/*
* @(#)TabularType.java 3.27 06/05/03
*
* Copyright 2006 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/
package javax.management.openmbean;
// java import
//
import java.util.List;
import java.util.Iterator;
import java.util.Arrays;
import java.util.ArrayList;
import java.util.Collections;
// jmx import
//
/**
* The <code>TabularType</code> class is the <i> open type</i> class
* whose instances describe the types of {@link TabularData <code>TabularData</code>} values.
*
* @version 3.27 06/05/03
* @author Sun Microsystems, Inc.
*
* @since 1.5
* @since.unbundled JMX 1.1
*/
public class TabularType extends OpenType<TabularData> {
/* Serial version */
static final long serialVersionUID = 6554071860220659261L;
/**
* @serial The composite type of rows
*/
private CompositeType rowType;
/**
* @serial The items used to index each row element, kept in the order the user gave
* This is an unmodifiable {@link ArrayList}
*/
private List<String> indexNames;
private transient Integer myHashCode = null; // As this instance is immutable, these two values
private transient String myToString = null; // need only be calculated once.
/* *** Constructor *** */
/**
* Constructs a <code>TabularType</code> instance, checking for the validity of the given parameters.
* The validity constraints are described below for each parameter.
* <p>
* The Java class name of tabular data values this tabular type represents
* (ie the class name returned by the {@link OpenType#getClassName() getClassName} method)
* is set to the string value returned by <code>TabularData.class.getName()</code>.
* <p>
* @param typeName The name given to the tabular type this instance represents; cannot be a null or empty string.
* <br>
* @param description The human readable description of the tabular type this instance represents;
* cannot be a null or empty string.
* <br>
* @param rowType The type of the row elements of tabular data values described by this tabular type instance;
* cannot be null.
* <br>
* @param indexNames The names of the items the values of which are used to uniquely index each row element in the
* tabular data values described by this tabular type instance;
* cannot be null or empty. Each element should be an item name defined in <var>rowType</var>
* (no null or empty string allowed).
* It is important to note that the <b>order</b> of the item names in <var>indexNames</var>
* is used by the methods {@link TabularData#get(java.lang.Object[]) <code>get</code>} and
* {@link TabularData#remove(java.lang.Object[]) <code>remove</code>} of class
* <code>TabularData</code> to match their array of values parameter to items.
* <br>
* @throws IllegalArgumentException if <var>rowType</var> is null,
* or <var>indexNames</var> is a null or empty array,
* or an element in <var>indexNames</var> is a null or empty string,
* or <var>typeName</var> or <var>description</var> is a null or empty string.
* <br>
* @throws OpenDataException if an element's value of <var>indexNames</var>
* is not an item name defined in <var>rowType</var>.
*/
public TabularType(String typeName,
String description,
CompositeType rowType,
String[] indexNames) throws OpenDataException {
// Check and initialize state defined by parent.
//
super(TabularData.class.getName(), typeName, description, false);
// Check rowType is not null
//
if (rowType == null) {
throw new IllegalArgumentException("Argument rowType cannot be null.");
}
// Check indexNames is neither null nor empty and does not contain any null element or empty string
//
checkForNullElement(indexNames, "indexNames");
checkForEmptyString(indexNames, "indexNames");
// Check all indexNames values are valid item names for rowType
//
for (int i=0; i<indexNames.length; i++) {
if ( ! rowType.containsKey(indexNames[i]) ) {
throw new OpenDataException("Argument's element value indexNames["+ i +"]=\""+ indexNames[i] +
"\" is not a valid item name for rowType.");
}
}
// initialize rowType
//
this.rowType = rowType;
// initialize indexNames (copy content so that subsequent
// modifs to the array referenced by the indexNames parameter
// have no impact)
//
List<String> tmpList = new ArrayList<String>(indexNames.length + 1);
for (int i=0; i<indexNames.length; i++) {
tmpList.add(indexNames[i]);
}
this.indexNames = Collections.unmodifiableList(tmpList);
}
/**
* Checks that Object[] arg is neither null nor empty (ie length==0)
* and that it does not contain any null element.
*/
private static void checkForNullElement(Object[] arg, String argName) {
if ( (arg == null) || (arg.length == 0) ) {
throw new IllegalArgumentException("Argument "+ argName +"[] cannot be null or empty.");
}
for (int i=0; i<arg.length; i++) {
if (arg[i] == null) {
throw new IllegalArgumentException("Argument's element "+ argName +"["+ i +"] cannot be null.");
}
}
}
/**
* Checks that String[] does not contain any empty (or blank characters only) string.
*/
private static void checkForEmptyString(String[] arg, String argName) {
for (int i=0; i<arg.length; i++) {
if (arg[i].trim().equals("")) {
throw new IllegalArgumentException("Argument's element "+ argName +"["+ i +"] cannot be an empty string.");
}
}
}
/* *** Tabular type specific information methods *** */
/**
* Returns the type of the row elements of tabular data values
* described by this <code>TabularType</code> instance.
*
* @return the type of each row.
*/
public CompositeType getRowType() {
return rowType;
}
/**
* <p>Returns, in the same order as was given to this instance's
* constructor, an unmodifiable List of the names of the items the
* values of which are used to uniquely index each row element of
* tabular data values described by this <code>TabularType</code>
* instance.</p>
*
* @return a List of String representing the names of the index
* items.
*
*/
public List<String> getIndexNames() {
return indexNames;
}
/**
* Tests whether <var>obj</var> is a value which could be
* described by this <code>TabularType</code> instance.
*
* <p>If <var>obj</var> is null or is not an instance of
* <code>javax.management.openmbean.TabularData</code>,
* <code>isValue</code> returns <code>false</code>.</p>
*
* <p>If <var>obj</var> is an instance of
* <code>javax.management.openmbean.TabularData</code>, say {@code
* td}, the result is true if this {@code TabularType} is
* <em>assignable from</em> {@link TabularData#getTabularType()
* td.getTabularType()}, as defined in {@link
* CompositeType#isValue CompositeType.isValue}.</p>
*
* @param obj the value whose open type is to be tested for
* compatibility with this <code>TabularType</code> instance.
*
* @return <code>true</code> if <var>obj</var> is a value for this
* tabular type, <code>false</code> otherwise.
*/
public boolean isValue(Object obj) {
// if obj is null or not a TabularData, return false
//
if (!(obj instanceof TabularData))
return false;
// if obj is not a TabularData, return false
//
TabularData value = (TabularData) obj;
TabularType valueType = value.getTabularType();
return isAssignableFrom(valueType);
}
@Override
boolean isAssignableFrom(OpenType ot) {
if (!(ot instanceof TabularType))
return false;
TabularType tt = (TabularType) ot;
if (!getTypeName().equals(tt.getTypeName()) ||
!getIndexNames().equals(tt.getIndexNames()))
return false;
return getRowType().isAssignableFrom(tt.getRowType());
}
/* *** Methods overriden from class Object *** */
/**
* Compares the specified <code>obj</code> parameter with this <code>TabularType</code> instance for equality.
* <p>
* Two <code>TabularType</code> instances are equal if and only if all of the following statements are true:
* <ul>
* <li>their type names are equal</li>
* <li>their row types are equal</li>
* <li>they use the same index names, in the same order</li>
* </ul>
* <br>
* @param obj the object to be compared for equality with this <code>TabularType</code> instance;
* if <var>obj</var> is <code>null</code>, <code>equals</code> returns <code>false</code>.
*
* @return <code>true</code> if the specified object is equal to this <code>TabularType</code> instance.
*/
public boolean equals(Object obj) {
// if obj is null, return false
//
if (obj == null) {
return false;
}
// if obj is not a TabularType, return false
//
TabularType other;
try {
other = (TabularType) obj;
} catch (ClassCastException e) {
return false;
}
// Now, really test for equality between this TabularType instance and the other:
//
// their names should be equal
if ( ! this.getTypeName().equals(other.getTypeName()) ) {
return false;
}
// their row types should be equal
if ( ! this.rowType.equals(other.rowType) ) {
return false;
}
// their index names should be equal and in the same order (ensured by List.equals())
if ( ! this.indexNames.equals(other.indexNames) ) {
return false;
}
// All tests for equality were successfull
//
return true;
}
/**
* Returns the hash code value for this <code>TabularType</code> instance.
* <p>
* The hash code of a <code>TabularType</code> instance is the sum of the hash codes
* of all elements of information used in <code>equals</code> comparisons
* (ie: name, row type, index names).
* This ensures that <code> t1.equals(t2) </code> implies that <code> t1.hashCode()==t2.hashCode() </code>
* for any two <code>TabularType</code> instances <code>t1</code> and <code>t2</code>,
* as required by the general contract of the method
* {@link Object#hashCode() Object.hashCode()}.
* <p>
* As <code>TabularType</code> instances are immutable, the hash code for this instance is calculated once,
* on the first call to <code>hashCode</code>, and then the same value is returned for subsequent calls.
*
* @return the hash code value for this <code>TabularType</code> instance
*/
public int hashCode() {
// Calculate the hash code value if it has not yet been done (ie 1st call to hashCode())
//
if (myHashCode == null) {
int value = 0;
value += this.getTypeName().hashCode();
value += this.rowType.hashCode();
for (Iterator k = indexNames.iterator(); k.hasNext(); ) {
value += k.next().hashCode();
}
myHashCode = new Integer(value);
}
// return always the same hash code for this instance (immutable)
//
return myHashCode.intValue();
}
/**
* Returns a string representation of this <code>TabularType</code> instance.
* <p>
* The string representation consists of the name of this class (ie <code>javax.management.openmbean.TabularType</code>),
* the type name for this instance, the row type string representation of this instance,
* and the index names of this instance.
* <p>
* As <code>TabularType</code> instances are immutable, the string representation for this instance is calculated once,
* on the first call to <code>toString</code>, and then the same value is returned for subsequent calls.
*
* @return a string representation of this <code>TabularType</code> instance
*/
public String toString() {
// Calculate the string representation if it has not yet been done (ie 1st call to toString())
//
if (myToString == null) {
StringBuffer result = new StringBuffer()
.append(this.getClass().getName())
.append("(name=")
.append(getTypeName())
.append(",rowType=")
.append(rowType.toString())
.append(",indexNames=(");
int i=0;
Iterator k = indexNames.iterator();
while( k.hasNext() ) {
if (i > 0) result.append(",");
result.append(k.next().toString());
i++;
}
result.append("))");
myToString = result.toString();
}
// return always the same string representation for this instance (immutable)
//
return myToString;
}
}
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