1 files changed, 204 insertions, 0 deletions
diff --git a/qpid/java/client/src/main/java/org/apache/qpid/filter/ConstantExpression.java b/qpid/java/client/src/main/java/org/apache/qpid/filter/ConstantExpression.java
new file mode 100644
index 0000000000..3874d13431
--- /dev/null
+++ b/qpid/java/client/src/main/java/org/apache/qpid/filter/ConstantExpression.java
@@ -0,0 +1,204 @@
+/* Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * 
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.qpid.filter;
+
+import java.math.BigDecimal;
+
+import org.apache.qpid.AMQInternalException;
+import org.apache.qpid.client.message.AbstractJMSMessage;
+
+/**
+ * Represents a constant expression
+ */
+public class ConstantExpression implements Expression
+{
+
+    static class BooleanConstantExpression extends ConstantExpression implements BooleanExpression
+    {
+        public BooleanConstantExpression(Object value)
+        {
+            super(value);
+        }
+
+        public boolean matches(AbstractJMSMessage message) throws AMQInternalException
+        {
+            Object object = evaluate(message);
+
+            return (object != null) && (object == Boolean.TRUE);
+        }
+    }
+
+    public static final BooleanConstantExpression NULL = new BooleanConstantExpression(null);
+    public static final BooleanConstantExpression TRUE = new BooleanConstantExpression(Boolean.TRUE);
+    public static final BooleanConstantExpression FALSE = new BooleanConstantExpression(Boolean.FALSE);
+
+    private Object value;
+
+    public static ConstantExpression createFromDecimal(String text)
+    {
+
+        // Strip off the 'l' or 'L' if needed.
+        if (text.endsWith("l") || text.endsWith("L"))
+        {
+            text = text.substring(0, text.length() - 1);
+        }
+
+        Number value;
+        try
+        {
+            value = new Long(text);
+        }
+        catch (NumberFormatException e)
+        {
+            // The number may be too big to fit in a long.
+            value = new BigDecimal(text);
+        }
+
+        long l = value.longValue();
+        if ((Integer.MIN_VALUE <= l) && (l <= Integer.MAX_VALUE))
+        {
+            value = new Integer(value.intValue());
+        }
+
+        return new ConstantExpression(value);
+    }
+
+    public static ConstantExpression createFromHex(String text)
+    {
+        Number value = new Long(Long.parseLong(text.substring(2), 16));
+        long l = value.longValue();
+        if ((Integer.MIN_VALUE <= l) && (l <= Integer.MAX_VALUE))
+        {
+            value = new Integer(value.intValue());
+        }
+
+        return new ConstantExpression(value);
+    }
+
+    public static ConstantExpression createFromOctal(String text)
+    {
+        Number value = new Long(Long.parseLong(text, 8));
+        long l = value.longValue();
+        if ((Integer.MIN_VALUE <= l) && (l <= Integer.MAX_VALUE))
+        {
+            value = new Integer(value.intValue());
+        }
+
+        return new ConstantExpression(value);
+    }
+
+    public static ConstantExpression createFloat(String text)
+    {
+        Number value = new Double(text);
+
+        return new ConstantExpression(value);
+    }
+
+    public ConstantExpression(Object value)
+    {
+        this.value = value;
+    }
+
+    public Object evaluate(AbstractJMSMessage message) throws AMQInternalException
+    {
+        return value;
+    }
+
+    public Object getValue()
+    {
+        return value;
+    }
+
+    /**
+     * @see Object#toString()
+     */
+    public String toString()
+    {
+        if (value == null)
+        {
+            return "NULL";
+        }
+
+        if (value instanceof Boolean)
+        {
+            return ((Boolean) value).booleanValue() ? "TRUE" : "FALSE";
+        }
+
+        if (value instanceof String)
+        {
+            return ConstantExpression.encodeString((String) value);
+        }
+
+        return value.toString();
+    }
+
+    /**
+     * TODO: more efficient hashCode()
+     *
+     * @see Object#hashCode()
+     */
+    public int hashCode()
+    {
+        return toString().hashCode();
+    }
+
+    /**
+     * TODO: more efficient hashCode()
+     *
+     * @see Object#equals(Object)
+     */
+    public boolean equals(Object o)
+    {
+
+        if ((o == null) || !this.getClass().equals(o.getClass()))
+        {
+            return false;
+        }
+
+        return toString().equals(o.toString());
+
+    }
+
+    /**
+     * Encodes the value of string so that it looks like it would look like
+     * when it was provided in a selector.
+     *
+     * @param s
+     * @return
+     */
+    public static String encodeString(String s)
+    {
+        StringBuffer b = new StringBuffer();
+        b.append('\'');
+        for (int i = 0; i < s.length(); i++)
+        {
+            char c = s.charAt(i);
+            if (c == '\'')
+            {
+                b.append(c);
+            }
+
+            b.append(c);
+        }
+
+        b.append('\'');
+
+        return b.toString();
+    }
+
+}