JDK14/Java14源码在线阅读
JDK14/Java14源码在线阅读 /
java.management /
share /
classes /
javax /
management /
openmbean /
package.html
<html>
<head>
<title>javax.management.openmbean package</title>
<!--
Copyright (c) 2001, 2017, Oracle and/or its affiliates. All rights reserved.
DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
This code is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License version 2 only, as
published by the Free Software Foundation. Oracle designates this
particular file as subject to the "Classpath" exception as provided
by Oracle in the LICENSE file that accompanied this code.
This code is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
version 2 for more details (a copy is included in the LICENSE file that
accompanied this code).
You should have received a copy of the GNU General Public License version
2 along with this work; if not, write to the Free Software Foundation,
Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
or visit www.oracle.com if you need additional information or have any
questions.
-->
</head>
<body bgcolor="white">
<p>Provides the open data types and Open MBean descriptor classes.
An <em>Open MBean</em> is an MBean where the types of attributes
and of operation parameters and return values are built using a
small set of predefined Java classes. Open MBeans facilitate
operation with remote management programs that do not necessarily
have access to application-specific types, including non-Java
programs.</p>
<p>Every MBean has an {@link javax.management.MBeanInfo
MBeanInfo} with information about the MBean itself, and its
attributes, operations, constructors, and notifications. In an
Open MBean, this <code>MBeanInfo</code> implements the {@link
javax.management.openmbean.OpenMBeanInfo OpenMBeanInfo}
interface, usually by being an instance of {@link
javax.management.openmbean.OpenMBeanInfoSupport
OpenMBeanInfoSupport}.</p>
<p>The attribute information returned by {@link
javax.management.MBeanInfo#getAttributes()
MBeanInfo.getAttributes} for an Open MBean is an array of
objects implementing {@link
javax.management.openmbean.OpenMBeanAttributeInfo
OpenMBeanAttributeInfo}, usually instances of {@link
javax.management.openmbean.OpenMBeanAttributeInfoSupport
OpenMBeanAttributeInfoSupport}. In addition to the usual
information about attributes, an
<code>OpenMBeanAttributeInfo</code> specifies the {@link
javax.management.openmbean.OpenType OpenType} of the attribute.
The possible <code>OpenType</code> values are predefined, which
is what ensures that remote managers will understand them.</p>
<p>Similar remarks apply to the parameter types of operations and
constructors, and to the return types of operations.</p>
<p>There is a distinction between an attribute's Java language
type, as returned by {@link
javax.management.MBeanAttributeInfo#getType() getType()}, and
its <code>OpenType</code>, as returned by {@link
javax.management.openmbean.OpenMBeanAttributeInfo#getOpenType()
getOpenType()}. For example, if the Java language type is
<code>java.lang.String</code>, the <code>OpenType</code> will be
{@link javax.management.openmbean.SimpleType#STRING
SimpleType.String}. If the Java language type is {@link
javax.management.openmbean.CompositeData}, the
<code>OpenType</code> will be a {@link
javax.management.openmbean.CompositeType CompositeType} that
describes the items in the <code>CompositeData</code> instances
for the attribute.</p>
<h2><a id="constraints">Default values and constraints</a></h2>
<p>In Open MBeans, attributes and parameters can have default values
and/or constraints associated with them in the {@code
OpenMBeanAttributeInfo} or {@code OpenMBeanParameterInfo}.
There are two ways to specify these constraints. Either the
values are directly specified as parameters to one of the
constructors of {@code OpenMBeanAttributeInfoSupport} or
{@code OpenMBeanParameterInfoSupport}, for example
{@link
javax.management.openmbean.OpenMBeanParameterInfoSupport#OpenMBeanParameterInfoSupport(
String, String, OpenType, Object, Object[])}; or the values are
specified in a {@link javax.management.Descriptor Descriptor} given
as a parameter to one of the constructors.</p>
<p>When a {@code Descriptor} is used, the fields of interest are
these:</p>
<ul>
<li>{@code defaultValue} defines the value returned by
{@link javax.management.openmbean.OpenMBeanParameterInfo#getDefaultValue()
getDefaultValue()};
<li>{@code minValue} defines the value returned by {@link
javax.management.openmbean.OpenMBeanParameterInfo#getMinValue() getMinValue()};
<li>{@code maxValue} defines the value returned by {@link
javax.management.openmbean.OpenMBeanParameterInfo#getMaxValue() getMaxValue()};
<li>{@code legalValues} defines the values returned by {@link
javax.management.openmbean.OpenMBeanParameterInfo#getLegalValues() getLegalValues()}.
</ul>
<p>For {@code defaultValue}, {@code minValue}, and {@code
maxValue}, the associated value must either be of the Java type
corresponding to {@code openType}, or be a string that can be
converted into that type. The conversion uses the static method
{@code valueOf(String)} if it finds one; otherwise a constructor
with a single {@code String} parameter if it finds one; otherwise
it fails.</p>
<p>For {@code legalValues}, the associated value must be either
an array or a {@code Set}, and the elements of the array or set
must be convertible as described for {@code defaultValue} etc.</p>
<p>The following conditions must be met for these fields:</p>
<ul>
/**代码未完, 请加载全部代码(NowJava.com).**/
关注时代Java
关注时代Java