Author: luc
Date: Tue Jun 2 09:03:31 2009
New Revision: 780974
URL: http://svn.apache.org/viewvc?rev=780974&view=rev
Log:
added utility methods to help serialize/deserialize classes that
have RealVector/RealMatrix fields (possibly final) since the
top level interfaces are not serializable anymore
Modified:
commons/proper/math/trunk/src/java/org/apache/commons/math/linear/MatrixUtils.java
Modified:
commons/proper/math/trunk/src/java/org/apache/commons/math/linear/MatrixUtils.java
URL:
http://svn.apache.org/viewvc/commons/proper/math/trunk/src/java/org/apache/commons/math/linear/MatrixUtils.java?rev=780974&r1=780973&r2=780974&view=diff
==============================================================================
---
commons/proper/math/trunk/src/java/org/apache/commons/math/linear/MatrixUtils.java
(original)
+++
commons/proper/math/trunk/src/java/org/apache/commons/math/linear/MatrixUtils.java
Tue Jun 2 09:03:31 2009
@@ -17,6 +17,9 @@
package org.apache.commons.math.linear;
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
import java.lang.reflect.Array;
import java.math.BigDecimal;
import java.util.Arrays;
@@ -717,4 +720,214 @@
}
+ /** Serialize a {...@link RealVector}.
+ * <p>
+ * This method is intended to be called from within a private
+ * <code>writeObject</code> method (after a call to
+ * <code>oos.defaultWriteObject()</code>) in a class that has a
+ * {...@link RealVector} field, which should be declared
<code>transient</code>.
+ * This way, the default handling does not serialize the vector (the
{...@link
+ * RealVector} interface is not serializable by default) but this method
does
+ * serialize it specifically.
+ * </p>
+ * <p>
+ * The following example shows how a simple class with a name and a real
vector
+ * should be written:
+ * <pre><code>
+ * public class NamedVector implements Serializable {
+ *
+ * private final String name;
+ * private final transient RealVector coefficients;
+ *
+ * // omitted constructors, getters ...
+ *
+ * private void writeObject(ObjectOutputStream oos) throws IOException
{
+ * oos.defaultWriteObject(); // takes care of name field
+ * MatrixUtils.serializeRealVector(coefficients, oos);
+ * }
+ *
+ * private void readObject(ObjectInputStream ois) throws
ClassNotFoundException, IOException {
+ * ois.defaultReadObject(); // takes care of name field
+ * MatrixUtils.deserializeRealVector(this, "coefficients", ois);
+ * }
+ *
+ * }
+ * </code></pre>
+ * </p>
+ *
+ * @param vector real vector to serialize
+ * @param oos stream where the real vector should be written
+ * @exception IOException if object cannot be written to stream
+ * @see #deserializeRealVector(Object, String, ObjectInputStream)
+ */
+ public static void serializeRealVector(final RealVector vector,
+ final ObjectOutputStream oos)
+ throws IOException {
+ final int n = vector.getDimension();
+ oos.writeInt(n);
+ for (int i = 0; i < n; ++i) {
+ oos.writeDouble(vector.getEntry(i));
+ }
+ }
+
+ /** Deserialize a {...@link RealVector} field in a class.
+ * <p>
+ * This method is intended to be called from within a private
+ * <code>readObject</code> method (after a call to
+ * <code>ois.defaultReadObject()</code>) in a class that has a
+ * {...@link RealVector} field, which should be declared
<code>transient</code>.
+ * This way, the default handling does not deserialize the vector (the
{...@link
+ * RealVector} interface is not serializable by default) but this method
does
+ * deserialize it specifically.
+ * </p>
+ * @param instance instance in which the field must be set up
+ * @param fieldName name of the field within the class (may be private and
final)
+ * @param ois stream from which the real vector should be read
+ * @exception ClassNotFoundException if a class in the stream cannot be
found
+ * @exception IOException if object cannot be read from the stream
+ * @see #serializeRealVector(RealVector, ObjectOutputStream)
+ */
+ public static void deserializeRealVector(final Object instance,
+ final String fieldName,
+ final ObjectInputStream ois)
+ throws ClassNotFoundException, IOException {
+ try {
+
+ // read the vector data
+ final int n = ois.readInt();
+ final double[] data = new double[n];
+ for (int i = 0; i < n; ++i) {
+ data[i] = ois.readDouble();
+ }
+
+ // create the instance
+ final RealVector vector = new RealVectorImpl(data, false);
+
+ // set up the field
+ final java.lang.reflect.Field f =
+ instance.getClass().getDeclaredField(fieldName);
+ f.setAccessible(true);
+ f.set(instance, vector);
+
+ } catch (NoSuchFieldException nsfe) {
+ IOException ioe = new IOException();
+ ioe.initCause(nsfe);
+ throw ioe;
+ } catch (IllegalAccessException iae) {
+ IOException ioe = new IOException();
+ ioe.initCause(iae);
+ throw ioe;
+ }
+
+ }
+
+ /** Serialize a {...@link RealMatrix}.
+ * <p>
+ * This method is intended to be called from within a private
+ * <code>writeObject</code> method (after a call to
+ * <code>oos.defaultWriteObject()</code>) in a class that has a
+ * {...@link RealMatrix} field, which should be declared
<code>transient</code>.
+ * This way, the default handling does not serialize the matrix (the
{...@link
+ * RealMatrix} interface is not serializable by default) but this method
does
+ * serialize it specifically.
+ * </p>
+ * <p>
+ * The following example shows how a simple class with a name and a real
matrix
+ * should be written:
+ * <pre><code>
+ * public class NamedMatrix implements Serializable {
+ *
+ * private final String name;
+ * private final transient RealMatrix coefficients;
+ *
+ * // omitted constructors, getters ...
+ *
+ * private void writeObject(ObjectOutputStream oos) throws IOException
{
+ * oos.defaultWriteObject(); // takes care of name field
+ * MatrixUtils.serializeRealMatrix(coefficients, oos);
+ * }
+ *
+ * private void readObject(ObjectInputStream ois) throws
ClassNotFoundException, IOException {
+ * ois.defaultReadObject(); // takes care of name field
+ * MatrixUtils.deserializeRealMatrix(this, "coefficients", ois);
+ * }
+ *
+ * }
+ * </code></pre>
+ * </p>
+ *
+ * @param matrix real matrix to serialize
+ * @param oos stream where the real matrix should be written
+ * @exception IOException if object cannot be written to stream
+ * @see #deserializeRealMatrix(Object, String, ObjectInputStream)
+ */
+ public static void serializeRealMatrix(final RealMatrix matrix,
+ final ObjectOutputStream oos)
+ throws IOException {
+ final int n = matrix.getRowDimension();
+ final int m = matrix.getColumnDimension();
+ oos.writeInt(n);
+ oos.writeInt(m);
+ for (int i = 0; i < n; ++i) {
+ for (int j = 0; j < m; ++j) {
+ oos.writeDouble(matrix.getEntry(i, j));
+ }
+ }
+ }
+
+ /** Deserialize a {...@link RealMatrix} field in a class.
+ * <p>
+ * This method is intended to be called from within a private
+ * <code>readObject</code> method (after a call to
+ * <code>ois.defaultReadObject()</code>) in a class that has a
+ * {...@link RealMatrix} field, which should be declared
<code>transient</code>.
+ * This way, the default handling does not deserialize the matrix (the
{...@link
+ * RealMatrix} interface is not serializable by default) but this method
does
+ * deserialize it specifically.
+ * </p>
+ * @param instance instance in which the field must be set up
+ * @param fieldName name of the field within the class (may be private and
final)
+ * @param ois stream from which the real matrix should be read
+ * @exception ClassNotFoundException if a class in the stream cannot be
found
+ * @exception IOException if object cannot be read from the stream
+ * @see #serializeVector(RealVector, ObjectOutputStream)
+ */
+ public static void deserializeRealMatrix(final Object instance,
+ final String fieldName,
+ final ObjectInputStream ois)
+ throws ClassNotFoundException, IOException {
+ try {
+
+ // read the matrix data
+ final int n = ois.readInt();
+ final int m = ois.readInt();
+ final double[][] data = new double[n][m];
+ for (int i = 0; i < n; ++i) {
+ final double[] dataI = data[i];
+ for (int j = 0; j < m; ++j) {
+ dataI[j] = ois.readDouble();
+ }
+ }
+
+ // create the instance
+ final RealMatrix matrix = new RealMatrixImpl(data, false);
+
+ // set up the field
+ final java.lang.reflect.Field f =
+ instance.getClass().getDeclaredField(fieldName);
+ f.setAccessible(true);
+ f.set(instance, matrix);
+
+ } catch (NoSuchFieldException nsfe) {
+ IOException ioe = new IOException();
+ ioe.initCause(nsfe);
+ throw ioe;
+ } catch (IllegalAccessException iae) {
+ IOException ioe = new IOException();
+ ioe.initCause(iae);
+ throw ioe;
+ }
+
+ }
+
}
