JavaModelException


1   /*******************************************************************************
2    * Copyright (c) 2000, 2006 IBM Corporation and others.
3    * All rights reserved. This program and the accompanying materials
4    * are made available under the terms of the Eclipse Public License v1.0
5    * which accompanies this distribution, and is available at
6    * http://www.eclipse.org/legal/epl-v10.html
7    *
8    * Contributors:
9    *     IBM Corporation - initial API and implementation
10   *******************************************************************************/
11  package org.eclipse.jdt.core;
12  
13  import java.io.PrintStream  ;
14  import java.io.PrintWriter  ;
15  
16  import org.eclipse.core.runtime.CoreException;
17  import org.eclipse.core.runtime.IStatus;
18  
19  import org.eclipse.jdt.internal.core.JavaModelStatus;
20  
21  /**
22   * A checked exception representing a failure in the Java model.
23   * Java model exceptions contain a Java-specific status object describing the
24   * cause of the exception.
25   * <p>
26   * This class is not intended to be subclassed by clients. Instances of this
27   * class are automatically created by the Java model when problems arise, so
28   * there is generally no need for clients to create instances.
29   * </p>
30   *
31   * @see IJavaModelStatus
32   * @see IJavaModelStatusConstants
33   */
34  public class JavaModelException extends CoreException {
35  
36      private static final long serialVersionUID = -760398656505871287L; // backward compatible
37      
38      CoreException nestedCoreException;
39  /**
40   * Creates a Java model exception that wrappers the given <code>Throwable</code>.
41   * The exception contains a Java-specific status object with severity
42   * <code>IStatus.ERROR</code> and the given status code.
43   *
44   * @param e the <code>Throwable</code>
45   * @param code one of the Java-specific status codes declared in
46   *   <code>IJavaModelStatusConstants</code>
47   * @see IJavaModelStatusConstants
48   * @see org.eclipse.core.runtime.IStatus#ERROR
49   */
50  public JavaModelException(Throwable   e, int code) {
51      this(new JavaModelStatus(code, e)); 
52  }
53  /**
54   * Creates a Java model exception for the given <code>CoreException</code>.
55   * Equivalent to 
56   * <code>JavaModelException(exception,IJavaModelStatusConstants.CORE_EXCEPTION</code>.
57   *
58   * @param exception the <code>CoreException</code>
59   */
60  public JavaModelException(CoreException exception) {
61      super(exception.getStatus());
62      this.nestedCoreException = exception;
63  }
64  /**
65   * Creates a Java model exception for the given Java-specific status object.
66   *
67   * @param status the Java-specific status object
68   */
69  public JavaModelException(IJavaModelStatus status) {
70      super(status);
71  }
72  /**
73   * Returns the underlying <code>Throwable</code> that caused the failure.
74   *
75   * @return the wrappered <code>Throwable</code>, or <code>null</code> if the
76   *   direct case of the failure was at the Java model layer
77   */
78  public Throwable   getException() {
79      if (this.nestedCoreException == null) {
80          return getStatus().getException();
81      } else {
82          return this.nestedCoreException;
83      }
84  }
85  /**
86   * Returns the Java model status object for this exception.
87   * Equivalent to <code>(IJavaModelStatus) getStatus()</code>.
88   *
89   * @return a status object
90   */
91  public IJavaModelStatus getJavaModelStatus() {
92      IStatus status = this.getStatus();
93      if (status instanceof IJavaModelStatus) {
94          return (IJavaModelStatus)status;
95      } else {
96          // A regular IStatus is created only in the case of a CoreException.
97          // See bug 13492 Should handle JavaModelExceptions that contains CoreException more gracefully  
98          return new JavaModelStatus(this.nestedCoreException);
99      }
100 }
101 /**
102  * Returns whether this exception indicates that a Java model element does not
103  * exist. Such exceptions have a status with a code of
104  * <code>IJavaModelStatusConstants.ELEMENT_DOES_NOT_EXIST</code> or
105  * <code>IJavaModelStatusConstants.ELEMENT_NOT_ON_CLASSPATH</code>.
106  * This is a convenience method.
107  *
108  * @return <code>true</code> if this exception indicates that a Java model
109  *   element does not exist
110  * @see IJavaModelStatus#isDoesNotExist()
111  * @see IJavaModelStatusConstants#ELEMENT_DOES_NOT_EXIST
112  * @see IJavaModelStatusConstants#ELEMENT_NOT_ON_CLASSPATH
113  */
114 public boolean isDoesNotExist() {
115     IJavaModelStatus javaModelStatus = getJavaModelStatus();
116     return javaModelStatus != null && javaModelStatus.isDoesNotExist();
117 }
118 
119 /**
120  * Prints this exception's stack trace to the given print stream.
121  * 
122  * @param output the print stream
123  * @since 3.0
124  */
125 public void printStackTrace(PrintStream   output) {
126     synchronized(output) {
127         super.printStackTrace(output);
128         Throwable   throwable = getException();
129         if (throwable != null) {
130             output.print("Caused by: "); //$NON-NLS-1$
131             throwable.printStackTrace(output);
132         }
133     }
134 }
135 
136 /**
137  * Prints this exception's stack trace to the given print writer.
138  * 
139  * @param output the print writer
140  * @since 3.0
141  */
142 public void printStackTrace(PrintWriter   output) {
143     synchronized(output) {
144         super.printStackTrace(output);
145         Throwable   throwable = getException();
146         if (throwable != null) {
147             output.print("Caused by: "); //$NON-NLS-1$
148             throwable.printStackTrace(output);
149         }
150     }
151 }
152 /*
153  * Returns a printable representation of this exception suitable for debugging
154  * purposes only.
155  */
156 public String   toString() {
157     StringBuffer   buffer= new StringBuffer  ();
158     buffer.append("Java Model Exception: "); //$NON-NLS-1$
159     if (getException() != null) {
160         if (getException() instanceof CoreException) {
161             CoreException c= (CoreException)getException();
162             buffer.append("Core Exception [code "); //$NON-NLS-1$
163             buffer.append(c.getStatus().getCode());
164             buffer.append("] "); //$NON-NLS-1$
165             buffer.append(c.getStatus().getMessage());
166         } else {
167             buffer.append(getException().toString());
168         }
169     } else {
170         buffer.append(getStatus().toString());
171     }
172     return buffer.toString();
173 }
174 }
175
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