import java.lang.ref.SoftReference;
import java.text.DateFormat;
import java.text.FieldPosition;
import java.text.ParsePosition;
import java.text.SimpleDateFormat;
import java.util.Date;
/**
* Thread-safe version of java.text.DateFormat.
* You can declare it as a static final variable:
*
* private static final ThreadSafeDateFormat
* DATE_FORMAT = new ThreadSafeDateFormat( DATE_PATTERN );
*/
public class ThreadSafeDateFormat extends DateFormat
{
private static final long serialVersionUID = 3786090697869963812L;
private final String m_sDateFormat;
public ThreadSafeDateFormat(String sDateFormat)
{
m_sDateFormat = sDateFormat;
}
private final ThreadLocal m_formatCache = new ThreadLocal()
{
public Object get()
{
SoftReference softRef = (SoftReference) super.get();
if (softRef == null || softRef.get() == null)
{
softRef = new SoftReference(
new SimpleDateFormat(m_sDateFormat) );
super.set(softRef);
}
return softRef;
}
};
private DateFormat getDateFormat()
{
return (DateFormat) (
(SoftReference)m_formatCache.get()).get();
}
public StringBuffer format(Date date,
StringBuffer toAppendTo, FieldPosition fieldPosition)
{
return getDateFormat().format(
date, toAppendTo, fieldPosition);
}
public Date parse(String source, ParsePosition pos)
{
return getDateFormat().parse(source, pos);
}
}
<pluginManagement>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-scm-plugin</artifactId>
<version>1.1.INTERNAL-SNAPSHOT</version>
</plugin>
</plugins>
</pluginManagement>
/**
* Method returns code source of given class.
* This is URL of classpath folder, zip or jar file.
* If code source is unknown, returns null (for example, for classes java.io.*).
*
* @param clazz For example,java.sql.SQLException.class
* @return for example,"file:/C:/jdev10/jdev/mywork/classes/"
* or"file:/C:/works/projects/classes12.zip"
*/
public static String getCodeSource(Class clazz)
{
if (clazz == null ||
clazz.getProtectionDomain() == null ||
clazz.getProtectionDomain().getCodeSource() == null ||
clazz.getProtectionDomain().getCodeSource().getLocation() == null)
// This typically happens for system classloader
// (java.lang.* etc. classes)
return null;
return clazz.getProtectionDomain()
.getCodeSource().getLocation().toString();
}
,
<project>
<scm>
<connection>scm:proxyscm:cvs:pserver:@myhost:dir:nodule</connection>
<developerConnection>scm:proxyscm:cvs:pserver:bla-bla</developerConnection>
</scm>
<modules>
<module path="robots/terminator/sdk">terminator_sdk</module>
<module path="robots/terminator/ui" tag="terminator_ui_v1-2">terminator_ui</module>
<module scmProvider="svn" scmHost="http://svn.apache.org/repos/asf/commons/proper/launcher" path="trunk">commons_launcher</module>
</modules>
</project>
In many languages (C++), uninitialized variables lead to errors. So, it's considered to be a good style to initialize every variable with 0 or null.
however, in Java it's quite the opposite.
Initialization with null is not recommended for those class members that should not be null.
Instead, it's recommended to declare those members final and initialize only once with an adequate value.
See example below.
private CCollectorTarget m_collectTrg = null;
private CCollectorSchema m_collectSchm = null;
private CCollectorProject m_collectPrj = null;
private CCollectorFiles m_collectFiles = null;
public CCollectorData( CCollectorTarget collectTrg,
CCollectorSchema collectSchm,
CCollectorProject collectPrj,
CCollectorFiles collectFiles )
{
m_collectSchm = collectSchm;
m_collectTrg = collectTrg;
m_collectPrj = collectPrj;
m_collectFiles = collectFiles;
}
private final CCollectorTarget m_collectTrg;
private final CCollectorSchema m_collectSchm;
private final CCollectorProject m_collectPrj;
private final CCollectorFiles m_collectFiles;
public CCollectorData( CCollectorTarget collectTrg,
CCollectorSchema collectSchm,
CCollectorProject collectPrj,
CCollectorFiles collectFiles )
{
m_collectSchm = collectSchm;
m_collectTrg = collectTrg;
m_collectPrj = collectPrj;
m_collectFiles = collectFiles;
}
This technique has additional advantages: java compiler detects cases when you
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