Package org.apache.ibatis.migration.io

Class DefaultVFS

java.lang.Object

org.apache.ibatis.migration.io.VFS

org.apache.ibatis.migration.io.DefaultVFS

public class DefaultVFS
extends VFS

A default implementation of VFS that works for most application servers.

Author:

Ben Gunter

Field Summary

Fields inherited from class org.apache.ibatis.migration.io.VFS

IMPLEMENTATIONS, USER_IMPLEMENTATIONS

Constructor Summary

Constructors

Constructor	Description
DefaultVFS()

Method Summary

Modifier and Type	Method	Description
protected URL	findJarForResource(URL url)	Attempts to deconstruct the given URL to find a JAR file containing the resource referenced by the URL.
protected String	getPackagePath(String packageName)	Converts a Java package name to a path that can be looked up with a call to ClassLoader.getResources(String).
protected boolean	isJar(URL url)	Returns true if the resource located at the given URL is a JAR file.
protected boolean	isJar(URL url, byte[] buffer)	Returns true if the resource located at the given URL is a JAR file.
boolean	isValid()	Return true if the VFS implementation is valid for the current environment.
List<String>	list(URL url, String path)	Recursively list the full resource path of all the resources that are children of the resource identified by a URL.
protected List<String>	listResources(JarInputStream jar, String path)	List the names of the entries in the given JarInputStream that begin with the specified path.

Methods inherited from class org.apache.ibatis.migration.io.VFS

addImplClass, getClass, getInstance, getMethod, getResources, invoke, list

Methods inherited from class java.lang.Object

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

Constructor Details

DefaultVFS

public DefaultVFS()

Method Details

isValid

public boolean isValid()

Description copied from class: VFS

Return true if the VFS implementation is valid for the current environment.

Specified by:

isValid in class VFS

Returns:

true, if is valid

list

public List<String> list(URL url,
 String path)
                  throws IOException

Description copied from class: VFS

Recursively list the full resource path of all the resources that are children of the resource identified by a URL.

Specified by:

list in class VFS

Parameters:

url - The URL that identifies the resource to list.

path - The path to the resource that is identified by the URL. Generally, this is the value passed to VFS.getResources(String) to get the resource URL.

Returns:

A list containing the names of the child resources.

Throws:

IOException - If I/O errors occur

listResources

protected List<String> listResources(JarInputStream jar,
 String path)
                              throws IOException

List the names of the entries in the given JarInputStream that begin with the specified path. Entries will match with or without a leading slash.

Parameters:

jar - The JAR input stream

path - The leading path to match

Returns:

The names of all the matching entries

Throws:

IOException - If I/O errors occur

findJarForResource

protected URL findJarForResource(URL url)
                          throws MalformedURLException

Attempts to deconstruct the given URL to find a JAR file containing the resource referenced by the URL. That is, assuming the URL references a JAR entry, this method will return a URL that references the JAR file containing the entry. If the JAR cannot be located, then this method returns null.

Parameters:

url - The URL of the JAR entry.

Returns:

The URL of the JAR file, if one is found. Null if not.

Throws:

MalformedURLException - the malformed URL exception

getPackagePath

protected String getPackagePath(String packageName)

Converts a Java package name to a path that can be looked up with a call to ClassLoader.getResources(String).

Parameters:

packageName - The Java package name to convert to a path

Returns:

the package path

isJar

protected boolean isJar(URL url)

Returns true if the resource located at the given URL is a JAR file.

Parameters:

url - The URL of the resource to test.

Returns:

true, if is jar

isJar

protected boolean isJar(URL url,
 byte[] buffer)

Returns true if the resource located at the given URL is a JAR file.

Parameters:

url - The URL of the resource to test.

buffer - A buffer into which the first few bytes of the resource are read. The buffer must be at least the size of JAR_MAGIC. (The same buffer may be reused for multiple calls as an optimization.)

Returns:

true, if is jar