liquibase.resource

Interface Resource

All Known Implementing Classes:

AbstractResource, MockResource, PathResource, ResourceAccessor.NotFoundResource, URIResource

public interface Resource

Method Summary

Modifier and Type	Method and Description
boolean	exists()
String	getPath() Returns the normalized, ResourceAccessor-relative path for this resource.
URI	getUri() Returns a unique and complete identifier for this resource.
boolean	isWritable() Return true if the resource can be written to
InputStream	openInputStream() Opens an input stream to read from this resource.
OutputStream	openOutputStream(boolean createIfNeeded) Opens an output stream to write to this resource.
Resource	resolve(String other) Resolve the given path against this resource.
Resource	resolveSibling(String other) Resolves the given path against this resource's parent path.

Method Detail

getPath

String getPath()

Returns the normalized, ResourceAccessor-relative path for this resource. To get the unique location of this resource, use getUri() This should always use `/` for separators This should not include any sort of protocol or prefixes This should not have a leading /. This should have any relative paths smoothed out -- return "path/to/resource" not "path/from/../to/resource".

openInputStream

InputStream openInputStream()
                     throws IOException

Opens an input stream to read from this resource.

Throws:

IOException - if there is an error reading from the resource, including if the resource does not exist or cannot be read.

isWritable

boolean isWritable()

Return true if the resource can be written to

exists

boolean exists()

Returns:

true if the resource defined by this object currently exists.

resolve

Resource resolve(String other)

Resolve the given path against this resource. If other is an empty path then this method trivially returns this path. Otherwise this method considers this resource to be a directory and resolves the given path against this resource. Even if "other" begins with a `/`, the returned resource should be relative to this resource.

resolveSibling

Resource resolveSibling(String other)

Resolves the given path against this resource's parent path. This is useful where a file name needs to be replaced with another file name. For example, suppose that the name separator is "/" and a path represents "dir1/dir2/foo", then invoking this method with the Path "bar" will result in the Path "dir1/dir2/bar". If other is an empty path then this method returns this path's parent. Even if "other" begins with a `/`, the returned resource should be relative to this resource.

openOutputStream

OutputStream openOutputStream(boolean createIfNeeded)
                       throws IOException

Opens an output stream to write to this resource. Note that calling this method will truncate (erase) the existing file.

Parameters:

createIfNeeded - if true, create the resource if it does not exist. If false, throw an exception if it does not exist

Throws:

IOException - if there is an error writing to the resource, including if the resource does not exist or permission don't allow writing.

getUri

URI getUri()

Returns a unique and complete identifier for this resource. This will be different than what is returned by getPath() because the path within the resource accessor whereas this is the a complete path to it.

For example, a file resource may return a path of my/file.txt and a uri of file:/tmp/project/liquibase/my/file.txt for a resource accessor using file:/tmp/project/liquibase as a root