我是Java编程的新手。我有一个要求，我需要连接到Mbean并执行某些任务，如启用，禁用，MBean计数。 enable方法用于启用Mbean，disable方法用于禁用，Count方法用于获取Mbean的计数。
在所有3种情况下，我需要连接到Mbean服务器。所以我决定编写一个通用方法来创建与服务器的连接，所以当在每个方法中调用任何方法时，我可以调用泛型方法。
我在存储不同对象时遇到的挑战，必须以泛型方法返回，以便我可以在禁用，启用和计数方法中使用对象值。
请参阅下面的代码，让我知道如何实现它。
package mbeanappscontrollerws;
import java.util.Hashtable;
import java.util.Iterator;
import java.util.Set;
import javax.management.remote.JMXConnectorFactory;
import javax.management.remote.JMXConnector;
import javax.management.remote.JMXServiceURL;
import oracle.oc4j.admin.jmx.remote.api.JMXConnectorConstant;
import java.net.MalformedURLException;
import java.io.IOException;
import java.util.regex.Pattern;
import javax.management.MBeanServerConnection;
import javax.management.MalformedObjectNameException;
import javax.management.ObjectName;
import javax.management.AttributeNotFoundException;
import javax.management.InstanceNotFoundException;
import javax.management.MBeanException;
import javax.management.ReflectionException;
public class MBeanAppsController {
public static void main(String[] args) {
try {
/* enable("******", "****", "****",
"*****", "****",
"***");
disable("******", "****", "****",
"*****", "****",
"***");
*/
} catch (Exception e) {
// TODO
}
}
public static MBeanServerConnection connectMethd(String host, String port,
String container,
String beanFQDN,
String usr, String pwd) {
/* MBean server URL */
String mbeanServerURL =
new String("service:jmx:rmi:" + "///opmn://" + host + ":" + port +
"/" + container);
/* credentials for authentication */
Hashtable cred = new Hashtable();
cred.put(JMXConnectorConstant.CREDENTIALS_LOGIN_KEY, (Object)usr);
cred.put(JMXConnectorConstant.CREDENTIALS_PASSWORD_KEY, (Object)pwd);
/* connection parameters */
Hashtable env = new Hashtable();
env.put(JMXConnectorFactory.PROTOCOL_PROVIDER_PACKAGES,
(Object)"oracle.oc4j.admin.jmx.remote");
env.put(JMXConnector.CREDENTIALS, (Object)cred);
/*System.out.println("env " + env);*/
JMXServiceURL jmxServerURL = null;
JMXConnector jmxConn = null;
MBeanServerConnection serverConn = null;
try {
/* connect to the MBean Server */
System.out.println("mbeanServerURL " + mbeanServerURL);
jmxServerURL = new JMXServiceURL(mbeanServerURL);
System.out.println("jmxServerURL " + jmxServerURL);
try {
jmxConn = JMXConnectorFactory.connect(jmxServerURL, env);
serverConn = jmxConn.getMBeanServerConnection();
} catch (IOException e) {
System.out.println(e);
}
}
catch (MalformedURLException e) {
}
return serverConn;
}
public static String[] enable(String host, String port, String container,
String beanFQDN, String usr, String pwd) {
String Output[] = new String[3];
try {
MBeanServerConnection serverConn =
connectMethd(host, port, container, beanFQDN, usr, pwd);
/* retrieve mbean app using the FQDN */
ObjectName mbeanName = new ObjectName(beanFQDN);
/* enable the MBean App */
serverConn.invoke(mbeanName, "startUp", null, null);
/* retrieve the running status of the MBean App after enabling */
Boolean mbeanAppRunning =
Boolean.valueOf(serverConn.getAttribute(mbeanName,
"Running").toString());
String beanAppStatus = "DISABLED";
if (mbeanAppRunning.booleanValue())
beanAppStatus = "ENABLED";
/* pattern to extract mbean application names */
Pattern mbeanAppPat =
Pattern.compile("name=", Pattern.CASE_INSENSITIVE);
String beanName = mbeanAppPat.split(beanFQDN)[1];
Output[0] = beanName;
Output[1] = beanFQDN;
Output[2] = beanAppStatus;
} catch (MalformedObjectNameException e) {
e.getStackTrace();
} catch (InstanceNotFoundException e) {
e.getStackTrace();
} catch (AttributeNotFoundException e) {
e.getStackTrace();
} catch (ReflectionException e) {
e.getStackTrace();
} catch (MBeanException e) {
e.getStackTrace();
} catch (IOException ioe) {
System.out.println(ioe);
}
System.out.println("Enable Method OutPut " + Output);
return Output;
}
public static String[] disable(String host, String port, String container,
String beanFQDN, String usr, String pwd) {
String Output[] = new String[3];
try {
MBeanServerConnection serverConn =
connectMethd(host, port, container, beanFQDN, usr, pwd);
/* retrieve mbean app using the FQDN */
ObjectName mbeanName = new ObjectName(beanFQDN);
/* enable the MBean App */
serverConn.invoke(mbeanName, "shutDown", null, null);
/* retrieve the running status of the MBean App after enabling */
Boolean mbeanAppRunning =
Boolean.valueOf(serverConn.getAttribute(mbeanName,
"Running").toString());
String beanAppStatus = "DISABLED";
if (mbeanAppRunning.booleanValue())
beanAppStatus = "ENABLED";
Pattern mbeanAppPat =
Pattern.compile("name=", Pattern.CASE_INSENSITIVE);
String beanName = mbeanAppPat.split(beanFQDN)[1];
/* debug */
System.out.println("Finished executing 'disable' operation.");
Output[0] = beanName;
Output[1] = beanFQDN;
Output[2] = beanAppStatus;
} catch (MalformedObjectNameException e) {
e.getStackTrace();
} catch (InstanceNotFoundException e) {
e.getStackTrace();
} catch (AttributeNotFoundException e) {
e.getStackTrace();
} catch (ReflectionException e) {
e.getStackTrace();
} catch (MBeanException e) {
e.getStackTrace();
} catch (IOException ioe) {
System.out.println(ioe);
}
System.out.println("Disable Method OutPut " + Output);
return Output;
}
public static int MBeancount(String host, String port, String container,
String filter, String usr, String pwd) {
int mbeanAppsCount = 0;
try {
MBeanServerConnection serverConn =
connectMethd(host, port, container, filter, usr, pwd);
ObjectName mbeanDomainName = new ObjectName(filter);
Set mbeanAppNames = serverConn.queryNames(mbeanDomainName, null);
/* retrieve mbean apps count */
Iterator i;
for (i = mbeanAppNames.iterator(); i.hasNext();
i.next(), mbeanAppsCount++)
;
} catch (MalformedObjectNameException e) {
/* debug */
System.out.println(e);
} catch (IOException ioe) {
System.out.println(ioe);
} finally {
/* debug */
System.out.println("End: MBeanAppsController-Java-getMBeanAppsCount");
try {
/* close server connection */
if (jmxConn != null) {
jmxConn.close();
} else {
}
} catch (IOException e) {
/* debug */
System.out.println(e);
}
}
System.out.println("mbeanAppsCount" + mbeanAppsCount);
return mbeanAppsCount;
}
}
在最后一个块下面的代码中，我无法从方法connect访问jmxconn变量，因为它是从JMXconnector派生的，但在泛型方法中我返回MBeanServerConnection类型。在我的情况下，我想要返回对象类型MBeanServerConnection和JMXconnector值。如果有人可以帮助我，那将是一个很大的帮助。
此致 TJ。
答案 0 :(得分：1)
一个丑陋/简单的解决方案是让connectMethd（sic）方法返回一个包含serverConn和jmxConn的数组：
更改其声明和返回语句，如下所示：
public static Object[] connectMethd(String host, String port,
String container,
String beanFQDN,
String usr, String pwd){
// same code as before here...
return new Object[]{serverConn,jmxConn};
}
调用connectMethd时，将结果放在Object[]变量中，并将索引0和1的元素转换为适当的类型。例子：
Object[] connections = connectMethd(host, port, container, beanFQDN, usr, pwd);
MBeanServerConnection serverConn = (MBeanServerConnection) connections[0];
JMXConnector jmxConn = (JMXConnector) connections[1];