Package net.sf.jasperreports.engine.util

Class JRLoader

java.lang.Object

net.sf.jasperreports.engine.util.JRLoader

public final class JRLoader
extends Object

Utility class that helps load serialized objects found in various locations such as files, URLs, and input streams.

Many JasperReports processes, like report compilation, report filling and exporting, often work with serialized objects. Sometimes it is useful to manually load those serialized objects before submitting them to the desired JasperReport process.

The most interesting method exposed by this class is getLocationInputStream(String location). When calling this method to load an InputStream object from the supplied location, the program first tries to interpret the location as a valid resource name. If this fails, then the program assumes that the supplied location is the name of a file on disk and tries to read from it. If no file is found at that location, it will assume that the location represents a valid URL. Only after this third try fails an exception is thrown.

Author:

Teodor Danciu (teodord@users.sourceforge.net)

Field Summary

Fields

Modifier and Type	Field	Description
static final String	EXCEPTION_MESSAGE_KEY_BYTE_DATA_FROM_INPUT_STREAM_ERROR
static final String	EXCEPTION_MESSAGE_KEY_BYTE_DATA_LOADING_ERROR
static final String	EXCEPTION_MESSAGE_KEY_CLASS_NOT_FOUND_FROM_FILE
static final String	EXCEPTION_MESSAGE_KEY_CLASS_NOT_FOUND_FROM_INPUT_STREAM
static final String	EXCEPTION_MESSAGE_KEY_CLASS_NOT_FOUND_FROM_URL
static final String	EXCEPTION_MESSAGE_KEY_FILE_OPEN_ERROR
static final String	EXCEPTION_MESSAGE_KEY_INPUT_STREAM_FROM_FILE_OPEN_ERROR
static final String	EXCEPTION_MESSAGE_KEY_INPUT_STREAM_FROM_URL_OPEN_ERROR
static final String	EXCEPTION_MESSAGE_KEY_OBJECT_FROM_FILE_LOADING_ERROR
static final String	EXCEPTION_MESSAGE_KEY_OBJECT_FROM_INPUT_STREAM_LOADING_ERROR
static final String	EXCEPTION_MESSAGE_KEY_OBJECT_FROM_URL_LOADING_ERROR
static final String	EXCEPTION_MESSAGE_KEY_RESOURCE_NOT_FOUND
static final String	EXCEPTION_MESSAGE_KEY_URL_OPEN_ERROR

Method Summary

Modifier and Type	Method	Description
protected static void	collectResources(String resourceName, ClassLoader classLoader, Map<URL,ClassLoaderResource> resources)
protected static void	collectResources(String resourceName, ClassLoader classLoader, Set<URL> resources)
static List<ClassLoaderResource>	getClassLoaderResources(String resource)	Scans the context classloader and the classloader of this class for all resources that have a specified name, and returns a list of ClassLoaderResource objects for the found resources.
static InputStream	getFileInputStream(String filename)	Tries to open a file for reading.
static InputStream	getInputStream(File file)
static InputStream	getInputStream(URL url)
static InputStream	getLocationInputStream(String location)	Tries to open an input stream for a location.
static URL	getResource(String resource)	Returns the resource URL for a specified resource name.
static InputStream	getResourceInputStream(String resource)	Tries to open an input stream for a resource.
static List<URL>	getResources(String resource)	Scans the context classloader and the classloader of this class for all resources that have a specified name, and returns a list of URLs for the found resources.
static InputStream	getURLInputStream(String spec)	Tries to open an input stream for an URL.
static byte[]	loadBytes(File file)
static byte[]	loadBytes(InputStream is)
static byte[]	loadBytes(URL url)
static byte[]	loadBytesFromResource(String resourceName)
static byte[]	loadBytesFromResource(String resourceName, ClassLoader classLoader)
static JasperPrint	loadJasperPrint(File file, JRVirtualizer virtualizer)	Loads a JasperPrint object from a file, optionally using a virtualizer for the object.
static JasperPrint	loadJasperPrint(InputStream is, JRVirtualizer virtualizer)	Loads a JasperPrint object from a stream, optionally using a virtualizer for the object.
static JasperPrint	loadJasperPrint(URL url, JRVirtualizer virtualizer)	Loads a JasperPrint object from a URL, optionally using a virtualizer for the object.
static JasperPrint	loadJasperPrintFromFile(String fileName, JRVirtualizer virtualizer)	Loads a JasperPrint object from a file, optionally using a virtualizer for the object.
static Object	loadObject(File file)
static Object	loadObject(InputStream is)
static Object	loadObject(URL url)
static Object	loadObject(JasperReportsContext jasperReportsContext, File file)
static Object	loadObject(JasperReportsContext jasperReportsContext, InputStream is)
static Object	loadObject(JasperReportsContext jasperReportsContext, URL url)
static Object	loadObjectFromFile(String fileName)
static byte[]	readBytes(InputStream is)

Methods inherited from class java.lang.Object

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

Field Details

EXCEPTION_MESSAGE_KEY_BYTE_DATA_FROM_INPUT_STREAM_ERROR

public static final String EXCEPTION_MESSAGE_KEY_BYTE_DATA_FROM_INPUT_STREAM_ERROR

See Also:

• Constant Field Values

EXCEPTION_MESSAGE_KEY_BYTE_DATA_LOADING_ERROR

public static final String EXCEPTION_MESSAGE_KEY_BYTE_DATA_LOADING_ERROR

See Also:

• Constant Field Values

EXCEPTION_MESSAGE_KEY_CLASS_NOT_FOUND_FROM_FILE

public static final String EXCEPTION_MESSAGE_KEY_CLASS_NOT_FOUND_FROM_FILE

See Also:

• Constant Field Values

EXCEPTION_MESSAGE_KEY_CLASS_NOT_FOUND_FROM_INPUT_STREAM

public static final String EXCEPTION_MESSAGE_KEY_CLASS_NOT_FOUND_FROM_INPUT_STREAM

See Also:

• Constant Field Values

EXCEPTION_MESSAGE_KEY_CLASS_NOT_FOUND_FROM_URL

public static final String EXCEPTION_MESSAGE_KEY_CLASS_NOT_FOUND_FROM_URL

See Also:

• Constant Field Values

EXCEPTION_MESSAGE_KEY_FILE_OPEN_ERROR

public static final String EXCEPTION_MESSAGE_KEY_FILE_OPEN_ERROR

See Also:

• Constant Field Values

EXCEPTION_MESSAGE_KEY_INPUT_STREAM_FROM_FILE_OPEN_ERROR

public static final String EXCEPTION_MESSAGE_KEY_INPUT_STREAM_FROM_FILE_OPEN_ERROR

See Also:

• Constant Field Values

EXCEPTION_MESSAGE_KEY_INPUT_STREAM_FROM_URL_OPEN_ERROR

public static final String EXCEPTION_MESSAGE_KEY_INPUT_STREAM_FROM_URL_OPEN_ERROR

See Also:

• Constant Field Values

EXCEPTION_MESSAGE_KEY_OBJECT_FROM_FILE_LOADING_ERROR

public static final String EXCEPTION_MESSAGE_KEY_OBJECT_FROM_FILE_LOADING_ERROR

See Also:

• Constant Field Values

EXCEPTION_MESSAGE_KEY_OBJECT_FROM_INPUT_STREAM_LOADING_ERROR

public static final String EXCEPTION_MESSAGE_KEY_OBJECT_FROM_INPUT_STREAM_LOADING_ERROR

See Also:

• Constant Field Values

EXCEPTION_MESSAGE_KEY_OBJECT_FROM_URL_LOADING_ERROR

public static final String EXCEPTION_MESSAGE_KEY_OBJECT_FROM_URL_LOADING_ERROR

See Also:

• Constant Field Values

EXCEPTION_MESSAGE_KEY_RESOURCE_NOT_FOUND

public static final String EXCEPTION_MESSAGE_KEY_RESOURCE_NOT_FOUND

See Also:

• Constant Field Values

EXCEPTION_MESSAGE_KEY_URL_OPEN_ERROR

public static final String EXCEPTION_MESSAGE_KEY_URL_OPEN_ERROR

See Also:

• Constant Field Values

Method Details

loadObjectFromFile

public static Object loadObjectFromFile(String fileName)
                                 throws JRException

Throws:

JRException

loadObject

public static Object loadObject(File file)
                         throws JRException

Throws:

JRException

loadObject

public static Object loadObject(JasperReportsContext jasperReportsContext,
 File file)
                         throws JRException

Throws:

JRException

loadObject

public static Object loadObject(URL url)
                         throws JRException

Throws:

JRException

loadObject

public static Object loadObject(JasperReportsContext jasperReportsContext,
 URL url)
                         throws JRException

Throws:

JRException

loadObject

public static Object loadObject(InputStream is)
                         throws JRException

Throws:

JRException

loadObject

public static Object loadObject(JasperReportsContext jasperReportsContext,
 InputStream is)
                         throws JRException

Throws:

JRException

getInputStream

public static InputStream getInputStream(File file)
                                  throws JRException

Throws:

JRException

getInputStream

public static InputStream getInputStream(URL url)
                                  throws JRException

Throws:

JRException

loadBytes

public static byte[] loadBytes(File file)
                        throws JRException

Throws:

JRException

loadBytes

public static byte[] loadBytes(URL url)
                        throws JRException

Throws:

JRException

loadBytes

public static byte[] loadBytes(InputStream is)
                        throws JRException

Throws:

JRException

readBytes

public static byte[] readBytes(InputStream is)
                        throws IOException

Throws:

IOException

loadBytesFromResource

public static byte[] loadBytesFromResource(String resourceName)
                                    throws JRException

Throws:

JRException

loadBytesFromResource

public static byte[] loadBytesFromResource(String resourceName,
 ClassLoader classLoader)
                                    throws JRException

Throws:

JRException

getLocationInputStream

public static InputStream getLocationInputStream(String location)
                                          throws JRException

Tries to open an input stream for a location.

The method tries to interpret the location as a file name, a resource name or an URL. If any of these succeed, an input stream is created and returned.

Parameters:

location - the location

Returns:

an input stream if the location is an existing file name, a resource name on the classpath or an URL or null otherwise.

Throws:

JRException

getFileInputStream

public static InputStream getFileInputStream(String filename)
                                      throws JRException

Tries to open a file for reading.

Parameters:

filename - the file name

Returns:

an input stream for the file or null if the file was not found

Throws:

JRException

getResourceInputStream

public static InputStream getResourceInputStream(String resource)

Tries to open an input stream for a resource.

Parameters:

resource - the resource name

Returns:

an input stream for the resource or null if the resource was not found

getResources

public static List<URL> getResources(String resource)

Scans the context classloader and the classloader of this class for all resources that have a specified name, and returns a list of URLs for the found resources.

Parameters:

resource - the resource names

Returns:

a list of URLs of resources with the specified name; the list is empty if no resources have been found for the name

See Also:

• ClassLoader.getResources(String)

collectResources

protected static void collectResources(String resourceName,
 ClassLoader classLoader,
 Set<URL> resources)

getClassLoaderResources

public static List<ClassLoaderResource> getClassLoaderResources(String resource)

Scans the context classloader and the classloader of this class for all resources that have a specified name, and returns a list of ClassLoaderResource objects for the found resources.

The returned list contains the URLs of the resources, and for each resource the highest classloader in the classloader hierarchy on which the resource was found.

Parameters:

resource - the resource names

Returns:

a list of resources with the specified name; the list is empty if no resources have been found for the name

See Also:

• ClassLoader.getResources(String)

collectResources

protected static void collectResources(String resourceName,
 ClassLoader classLoader,
 Map<URL,ClassLoaderResource> resources)

getResource

public static URL getResource(String resource)

Returns the resource URL for a specified resource name.

Parameters:

resource - the resource name

Returns:

the URL of the resource having the specified name, or null if none found

See Also:

• ClassLoader.getResource(String)

getURLInputStream

public static InputStream getURLInputStream(String spec)
                                     throws JRException

Tries to open an input stream for an URL.

Parameters:

spec - the string to parse as an URL

Returns:

an input stream for the URL or null if spec is not a valid URL

Throws:

JRException

loadJasperPrintFromFile

public static JasperPrint loadJasperPrintFromFile(String fileName,
 JRVirtualizer virtualizer)
                                           throws JRException

Loads a JasperPrint object from a file, optionally using a virtualizer for the object.

Parameters:

fileName - the file name

virtualizer - the virtualizer

Returns:

a JasperPrint object

Throws:

JRException

See Also:

• JRVirtualizationHelper.setThreadVirtualizer(JRVirtualizer)

loadJasperPrint

public static JasperPrint loadJasperPrint(File file,
 JRVirtualizer virtualizer)
                                   throws JRException

Loads a JasperPrint object from a file, optionally using a virtualizer for the object.

Parameters:

file - the file

virtualizer - the virtualizer

Returns:

a JasperPrint object

Throws:

JRException

See Also:

• JRVirtualizationHelper.setThreadVirtualizer(JRVirtualizer)

loadJasperPrint

public static JasperPrint loadJasperPrint(URL url,
 JRVirtualizer virtualizer)
                                   throws JRException

Loads a JasperPrint object from a URL, optionally using a virtualizer for the object.

Parameters:

url - the URL

virtualizer - the virtualizer

Returns:

a JasperPrint object

Throws:

JRException

See Also:

• JRVirtualizationHelper.setThreadVirtualizer(JRVirtualizer)

loadJasperPrint

public static JasperPrint loadJasperPrint(InputStream is,
 JRVirtualizer virtualizer)
                                   throws JRException

Loads a JasperPrint object from a stream, optionally using a virtualizer for the object.

Parameters:

is - the stream

virtualizer - the virtualizer

Returns:

a JasperPrint object

Throws:

JRException

See Also:

• JRVirtualizationHelper.setThreadVirtualizer(JRVirtualizer)