I want to know how to return all values of a array variable which are assigned in for loop.
In the method below, I am assigning values to an Output array. Now I want to display all the value in the Output array as return argument. Because of scope level, I am getting the last value.
Right now I am able to return one the last value because of the scope issue.
public static String[] getMBeanAppsStatus(String host, String port,
String container, String filter,
String usr, String pwd) {
String Output[] = new String[3];
int mbeanAppsIdx = 0;
int LVar = mbeanAppsIdx;
try {
Object[] connections =
connectMethd(host, port, container, filter, usr, pwd);
MBeanServerConnection serverConn =
(MBeanServerConnection)connections[0];
System.out.println("serverConn from array variable in getMBeanAppsStatus" +
serverConn);
/* retrieve mbean apps matching given filter */
ObjectName mbeanDomainName = new ObjectName(filter);
Set mbeanAppNames = serverConn.queryNames(mbeanDomainName, null);
/* pattern to extract mbean application names */
Pattern mbeanAppPat =
Pattern.compile("name=", Pattern.CASE_INSENSITIVE);
/* mbean application name */
ObjectName mbeanApp = null;
/* retrieve mbean apps count */
Iterator i;
for (i = mbeanAppNames.iterator(); i.hasNext(); ) {
mbeanAppsIdx++;
System.out.println("Populating MBean App #" + mbeanAppsIdx +
"details...");
/* retrieve mbean app name and status */
mbeanApp = (ObjectName)i.next();
String mbeanAppFQDN = mbeanApp.toString();
String mbeanAppName = mbeanAppPat.split(mbeanAppFQDN)[1];
Boolean mbeanAppRunning =
Boolean.valueOf(serverConn.getAttribute(mbeanApp,
"Running").toString());
String mbeanAppStatus = "DISABLED";
if (mbeanAppRunning.booleanValue())
mbeanAppStatus = "ENABLED";
Output[0] = mbeanAppName;
Output[1] = mbeanAppFQDN;
Output[2] = mbeanAppStatus;
System.out.println("getMBeanAppsStatus output " +
"mbeanAppName " + mbeanAppName +
" mbeanAppFQDN " + mbeanAppFQDN +
" mbeanAppStatus : " + mbeanAppStatus);
}
} 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("getMBeanAppsStatus Output " + Output);
return Output;
}
Basically, I am trying to convert the above method to a J2EE webservice and the response from the web service will be a return value of Output from the method.
I have 2 issues here in method which i want to rectify it.
1) Want to concatenate the value of mbeanAppName, mbeanAppFQDN and mbeanAppStatus with comma , separator and assign to array variable.
2) Return the array result which should hold all the previous values also.
You are only seeing the last ouput because at each iteration, you are overwritting the previous output with the current one.
You can use a StringBuilder to concatenate mbeanAppName, mbeanAppFQDN and mbeanAppStatus separated by a comma ,. This can be accomplished in the following way:
StringBuilder sb = new StringBuilder();
/* Declare and initialise variables somewhere in between*/
sb.append(mbeanAppName);
sb.append(",");
sb.append(mbeanAppFQDN);
sb.append(",");
sb.append(mbeanAppStatus);
String generatedStringOutputFromStringBuilder = sb.toString();
You can use a List to store the output after each iteration. Unlike an array, a List can change size. You don't have to declare its when when you initialise it. Add the output to the created List at each iteration. For example:
List<String> output = new ArrayList<String>();
/* Declare and initialise variables somewhere in between*/
output.add(generatedStringOutputFromStringBuilder);
Here is the corrected sample that should set you in the right direction.
public static List<String> getMBeanAppsStatus(String host, String port,
String container, String filter,
String usr, String pwd) {
// A new List
List<String> output = new ArrayList<String>();
//A StringBuilder that will be used to build each ouput String
StringBuilder sb = new StringBuilder();
int mbeanAppsIdx = 0;
int LVar = mbeanAppsIdx;
try {
Object[] connections = connectMethd(host, port, container, filter, usr, pwd);
MBeanServerConnection serverConn = (MBeanServerConnection)connections[0];
System.out.println("serverConn from array variable in getMBeanAppsStatus" + serverConn);
/* retrieve mbean apps matching given filter */
ObjectName mbeanDomainName = new ObjectName(filter);
Set mbeanAppNames = serverConn.queryNames(mbeanDomainName, null);
/* pattern to extract mbean application names */
Pattern mbeanAppPat = Pattern.compile("name=", Pattern.CASE_INSENSITIVE);
/* mbean application name */
ObjectName mbeanApp = null;
/* retrieve mbean apps count */
Iterator i;
for (i = mbeanAppNames.iterator(); i.hasNext(); ) {
mbeanAppsIdx++;
System.out.println("Populating MBean App #" + mbeanAppsIdx + "details...");
/* retrieve mbean app name and status */
mbeanApp = (ObjectName)i.next();
String mbeanAppFQDN = mbeanApp.toString();
String mbeanAppName = mbeanAppPat.split(mbeanAppFQDN)[1];
Boolean mbeanAppRunning = Boolean.valueOf(serverConn.getAttribute(mbeanApp, "Running").toString());
String mbeanAppStatus = "DISABLED";
if (mbeanAppRunning.booleanValue())
mbeanAppStatus = "ENABLED";
// Construct the output using a string builder as
// mbeanAppName,mbeanAppFQDN,mbeanAppStatus
sb.append(mbeanAppName);
sb.append(",");
sb.append(mbeanAppFQDN);
sb.append(",");
sb.append(mbeanAppStatus);
// Store the current ouput in the List output
output.add(sb.toString());
// Empty string builder
sb.setLength(0)
System.out.println("getMBeanAppsStatus output " +
"mbeanAppName " + mbeanAppName +
" mbeanAppFQDN " + mbeanAppFQDN +
" mbeanAppStatus : " + mbeanAppStatus);
}
} 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("getMBeanAppsStatus Output " + output);
return output;
}