com.ds.common.logging.impl

类 LogFactoryImpl

java.lang.Object

com.ds.common.logging.LogFactory

com.ds.common.logging.impl.LogFactoryImpl

public class LogFactoryImpl
extends LogFactory

Title: 常用代码打包

Description: Concrete subclass of LogFactory that implements the following algorithm to dynamically select a logging implementation class to instantiate a wrapper for.

• Use a factory configuration attribute named org.apache.commons.logging.Log to identify the requested implementation class.
• Use the org.apache.commons.logging.Log system property to identify the requested implementation class.
• If Log4J is available, return an instance of org.apache.commons.logging.impl.Log4JLogger.
• If JDK 1.4 or later is available, return an instance of org.apache.commons.logging.impl.Jdk14Logger.
• Otherwise, return an instance of org.apache.commons.logging.impl.SimpleLog.

If the selected Log implementation class has a setLogFactory() method that accepts a LogFactory parameter, this method will be called on each newly created instance to identify the associated factory. This makes factory configuration attributes available to the Log instance, if it so desires.

This factory will remember previously created Log instances for the same name, and will return them on repeated requests to the getInstance() method. This implementation ignores any configured attributes.

Copyright: Copyright (c) 2006

Company: www.justdos.net

版本:

1.0

作者:

wenzhang li

字段概要

字段

限定符和类型	字段和说明
protected Hashtable	instances The Log instances that have already been created, keyed by logger name.
protected Constructor	logConstructor The one-argument constructor of the Log implementation class that will be used to create new instances.
protected Class[]	logConstructorSignature The signature of the Constructor to be used.
protected Method	logMethod The one-argument setLogFactory method of the selected Log method, if it exists.
protected Class[]	logMethodSignature The signature of the setLogFactory method to be used.

从类继承的字段 com.ds.common.logging.LogFactory

configKey, factories, FACTORY_DEFAULT

构造器概要

构造器

构造器和说明
LogFactoryImpl() Public no-arguments constructor required by the lookup mechanism.

方法概要

限定符和类型	方法和说明
Log	getInstance(Class clazz) Convenience method to derive a name from the specified class and call getInstance(String) with it.
Log	getInstance(String name) Construct (if necessary) and return a Log instance, using the factory's current set of configuration attributes.
protected String	getLogClassName() Return the fully qualified Java classname of the Log implementation we will be using.
protected Constructor	getLogConstructor() Return the Constructor that can be called to instantiate new Log instances.
protected boolean	isJdk14Available() Is JDK 1.4 or later logging available?
protected boolean	isLog4JAvailable() Is a Log4J implementation available?
protected Log	newInstance(String name) Create and return a new Log instance for the specified name.
void	release() Release any internal references to previously created Log instances returned by this factory.

从类继承的方法 com.ds.common.logging.LogFactory

getContextClassLoader, getFactory, getLog, getLog, newFactory, release, releaseAll

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

字段详细资料

instances

protected Hashtable instances

The Log instances that have already been created, keyed by logger name.

logConstructor

protected Constructor logConstructor

The one-argument constructor of the Log implementation class that will be used to create new instances. This value is initialized by getLogConstructor(), and then returned repeatedly.

logConstructorSignature

protected Class[] logConstructorSignature

The signature of the Constructor to be used.

logMethod

protected Method logMethod

The one-argument setLogFactory method of the selected Log method, if it exists.

logMethodSignature

protected Class[] logMethodSignature

The signature of the setLogFactory method to be used.

构造器详细资料

LogFactoryImpl

public LogFactoryImpl()

Public no-arguments constructor required by the lookup mechanism.

方法详细资料

getInstance

public Log getInstance(Class clazz)
                throws LogConfigurationException

Convenience method to derive a name from the specified class and call getInstance(String) with it.

指定者:

getInstance 在类中 LogFactory

参数:

clazz - Class for which a suitable Log name will be derived

抛出:

LogConfigurationException - if a suitable Log instance cannot be returned

getInstance

public Log getInstance(String name)
                throws LogConfigurationException

Construct (if necessary) and return a Log instance, using the factory's current set of configuration attributes.

NOTE - Depending upon the implementation of the LogFactory you are using, the Log instance you are returned may or may not be local to the current application, and may or may not be returned again on a subsequent call with the same name argument.

指定者:

getInstance 在类中 LogFactory

参数:

name - Logical name of the Log instance to be returned (the meaning of this name is only known to the underlying logging implementation that is being wrapped)

抛出:

LogConfigurationException - if a suitable Log instance cannot be returned

release

public void release()

Release any internal references to previously created Log instances returned by this factory. This is useful environments like servlet containers, which implement application reloading by throwing away a ClassLoader. Dangling references to objects in that class loader would prevent garbage collection.

指定者:

release 在类中 LogFactory

getLogClassName

protected String getLogClassName()

Return the fully qualified Java classname of the Log implementation we will be using.

getLogConstructor

protected Constructor getLogConstructor()
                                 throws LogConfigurationException

Return the Constructor that can be called to instantiate new Log instances.

IMPLEMENTATION NOTE - Race conditions caused by calling this method from more than one thread are ignored, because the same Constructor instance will ultimately be derived in all circumstances.

抛出:

LogConfigurationException - if a suitable constructor cannot be returned

isJdk14Available

protected boolean isJdk14Available()

Is JDK 1.4 or later logging available?

isLog4JAvailable

protected boolean isLog4JAvailable()

Is a Log4J implementation available?

newInstance

protected Log newInstance(String name)
                   throws LogConfigurationException

Create and return a new Log instance for the specified name.

参数:

name - Name of the new logger

抛出:

LogConfigurationException - if a new instance cannot be created