code. If so, please post the details of which one you are using.
Solution 10 - Java
if you're using java.util.logging, then there is a configuration file that is doing this to log contents (unless you're using programmatic configuration). So, your options are
- run post -processor that removes the line breaks
- change the log configuration AND remove the line breaks from it. Restart your application (server) and you should be good.