GAT Documentation

00001 package org.gridlab.gat;
00002 
00003 import java.util.Enumeration;
00004 import java.util.List;
00005 import java.util.Vector;
00006 
00007 import org.gridlab.gat.security.SecurityContext;
00008 
00009 /**
00010  * An instance of this class is the primary GAT state object.
00011  */
00012 public class GATContext implements Cloneable {
00013 
00014     /**
00015      * This member variable holds the preferences for this GATContext
00016      */
00017     private Preferences preferences = null;
00018 
00019     /**
00020      * This member variable holds the SecurityContext's for this GATcontext
00021      */
00022     private Vector securityContexts = null;
00023 
00024     /**
00025      * This no arguments constructor creates an instance of a GATContext.
00026      */
00027     public GATContext() {
00028         super();
00029 
00030         securityContexts = new Vector();
00031     }
00032 
00033     /**
00034      * Adds the passed SecurityContext.
00035      * 
00036      * @param securityContext
00037      *            A SecurityContext.
00038      */
00039     public void addSecurityContext(SecurityContext securityContext) {
00040         securityContexts.add(securityContext);
00041     }
00042 
00043     /**
00044      * Removes the passed SecurityContext.
00045      * 
00046      * @param securityContext
00047      *            A SecurityContext.
00048      */
00049     public void removeSecurityContext(SecurityContext securityContext) {
00050         securityContexts.remove(securityContext);
00051     }
00052 
00053     /**
00054      * Gets the list of SecurityContexts associated with this GATContext.
00055      * 
00056      * @return java.util.List of SecurityContexts.
00057      */
00058     public List getSecurityContexts() {
00059         return securityContexts;
00060     }
00061 
00062     /**
00063      * Gets a list of SecurityContexts of the specified type associated with
00064      * this GATContext.
00065      * 
00066      * @param type
00067      *            A SecurityContext type, a java.lang.String
00068      * @return java.util.List of SecurityContexts.
00069      */
00070     public List getSecurityContextsByType(String type) {
00071         SecurityContext nextSecurityContext;
00072         Vector typedSecurityContexts = new Vector();
00073 
00074         Enumeration enumeration = securityContexts.elements();
00075         while (enumeration.hasMoreElements()) {
00076             nextSecurityContext = (SecurityContext) enumeration.nextElement();
00077 
00078             if (type.equals(nextSecurityContext.getType())) {
00079                 typedSecurityContexts.add(nextSecurityContext);
00080             }
00081         }
00082 
00083         return typedSecurityContexts;
00084     }
00085 
00086     /**
00087      * Adds a Preferences object to the GATContext which will be used to choose
00088      * between adaptors if the constructor of an object is not called with a
00089      * Preferences object. Only one such object may be associated with the
00090      * GATContext at any one time.
00091      * 
00092      * @param preferences
00093      *            A Preferences object.
00094      */
00095     public void addPreferences(Preferences preferences) {
00096         this.preferences = preferences;
00097     }
00098 
00099     /**
00100      * Removes the Preferences object associated with the GATContext.
00101      */
00102     public void removePreferences() {
00103         preferences = null;
00104     }
00105 
00106     /**
00107      * Returns the Preferences object associated with the GATContext.
00108      */
00109     public Preferences getPreferences() {
00110         return preferences;
00111     }
00112 
00113     /**
00114      * Returns a clone of this context.
00115      */
00116     public Object clone() {
00117         return null;
00118     }
00119 }
GATContext.java
