Java tutorial
/* * Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package javax.print; import javax.print.attribute.Attribute; import javax.print.attribute.AttributeSet; import javax.print.attribute.PrintServiceAttribute; import javax.print.attribute.PrintServiceAttributeSet; import javax.print.event.PrintServiceAttributeListener; /** * Interface {@code PrintService} is the factory for a {@code DocPrintJob}. A * {@code PrintService} describes the capabilities of a printer and can be * queried regarding a printer's supported attributes. * <p> * Example: * <pre>{@code * DocFlavor flavor = DocFlavor.INPUT_STREAM.POSTSCRIPT; * PrintRequestAttributeSet aset = new HashPrintRequestAttributeSet(); * aset.add(MediaSizeName.ISO_A4); * PrintService[] pservices = * PrintServiceLookup.lookupPrintServices(flavor, aset); * if (pservices.length > 0) { * DocPrintJob pj = pservices[0].createPrintJob(); * try { * FileInputStream fis = new FileInputStream("test.ps"); * Doc doc = new SimpleDoc(fis, flavor, null); * pj.print(doc, aset); * } catch (FileNotFoundException fe) { * } catch (PrintException e) { * } * } * }</pre> */ public interface PrintService { /** * Returns a string name for this print service which may be used by * applications to request a particular print service. In a suitable * context, such as a name service, this name must be unique. In some * environments this unique name may be the same as the user friendly * printer name defined as the * {@link javax.print.attribute.standard.PrinterName PrinterName} attribute. * * @return name of the service */ public String getName(); /** * Creates and returns a {@code PrintJob} capable of handling data from any * of the supported document flavors. * * @return a {@code DocPrintJob} object */ public DocPrintJob createPrintJob(); /** * Registers a listener for events on this {@code PrintService}. * * @param listener a PrintServiceAttributeListener, which monitors the * status of a print service * @see #removePrintServiceAttributeListener */ public void addPrintServiceAttributeListener(PrintServiceAttributeListener listener); /** * Removes the print-service listener from this print service. This means * the listener is no longer interested in {@code PrintService} events. * * @param listener a {@code PrintServiceAttributeListener} object * @see #addPrintServiceAttributeListener */ public void removePrintServiceAttributeListener(PrintServiceAttributeListener listener); /** * Obtains this print service's set of printer description attributes giving * this Print Service's status. The returned attribute set object is * unmodifiable. The returned attribute set object is a "snapshot" of this * Print Service's attribute set at the time of the {@code getAttributes()} * method call: that is, the returned attribute set's contents will * <i>not</i> be updated if this print service's attribute set's contents * change in the future. To detect changes in attribute values, call * {@code getAttributes()} again and compare the new attribute set to the * previous attribute set; alternatively, register a listener for print * service events. * * @return unmodifiable snapshot of this Print Service's attribute set. May * be empty, but not {@code null}. */ public PrintServiceAttributeSet getAttributes(); /** * Gets the value of the single specified service attribute. This may be * useful to clients which only need the value of one attribute and want to * minimize overhead. * * @param <T> the type of the specified service attribute * @param category the category of a {@code PrintServiceAttribute} * supported by this service - may not be {@code null} * @return the value of the supported attribute or {@code null} if the * attribute is not supported by this service * @throws NullPointerException if the category is {@code null} * @throws IllegalArgumentException if {@code category} is not a * {@code Class} that implements interface * {@link PrintServiceAttribute PrintServiceAttribute} */ public <T extends PrintServiceAttribute> T getAttribute(Class<T> category); /** * Determines the print data formats a client can specify when setting up a * job for this {@code PrintService}. A print data format is designated by a * "doc flavor" (class {@link DocFlavor DocFlavor}) consisting of a MIME * type plus a print data representation class. * <p> * Note that some doc flavors may not be supported in combination with all * attributes. Use {@code getUnsupportedAttributes(..)} to validate specific * combinations. * * @return array of supported doc flavors, should have at least one element */ public DocFlavor[] getSupportedDocFlavors(); /** * Determines if this print service supports a specific {@code DocFlavor}. * This is a convenience method to determine if the {@code DocFlavor} would * be a member of the result of {@code getSupportedDocFlavors()}. * <p> * Note that some doc flavors may not be supported in combination with all * attributes. Use {@code getUnsupportedAttributes(..)} to validate specific * combinations. * * @param flavor the {@code DocFlavor} to query for support * @return {@code true} if this print service supports the specified * {@code DocFlavor}; {@code false} otherwise * @throws NullPointerException if {@code flavor} is {@code null} */ public boolean isDocFlavorSupported(DocFlavor flavor); /** * Determines the printing attribute categories a client can specify when * setting up a job for this print service. A printing attribute category is * designated by a {@code Class} that implements interface * {@link Attribute Attribute}. This method returns just the attribute * <i>categories</i> that are supported; it does not return the particular * attribute <i>values</i> that are supported. * <p> * This method returns all the printing attribute categories this print * service supports for any possible job. Some categories may not be * supported in a particular context (ie for a particular * {@code DocFlavor}). Use one of the methods that include a * {@code DocFlavor} to validate the request before submitting it, such as * {@code getSupportedAttributeValues(..)}. * * @return array of printing attribute categories that the client can * specify as a doc-level or job-level attribute in a Print Request. * Each element in the array is a {@link Class Class} that * implements interface {@link Attribute Attribute}. The array is * empty if no categories are supported. */ public Class<?>[] getSupportedAttributeCategories(); /** * Determines whether a client can specify the given printing attribute * category when setting up a job for this print service. A printing * attribute category is designated by a {@code Class} that implements * interface {@link Attribute Attribute}. This method * tells whether the attribute <i>category</i> is supported; it does not * tell whether a particular attribute <i>value</i> is supported. * <p> * Some categories may not be supported in a particular context (ie for a * particular {@code DocFlavor}). Use one of the methods which include a * {@code DocFlavor} to validate the request before submitting it, such as * {@code getSupportedAttributeValues(..)}. * <p> * This is a convenience method to determine if the category would be a * member of the result of {@code getSupportedAttributeCategories()}. * * @param category printing attribute category to test. It must be a * {@code Class} that implements interface * {@link Attribute Attribute}. * @return {@code true} if this print service supports specifying a * doc-level or job-level attribute in {@code category} in a Print * Request; {@code false} if it doesn't * @throws NullPointerException if {@code category} is {@code null} * @throws IllegalArgumentException if {@code category} is not a * {@code Class} that implements interface * {@link Attribute Attribute} */ public boolean isAttributeCategorySupported(Class<? extends Attribute> category); /** * Determines this print service's default printing attribute value in the * given category. A printing attribute value is an instance of a class that * implements interface {@link Attribute Attribute}. If a client sets up a * print job and does not specify any attribute value in the given category, * this Print Service will use the default attribute value instead. * <p> * Some attributes may not be supported in a particular context (ie for a * particular {@code DocFlavor}). Use one of the methods that include a * {@code DocFlavor} to validate the request before submitting it, such as * {@code getSupportedAttributeValues(..)}. * <p> * Not all attributes have a default value. For example the service will not * have a default value for {@code RequestingUser} i.e. a {@code null} * return for a supported category means there is no service default value * for that category. Use the {@code isAttributeCategorySupported(Class)} * method to distinguish these cases. * * @param category printing attribute category for which the default * attribute value is requested. It must be a {@link Class Class} * that implements interface {@link Attribute Attribute}. * @return default attribute value for {@code category}, or {@code null} if * this Print Service does not support specifying a doc-level or * job-level attribute in {@code category} in a Print Request, or * the service does not have a default value for this attribute * @throws NullPointerException if {@code category} is {@code null} * @throws IllegalArgumentException if {@code category} is not a * {@link Class Class} that implements interface * {@link Attribute Attribute} */ public Object getDefaultAttributeValue(Class<? extends Attribute> category); /** * Determines the printing attribute values a client can specify in the * given category when setting up a job for this print service. A printing * attribute value is an instance of a class that implements interface * {@link Attribute Attribute}. * <p> * If {@code flavor} is {@code null} and {@code attributes} is {@code null} * or is an empty set, this method returns all the printing attribute values * this Print Service supports for any possible job. If {@code flavor} is not * {@code null} or {@code attributes} is not an empty set, this method * returns just the printing attribute values that are compatible with the * given doc flavor and/or set of attributes. That is, a {@code null} return * value may indicate that specifying this attribute is incompatible with * the specified DocFlavor. Also if {@code DocFlavor} is not {@code null} it * must be a flavor supported by this {@code PrintService}, else * {@code IllegalArgumentException} will be thrown. * <p> * If the {@code attributes} parameter contains an {@code Attribute} whose * category is the same as the {@code category} parameter, the service must * ignore this attribute in the {@code AttributeSet}. * <p> * {@code DocAttribute}s which are to be specified on the {@code Doc} must * be included in this set to accurately represent the context. * <p> * This method returns an {@code Object} because different printing * attribute categories indicate the supported attribute values in different * ways. The documentation for each printing attribute in package * {@link javax.print.attribute.standard javax.print.attribute.standard} * describes how each attribute indicates its supported values. Possible * ways of indicating support include: * <ul> * <li>Return a single instance of the attribute category to indicate that * any value is legal -- used, for example, by an attribute whose value is * an arbitrary text string. (The value of the returned attribute object * is irrelevant.) * <li>Return an array of one or more instances of the attribute category, * containing the legal values -- used, for example, by an attribute with * a list of enumerated values. The type of the array is an array of the * specified attribute category type as returned by its * {@code getCategory(Class)}. * <li>Return a single object (of some class other than the attribute * category) that indicates bounds on the legal values -- used, for * example, by an integer-valued attribute that must lie within a certain * range. * </ul> * * @param category printing attribute category to test. It must be a * {@link Class Class} that implements interface * {@link Attribute Attribute}. * @param flavor doc flavor for a supposed job, or {@code null} * @param attributes set of printing attributes for a supposed job (both * job-level attributes and document-level attributes), or * {@code null} * @return object indicating supported values for {@code category}, or * {@code null} if this Print Service does not support specifying a * doc-level or job-level attribute in {@code category} in a Print * Request * @throws NullPointerException if {@code category} is {@code null} * @throws IllegalArgumentException if {@code category} is not a * {@link Class Class} that implements interface * {@link Attribute Attribute}, or {@code DocFlavor} is not * supported by this service */ public Object getSupportedAttributeValues(Class<? extends Attribute> category, DocFlavor flavor, AttributeSet attributes); /** * Determines whether a client can specify the given printing attribute * value when setting up a job for this Print Service. A printing attribute * value is an instance of a class that implements interface * {@link Attribute Attribute}. * <p> * If {@code flavor} is {@code null} and {@code attributes} is {@code null} * or is an empty set, this method tells whether this Print Service supports * the given printing attribute value for some possible combination of doc * flavor and set of attributes. If {@code flavor} is not {@code null} or * {@code attributes} is not an empty set, this method tells whether this * Print Service supports the given printing attribute value in combination * with the given doc flavor and/or set of attributes. * <p> * Also if {@code DocFlavor} is not {@code null} it must be a flavor * supported by this {@code PrintService}, else * {@code IllegalArgumentException} will be thrown. * <p> * {@code DocAttribute}s which are to be specified on the {@code Doc} must * be included in this set to accurately represent the context. * <p> * This is a convenience method to determine if the value would be a member * of the result of {@code getSupportedAttributeValues(...)}. * * @param attrval printing attribute value to test * @param flavor doc flavor for a supposed job, or {@code null} * @param attributes set of printing attributes for a supposed job (both * job-level attributes and document-level attributes), or * {@code null} * @return {@code true} if this Print Service supports specifying * {@code attrval} as a doc-level or job-level attribute in a Print * Request, {@code false} if it doesn't * @throws NullPointerException if {@code attrval} is {@code null} * @throws IllegalArgumentException if flavor is not supported by this * {@code PrintService} */ public boolean isAttributeValueSupported(Attribute attrval, DocFlavor flavor, AttributeSet attributes); /** * Identifies the attributes that are unsupported for a print request in the * context of a particular {@code DocFlavor}. This method is useful for * validating a potential print job and identifying the specific attributes * which cannot be supported. It is important to supply only a supported * {@code DocFlavor} or an {@code IllegalArgumentException} will be thrown. * If the return value from this method is {@code null}, all attributes are * supported. * <p> * {@code DocAttribute}s which are to be specified on the {@code Doc} must * be included in this set to accurately represent the context. * <p> * If the return value is {@code non-null}, all attributes in the returned * set are unsupported with this {@code DocFlavor}. The returned set does * not distinguish attribute categories that are unsupported from * unsupported attribute values. * <p> * A supported print request can then be created by removing all unsupported * attributes from the original attribute set, except in the case that the * {@code DocFlavor} is unsupported. * <p> * If any attributes are unsupported only because they are in conflict with * other attributes then it is at the discretion of the service to select * the attribute(s) to be identified as the cause of the conflict. * <p> * Use {@code isDocFlavorSupported()} to verify that a {@code DocFlavor} is * supported before calling this method. * * @param flavor doc flavor to test, or {@code null} * @param attributes set of printing attributes for a supposed job (both * job-level attributes and document-level attributes), or * {@code null} * @return {@code null} if this Print Service supports the print request * specification, else the unsupported attributes * @throws IllegalArgumentException if {@code flavor} is not supported by * this {@code PrintService} */ public AttributeSet getUnsupportedAttributes(DocFlavor flavor, AttributeSet attributes); /** * Returns a factory for UI components which allow users to interact with * the service in various roles. Services which do not provide any UI should * return {@code null}. Print Services which do provide UI but want to be * supported in an environment with no UI support should ensure that the * factory is not initialised unless the application calls this method to * obtain the factory. See {@code ServiceUIFactory} for more information. * * @return {@code null} or a factory for UI components */ public ServiceUIFactory getServiceUIFactory(); /** * Determines if two services are referring to the same underlying service. * Objects encapsulating a print service may not exhibit equality of * reference even though they refer to the same underlying service. * <p> * Clients should call this method to determine if two services are * referring to the same underlying service. * <p> * Services must implement this method and return {@code true} only if the * service objects being compared may be used interchangeably by the client. * Services are free to return the same object reference to an underlying * service if that, but clients must not depend on equality of reference. * * @param obj the reference object with which to compare * @return {@code true} if this service is the same as the obj argument, * {@code false} otherwise */ public boolean equals(Object obj); /** * This method should be implemented consistently with * {@code equals(Object)}. * * @return hash code of this object */ public int hashCode(); }