Java tutorial
/******************************************************************************* * Copyright (c) 2000, 2011 IBM Corporation and others. * All rights reserved. This program and the accompanying materials * are made available under the terms of the Eclipse Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/epl-v10.html * * Contributors: * IBM Corporation - initial API and implementation *******************************************************************************/ package org.eclipse.core.resources; import java.util.Map; import org.eclipse.core.runtime.CoreException; import org.eclipse.core.runtime.IAdaptable; /** * Markers are a general mechanism for associating notes and meta-data with * resources. * <p> * Markers themselves are handles in the same way as <code>IResources</code> * are handles. Instances of <code>IMarker</code> do not hold the attributes * themselves but rather uniquely refer to the attribute container. As such, * their state may change underneath the handle with no warning to the holder * of the handle. * </p> * The Resources plug-in provides a general framework for * defining and manipulating markers and provides several standard marker types. * </p> * <p> * Each marker has:<ul> * <li> a type string, specifying its type (e.g. * <code>"org.eclipse.core.resources.taskmarker"</code>), </li> * <li> an identifier which is unique (relative to a particular resource)</li> * </ul> * Specific types of markers may carry additional information. * </p> * <p> * The resources plug-in defines five standard types: * <ul> * <li><code>org.eclipse.core.resources.marker</code></li> * <li><code>org.eclipse.core.resources.taskmarker</code></li> * <li><code>org.eclipse.core.resources.problemmarker</code></li> * <li><code>org.eclipse.core.resources.bookmark</code></li> * <li><code>org.eclipse.core.resources.textmarker</code></li> * </ul> * The plug-in also provides an extension point ( * <code>org.eclipse.core.resources.markers</code>) into which other * plug-ins can install marker type declaration extensions. * </p> * <p> * Marker types are declared within a multiple inheritance type system. * New markers are defined in the <code>plugin.xml</code> file of the * declaring plug-in. A valid declaration contains elements as defined by * the extension point DTD: * <ul> * <li><i>type</i> - the unique name of the marker type</li> * <li><i>super</i> - the list of marker types of which this marker is to be considered a sub-type</li> * <li><i>attributes</i> - the list of standard attributes which may be present on this type of marker</li> * <li><i>persistent</i> - whether markers of this type should be persisted by the platform</li> * </li> * </p> * <p>All markers declared as <code>persistent</code> are saved when the * workspace is saved, except those explicitly set as transient (the * <code>TRANSIENT</code> attribute is set as <code>true</code>). A plug-in * which defines a persistent marker is not directly involved in saving and * restoring the marker. Markers are not under version and configuration * management, and cannot be shared via VCM repositories. * </p> * <p> * Markers implement the <code>IAdaptable</code> interface; * extensions are managed by the platform's adapter manager. * </p> * * @noimplement This interface is not intended to be implemented by clients. * @noextend This interface is not intended to be extended by clients. */ public interface IMarker extends IAdaptable { /*==================================================================== * Marker types: *====================================================================*/ /** * Base marker type. * * @see #getType() */ public static final String MARKER = ResourcesPlugin.PI_RESOURCES + ".marker"; //$NON-NLS-1$ /** * Task marker type. * * @see #getType() */ public static final String TASK = ResourcesPlugin.PI_RESOURCES + ".taskmarker"; //$NON-NLS-1$ /** * Problem marker type. * * @see #getType() */ public static final String PROBLEM = ResourcesPlugin.PI_RESOURCES + ".problemmarker"; //$NON-NLS-1$ /** * Text marker type. * * @see #getType() */ public static final String TEXT = ResourcesPlugin.PI_RESOURCES + ".textmarker"; //$NON-NLS-1$ /** * Bookmark marker type. * * @see #getType() */ public static final String BOOKMARK = ResourcesPlugin.PI_RESOURCES + ".bookmark"; //$NON-NLS-1$ /*==================================================================== * Marker attributes: *====================================================================*/ /** * Severity marker attribute. A number from the set of error, warning and info * severities defined by the platform. * * @see #SEVERITY_ERROR * @see #SEVERITY_WARNING * @see #SEVERITY_INFO * @see #getAttribute(String, int) */ public static final String SEVERITY = "severity"; //$NON-NLS-1$ /** * Message marker attribute. A localized string describing the nature * of the marker (e.g., a name for a bookmark or task). The content * and form of this attribute is not specified or interpreted by the platform. * * @see #getAttribute(String, String) */ public static final String MESSAGE = "message"; //$NON-NLS-1$ /** * Location marker attribute. The location is a human-readable (localized) string which * can be used to distinguish between markers on a resource. As such it * should be concise and aimed at users. The content and * form of this attribute is not specified or interpreted by the platform. * * @see #getAttribute(String, String) */ public static final String LOCATION = "location"; //$NON-NLS-1$ /** * Priority marker attribute. A number from the set of high, normal and low * priorities defined by the platform. * * @see #PRIORITY_HIGH * @see #PRIORITY_NORMAL * @see #PRIORITY_LOW * @see #getAttribute(String, int) */ public static final String PRIORITY = "priority"; //$NON-NLS-1$ /** * Done marker attribute. A boolean value indicating whether * the marker (e.g., a task) is considered done. * * @see #getAttribute(String, String) */ public static final String DONE = "done"; //$NON-NLS-1$ /** * Character start marker attribute. An integer value indicating where a text * marker starts. This attribute is zero-relative and inclusive. * * @see #getAttribute(String, String) */ public static final String CHAR_START = "charStart"; //$NON-NLS-1$ /** * Character end marker attribute. An integer value indicating where a text * marker ends. This attribute is zero-relative and exclusive. * * @see #getAttribute(String, String) */ public static final String CHAR_END = "charEnd"; //$NON-NLS-1$ /** * Line number marker attribute. An integer value indicating the line number * for a text marker. This attribute is 1-relative. * * @see #getAttribute(String, String) */ public static final String LINE_NUMBER = "lineNumber"; //$NON-NLS-1$ /** * Transient marker attribute. A boolean value indicating whether the * marker (e. g., a task) is considered transient even if its type is * declared as persistent. * * @see #getAttribute(String, String) * @since 2.1 */ public static final String TRANSIENT = "transient"; //$NON-NLS-1$ /** * User editable marker attribute. A boolean value indicating whether a * user should be able to manually change the marker (e.g. a task). The * default is <code>true</code>. Note that the value of this attribute * is to be used by the UI as a suggestion and its value will NOT be * interpreted by Core in any manner and will not be enforced by Core * when performing any operations on markers. * * @see #getAttribute(String, String) * @since 2.1 */ public static final String USER_EDITABLE = "userEditable"; //$NON-NLS-1$ /** * Source id attribute. A string attribute that can be used by tools that * generate markers to indicate the source of the marker. Use of this attribute is * optional and its format or existence is not enforced. This attribute is * intended to improve serviceability by providing a value that product support * personnel or automated tools can use to determine appropriate help and * resolutions for markers. * * @see #getAttribute(String, String) * @since 3.3 */ public static final String SOURCE_ID = "sourceId"; //$NON-NLS-1$ /*==================================================================== * Marker attributes values: *====================================================================*/ /** * High priority constant (value 2). * * @see #getAttribute(String, int) */ public static final int PRIORITY_HIGH = 2; /** * Normal priority constant (value 1). * * @see #getAttribute(String, int) */ public static final int PRIORITY_NORMAL = 1; /** * Low priority constant (value 0). * * @see #getAttribute(String, int) */ public static final int PRIORITY_LOW = 0; /** * Error severity constant (value 2) indicating an error state. * * @see #getAttribute(String, int) */ public static final int SEVERITY_ERROR = 2; /** * Warning severity constant (value 1) indicating a warning. * * @see #getAttribute(String, int) */ public static final int SEVERITY_WARNING = 1; /** * Info severity constant (value 0) indicating information only. * * @see #getAttribute(String, int) */ public static final int SEVERITY_INFO = 0; /** * Deletes this marker from its associated resource. This method has no * effect if this marker does not exist. * * @exception CoreException if this marker could not be deleted. Reasons include: * <ul> * <li> Resource changes are disallowed during certain types of resource change * event notification. See <code>IResourceChangeEvent</code> for more details.</li> * </ul> * @see IResourceRuleFactory#markerRule(IResource) */ public void delete() throws CoreException; /** * Tests this marker for equality with the given object. * Two markers are equal if their id and resource are both equal. * * @param object the other object * @return an indication of whether the objects are equal */ public boolean equals(Object object); /** * Returns whether this marker exists in the workspace. A marker * exists if its resource exists and has a marker with the marker's id. * * @return <code>true</code> if this marker exists, otherwise * <code>false</code> */ public boolean exists(); /** * Returns the attribute with the given name. The result is an instance of one * of the following classes: <code>String</code>, <code>Integer</code>, * or <code>Boolean</code>. * Returns <code>null</code> if the attribute is undefined. * * @param attributeName the name of the attribute * @return the value, or <code>null</code> if the attribute is undefined. * @exception CoreException if this method fails. Reasons include: * <ul> * <li> This marker does not exist.</li> * </ul> */ public Object getAttribute(String attributeName) throws CoreException; /** * Returns the integer-valued attribute with the given name. * Returns the given default value if the attribute is undefined. * or the marker does not exist or is not an integer value. * * @param attributeName the name of the attribute * @param defaultValue the value to use if no value is found * @return the value or the default value if no value was found. */ public int getAttribute(String attributeName, int defaultValue); /** * Returns the string-valued attribute with the given name. * Returns the given default value if the attribute is undefined * or the marker does not exist or is not a string value. * * @param attributeName the name of the attribute * @param defaultValue the value to use if no value is found * @return the value or the default value if no value was found. */ public String getAttribute(String attributeName, String defaultValue); /** * Returns the boolean-valued attribute with the given name. * Returns the given default value if the attribute is undefined * or the marker does not exist or is not a boolean value. * * @param attributeName the name of the attribute * @param defaultValue the value to use if no value is found * @return the value or the default value if no value was found. */ public boolean getAttribute(String attributeName, boolean defaultValue); /** * Returns a map with all the attributes for the marker. * If the marker has no attributes then <code>null</code> is returned. * * @return a map of attribute keys and values (key type : <code>String</code> * value type : <code>String</code>, <code>Integer</code>, or * <code>Boolean</code>) or <code>null</code>. * @exception CoreException if this method fails. Reasons include: * <ul> * <li> This marker does not exist.</li> * </ul> */ public Map<String, Object> getAttributes() throws CoreException; /** * Returns the attributes with the given names. The result is an an array * whose elements correspond to the elements of the given attribute name * array. Each element is <code>null</code> or an instance of one * of the following classes: <code>String</code>, <code>Integer</code>, * or <code>Boolean</code>. * * @param attributeNames the names of the attributes * @return the values of the given attributes. * @exception CoreException if this method fails. Reasons include: * <ul> * <li> This marker does not exist.</li> * </ul> */ public Object[] getAttributes(String[] attributeNames) throws CoreException; /** * Returns the time at which this marker was created. * * @return the difference, measured in milliseconds, between the time at which * this marker was created and midnight, January 1, 1970 UTC, or <code>0L</code> * if the creation time is not known (this can occur in workspaces created using v2.0 or earlier). * @exception CoreException if this method fails. Reasons include: * <ul> * <li> This marker does not exist.</li> * </ul> * @since 2.1 */ public long getCreationTime() throws CoreException; /** * Returns the id of the marker. The id of a marker is unique * relative to the resource with which the marker is associated. * Marker ids are not globally unique. * * @return the id of the marker * @see IResource#findMarker(long) */ public long getId(); /** * Returns the resource with which this marker is associated. * * @return the resource with which this marker is associated */ public IResource getResource(); /** * Returns the type of this marker. The returned marker type will not be * <code>null</code>. * * @return the type of this marker * @exception CoreException if this method fails. Reasons include: * <ul> * <li> This marker does not exist.</li> * </ul> */ public String getType() throws CoreException; /** * Returns whether the type of this marker is considered to be a sub-type of * the given marker type. * * @return boolean <code>true</code>if the marker's type * is the same as (or a sub-type of) the given type. * @exception CoreException if this method fails. Reasons include: * <ul> * <li> This marker does not exist.</li> * </ul> */ public boolean isSubtypeOf(String superType) throws CoreException; /** * Sets the integer-valued attribute with the given name. * <p> * This method changes resources; these changes will be reported * in a subsequent resource change event, including an indication * that this marker has been modified. * </p> * * @param attributeName the name of the attribute * @param value the value * @exception CoreException if this method fails. Reasons include: * <ul> * <li> This marker does not exist.</li> * <li> Resource changes are disallowed during certain types of resource change * event notification. See <code>IResourceChangeEvent</code> for more details.</li> * </ul> * @see IResourceRuleFactory#markerRule(IResource) */ public void setAttribute(String attributeName, int value) throws CoreException; /** * Sets the attribute with the given name. The value must be <code>null</code> or * an instance of one of the following classes: * <code>String</code>, <code>Integer</code>, or <code>Boolean</code>. * If the value is <code>null</code>, the attribute is considered to be undefined. * * <p> * The attribute value cannot be <code>String</code> * whose UTF encoding exceeds 65535 bytes. On persistent * markers this limit is enforced by an assertion. * </p> * * <p> * This method changes resources; these changes will be reported * in a subsequent resource change event, including an indication * that this marker has been modified. * </p> * * @param attributeName the name of the attribute * @param value the value, or <code>null</code> if the attribute is to be undefined * @exception CoreException if this method fails. Reasons include: * <ul> * <li> This marker does not exist.</li> * <li> Resource changes are disallowed during certain types of resource change * event notification. See <code>IResourceChangeEvent</code> for more details.</li> * </ul> * @see IResourceRuleFactory#markerRule(IResource) */ public void setAttribute(String attributeName, Object value) throws CoreException; /** * Sets the boolean-valued attribute with the given name. * <p> * This method changes resources; these changes will be reported * in a subsequent resource change event, including an indication * that this marker has been modified. * </p> * * @param attributeName the name of the attribute * @param value the value * @exception CoreException if this method fails. Reasons include: * <ul> * <li> This marker does not exist.</li> * <li> Resource changes are disallowed during certain types of resource change * event notification. See <code>IResourceChangeEvent</code> for more details.</li> * </ul> * @see IResourceRuleFactory#markerRule(IResource) */ public void setAttribute(String attributeName, boolean value) throws CoreException; /** * Sets the given attribute key-value pairs on this marker. * The values must be <code>null</code> or an instance of * one of the following classes: <code>String</code>, * <code>Integer</code>, or <code>Boolean</code>. * If a value is <code>null</code>, the new value of the * attribute is considered to be undefined. * * <p> * The values of the attributes cannot be <code>String</code> * whose UTF encoding exceeds 65535 bytes. On persistent markers * this limit is enforced by an assertion. * </p> * * <p> * This method changes resources; these changes will be reported * in a subsequent resource change event, including an indication * that this marker has been modified. * </p> * * @param attributeNames an array of attribute names * @param values an array of attribute values * @exception CoreException if this method fails. Reasons include: * <ul> * <li> This marker does not exist.</li> * <li> Resource changes are disallowed during certain types of resource change * event notification. See <code>IResourceChangeEvent</code> for more details.</li> * </ul> * @see IResourceRuleFactory#markerRule(IResource) */ public void setAttributes(String[] attributeNames, Object[] values) throws CoreException; /** * Sets the attributes for this marker to be the ones contained in the * given table. The values must be an instance of one of the following classes: * <code>String</code>, <code>Integer</code>, or <code>Boolean</code>. * Attributes previously set on the marker but not included in the given map * are considered to be removals. Setting the given map to be <code>null</code> * is equivalent to removing all marker attributes. * * <p> * The values of the attributes cannot be <code>String</code> * whose UTF encoding exceeds 65535 bytes. On persistent markers * this limit is enforced by an assertion. * </p> * * <p> * This method changes resources; these changes will be reported * in a subsequent resource change event, including an indication * that this marker has been modified. * </p> * * @param attributes a map of attribute names to attribute values * (key type : <code>String</code> value type : <code>String</code>, * <code>Integer</code>, or <code>Boolean</code>) or <code>null</code> * @exception CoreException if this method fails. Reasons include: * <ul> * <li> This marker does not exist.</li> * <li> Resource changes are disallowed during certain types of resource change * event notification. See <code>IResourceChangeEvent</code> for more details.</li> * </ul> * @see IResourceRuleFactory#markerRule(IResource) */ public void setAttributes(Map<String, ? extends Object> attributes) throws CoreException; }