On Tue, Oct 9, 2012 at 10:19 AM, Ralph Goers <[email protected]>wrote:
> This requires a long answer.
>
> Ceki realized in Logback that OutputStreams really needed a byte array.
> So he changed Appenders to require an Encoder instead of an Appender.
> Layouts still return a String so he created a wrapper Encoder to convert
> the String to a byte array.
>
> The idea of using a byte array is correct - most of the time, as most of
> the Appenders use an OutputStream. However, the JMS appenders don't. They
> require a Serializable object.
>
> When developing Log4j I did not like having both Encoders and Layouts, so
> I chose to have Layouts return a byte array. But then it made no sense to
> have something based on the AbstractStringLayout convert the String to a
> byte array only to have to convert it back to a String again for the JMS
> Appenders, which is why I added formatAs(). Now the JMS Appender can send
> both a Serialized LogEvent and a String.
>
> So in looking at how formatAs() is used I would think that we could just
> change Layout to
>
> public interface Layout {
>
> Serializable formatAs();
>
> ...
> }
>
> I tried that refactoring and ran into one ugly:
>
For
org.apache.logging.log4j.core.layout.AbstractStringLayout.format(LogEvent)
I had to change:
public byte[] format(LogEvent event) {
return encoder.getBytes(*formatAs(event)*);
}
to:
public byte[] format(LogEvent event) {
return encoder.getBytes(*formatAs(event).toString()*);
}
The change set is below.
Thoughts?
Gary
Index:
src/main/java/org/apache/logging/log4j/core/layout/AbstractLayout.java
===================================================================
---
src/main/java/org/apache/logging/log4j/core/layout/AbstractLayout.java
(revision 1396432)
+++
src/main/java/org/apache/logging/log4j/core/layout/AbstractLayout.java
(working copy)
@@ -20,13 +20,10 @@
import org.apache.logging.log4j.core.Layout;
import org.apache.logging.log4j.status.StatusLogger;
-import java.io.Serializable;
-
/**
* Base class for Layouts.
- * @param <T> The Class that the Layout will format the LogEvent into.
*/
-public abstract class AbstractLayout<T extends Serializable> implements
Layout<T> {
+public abstract class AbstractLayout implements Layout {
/**
* Allow subclasses access to the status logger without creating
another instance.
*/
Index:
src/main/java/org/apache/logging/log4j/core/layout/AbstractStringLayout.java
===================================================================
---
src/main/java/org/apache/logging/log4j/core/layout/AbstractStringLayout.java
(revision 1396432)
+++
src/main/java/org/apache/logging/log4j/core/layout/AbstractStringLayout.java
(working copy)
@@ -24,7 +24,7 @@
/**
* Base class for Layouts that result in a String.
*/
-public abstract class AbstractStringLayout extends AbstractLayout<String> {
+public abstract class AbstractStringLayout extends AbstractLayout {
/**
* The charset of the formatted message.
@@ -54,7 +54,7 @@
* @return The formatted event as a byte array.
*/
public byte[] format(LogEvent event) {
- return encoder.getBytes(formatAs(event));
+ return encoder.getBytes(formatAs(event).toString());
}
protected Charset getCharset() {
Index: src/main/java/org/apache/logging/log4j/core/layout/HTMLLayout.java
===================================================================
--- src/main/java/org/apache/logging/log4j/core/layout/HTMLLayout.java
(revision 1396432)
+++ src/main/java/org/apache/logging/log4j/core/layout/HTMLLayout.java
(working copy)
@@ -27,6 +27,7 @@
import java.io.InterruptedIOException;
import java.io.LineNumberReader;
import java.io.PrintWriter;
+import java.io.Serializable;
import java.io.StringReader;
import java.io.StringWriter;
import java.lang.management.ManagementFactory;
@@ -73,7 +74,7 @@
* @param event The Logging Event.
* @return A String containging the LogEvent as HTML.
*/
- public String formatAs(LogEvent event) {
+ public Serializable formatAs(LogEvent event) {
StringBuilder sbuf = new StringBuilder(BUF_SIZE);
sbuf.append(LINE_SEP).append("<tr>").append(LINE_SEP);
Index: src/main/java/org/apache/logging/log4j/core/layout/PatternLayout.java
===================================================================
---
src/main/java/org/apache/logging/log4j/core/layout/PatternLayout.java
(revision 1396432)
+++
src/main/java/org/apache/logging/log4j/core/layout/PatternLayout.java
(working copy)
@@ -29,6 +29,7 @@
import org.apache.logging.log4j.core.pattern.PatternParser;
import org.apache.logging.log4j.core.pattern.RegexReplacement;
+import java.io.Serializable;
import java.nio.charset.Charset;
import java.util.List;
@@ -134,7 +135,7 @@
* @param event logging event to be formatted.
* @return The event formatted as a String.
*/
- public String formatAs(final LogEvent event) {
+ public Serializable formatAs(final LogEvent event) {
StringBuilder buf = new StringBuilder();
for (PatternFormatter formatter : formatters) {
formatter.format(event, buf);
Index: src/main/java/org/apache/logging/log4j/core/layout/RFC5424Layout.java
===================================================================
---
src/main/java/org/apache/logging/log4j/core/layout/RFC5424Layout.java
(revision 1396432)
+++
src/main/java/org/apache/logging/log4j/core/layout/RFC5424Layout.java
(working copy)
@@ -29,6 +29,7 @@
import org.apache.logging.log4j.message.StructuredDataId;
import org.apache.logging.log4j.message.StructuredDataMessage;
+import java.io.Serializable;
import java.net.InetAddress;
import java.net.NetworkInterface;
import java.net.SocketException;
@@ -151,7 +152,7 @@
* @param event The LogEvent.
* @return The RFC 5424 String representation of the LogEvent.
*/
- public String formatAs(final LogEvent event) {
+ public Serializable formatAs(final LogEvent event) {
Message msg = event.getMessage();
boolean isStructured = msg instanceof StructuredDataMessage;
StringBuilder buf = new StringBuilder();
Index:
src/main/java/org/apache/logging/log4j/core/layout/SerializedLayout.java
===================================================================
---
src/main/java/org/apache/logging/log4j/core/layout/SerializedLayout.java
(revision 1396432)
+++
src/main/java/org/apache/logging/log4j/core/layout/SerializedLayout.java
(working copy)
@@ -24,12 +24,13 @@
import java.io.IOException;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
+import java.io.Serializable;
/**
* Format a LogEvent in its serialized form.
*/
@Plugin(name = "SerializedLayout", type = "Core", elementType = "layout",
printObject = true)
-public final class SerializedLayout extends AbstractLayout<LogEvent> {
+public final class SerializedLayout extends AbstractLayout {
private static byte[] header;
@@ -68,7 +69,7 @@
* @param event The Logging Event.
* @return The LogEvent.
*/
- public LogEvent formatAs(final LogEvent event) {
+ public Serializable formatAs(final LogEvent event) {
return event;
}
Index: src/main/java/org/apache/logging/log4j/core/layout/SyslogLayout.java
===================================================================
--- src/main/java/org/apache/logging/log4j/core/layout/SyslogLayout.java
(revision 1396432)
+++ src/main/java/org/apache/logging/log4j/core/layout/SyslogLayout.java
(working copy)
@@ -23,6 +23,7 @@
import org.apache.logging.log4j.core.net.Facility;
import org.apache.logging.log4j.core.net.Priority;
+import java.io.Serializable;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.nio.charset.Charset;
@@ -61,7 +62,7 @@
* @param event The LogEvent
* @return the event formatted as a String.
*/
- public String formatAs(final LogEvent event) {
+ public Serializable formatAs(final LogEvent event) {
StringBuilder buf = new StringBuilder();
buf.append("<");
Index: src/main/java/org/apache/logging/log4j/core/layout/XMLLayout.java
===================================================================
--- src/main/java/org/apache/logging/log4j/core/layout/XMLLayout.java
(revision 1396432)
+++ src/main/java/org/apache/logging/log4j/core/layout/XMLLayout.java
(working copy)
@@ -20,6 +20,7 @@
import java.io.InterruptedIOException;
import java.io.LineNumberReader;
import java.io.PrintWriter;
+import java.io.Serializable;
import java.io.StringReader;
import java.io.StringWriter;
import java.nio.charset.Charset;
@@ -93,7 +94,7 @@
* @param event The LogEvent.
* @return The XML representation of the LogEvent.
*/
- public String formatAs(final LogEvent event) {
+ public Serializable formatAs(final LogEvent event) {
StringBuilder buf = new StringBuilder(DEFAULT_SIZE);
// We yield to the \r\n heresy.
Index: src/main/java/org/apache/logging/log4j/core/Layout.java
===================================================================
--- src/main/java/org/apache/logging/log4j/core/Layout.java (revision
1396432)
+++ src/main/java/org/apache/logging/log4j/core/Layout.java (working
copy)
@@ -23,9 +23,8 @@
* Would introduce an EventEncoder, EventRenderer or something similar
for the logging event to byte encoding.
* (RG) A layout can be configured with a Charset and then Strings can be
converted to byte arrays. OTOH, it isn't
* possible to write byte arrays as character streams.
- * @param <T> The Object type that will be returned on the formatAs call.
*/
-public interface Layout<T extends Serializable> {
+public interface Layout {
/**
* Formats the event suitable for display.
* @param event The Logging Event.
@@ -41,7 +40,7 @@
* @param event The Logging Event.
* @return The formatted event.
*/
- T formatAs(LogEvent event);
+ Serializable formatAs(LogEvent event);
/**
* Returns the header for the layout format.
Gary
> On Oct 9, 2012, at 6:23 AM, Gary Gregory wrote:
>
> Hi All:
>
> We currently have a generics warning for:
>
> org.apache.logging.log4j.core.Appender.getLayout()
>
> because the method is defined as:
>
> Layout getLayout();
>
> and Layout<T extends Serializable>
>
> Which hints at defining getLayout() as:
>
> Layout<T> getLayout();
>
> Which means either:
>
> <T extends Serializable> Layout<T> getLayout();
>
> or:
>
> public interface Appender<T extends Serializable> extends Lifecycle {
> ...
> Layout<T> getLayout();
>
> Now I also see:
>
> @issue LOG4J2-36 Refactor into Channel
>
> But the issue has been closed with no changes planned.
>
> So... thoughts?
>
> Gary
>
>
>
>
> --
> E-Mail: [email protected] | [email protected]
> JUnit in Action, 2nd Ed: <http://goog_1249600977/>http://bit.ly/ECvg0
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> Blog: http://garygregory.wordpress.com
> Home: http://garygregory.com/
> Tweet! http://twitter.com/GaryGregory
>
>
>
--
E-Mail: [email protected] | [email protected]
JUnit in Action, 2nd Ed: <http://goog_1249600977>http://bit.ly/ECvg0
Spring Batch in Action: <http://s.apache.org/HOq>http://bit.ly/bqpbCK
Blog: http://garygregory.wordpress.com
Home: http://garygregory.com/
Tweet! http://twitter.com/GaryGregory
