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src/java.base/share/classes/java/lang/ClassNotFoundException.java
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@@ -23,10 +23,15 @@
* questions.
*/
package java.lang;
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.io.ObjectStreamField;
+
/**
* Thrown when an application tries to load in a class through its
* string name using:
* <ul>
* <li>The <code>forName</code> method in class <code>Class</code>.
@@ -55,19 +60,10 @@
* use serialVersionUID from JDK 1.1.X for interoperability
*/
private static final long serialVersionUID = 9176873029745254542L;
/**
- * This field holds the exception ex if the
- * ClassNotFoundException(String s, Throwable ex) constructor was
- * used to instantiate the object
- * @serial
- * @since 1.2
- */
- private Throwable ex;
-
- /**
* Constructs a <code>ClassNotFoundException</code> with no detail message.
*/
public ClassNotFoundException() {
super((Throwable)null); // Disallow initCause
}
@@ -90,12 +86,11 @@
* @param s the detail message
* @param ex the exception that was raised while loading the class
* @since 1.2
*/
public ClassNotFoundException(String s, Throwable ex) {
- super(s, null); // Disallow initCause
- this.ex = ex;
+ super(s, ex); // Disallow initCause
}
/**
* Returns the exception that was raised if an error occurred while
* attempting to load the class. Otherwise, returns {@code null}.
@@ -106,20 +101,44 @@
*
* @return the <code>Exception</code> that was raised while loading a class
* @since 1.2
*/
public Throwable getException() {
- return ex;
+ return super.getCause();
}
/**
- * Returns the cause of this exception (the exception that was raised
- * if an error occurred while attempting to load the class; otherwise
- * {@code null}).
+ * Serializable fields for ClassNotFoundException.
*
- * @return the cause of this exception.
- * @since 1.4
+ * @serialField ex Throwable
*/
- public Throwable getCause() {
- return ex;
+ private static final ObjectStreamField[] serialPersistentFields = {
+ new ObjectStreamField("ex", Throwable.class)
+ };
+
+ /*
+ * Reconstitutes the ClassNotFoundException instance from a stream
+ * and initialize the cause properly when deserializing from an older
+ * version.
+ *
+ * The getException and getCause method returns the private "ex" field
+ * in the older implementation and ClassNotFoundException::cause
+ * was set to null.
+ */
+ private void readObject(ObjectInputStream s) throws IOException, ClassNotFoundException {
+ ObjectInputStream.GetField fields = s.readFields();
+ Throwable exception = (Throwable) fields.get("ex", null);
+ if (exception != null) {
+ setCause(exception);
+ }
+ }
+
+ /*
+ * To maintain compatibility with older implementation, write a serial
+ * "ex" field with the cause as the value.
+ */
+ private void writeObject(ObjectOutputStream out) throws IOException {
+ ObjectOutputStream.PutField fields = out.putFields();
+ fields.put("ex", super.getCause());
+ out.writeFields();
}
}
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