Wiki source code of JMX plugin

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1 {{content/}}
2
3 == IMonitorPlugin ==
4
5 === Use cases ===
6
7 This type of plugin allows you to perform monitoring via the JMX interface. It can be used to monitor custom plugins or to check the availability of third-party web services.
8
9 === Method signatures ===
10
11 {{code language="java"}}
12 /**
13 * This methods gets called every time the monitor queries the state of the monitoring plugin. To indicate that there
14 * is no error, this method must return the value of the constant 'IMonitorPlugin.CHECK_SUCCESS'.
15 * To indicate an error, the following options exist:
16 * - This method throws a Java exception.
17 * - This method returns an error message that will be shown in the monitoring MBean. You can either use
18 * a custom error message or use the value of the constant 'IMonitorPlugin.CHECK_ERROR'. However, make sure you do
19 * not accidentally return the value of the constant 'IMonitorPlugin.CHECK_SUCCESS'.
20 */
21 public String check()
22
23 /**
24 * Can be used for custom initialization. Do not use the constructor.
25 * Initialization happens once, the 'check' method is then called multiple times as necessary.
26 * The default implementation does nothing.
27 */
28 public void init()
29
30 /**
31 * Can be used for custom actions when the plugin is destroyed. The default implementation does nothing.
32 */
33 public void shutdown()
34 {{/code}}
35
36 === Examples ===
37
38 Example 1: The following code shows how to check the availability of some third-party web service, here //http:~/~/example.com//.
39
40 {{code language="java"}}
41
42 import java.net.HttpURLConnection;
43 import java.net.URL;
44
45 import de.xima.fc.plugin.interfaces.IMonitorPlugin;
46
47 public class MyMonitor implements IMonitorPlugin {
48
49 @Override
50 public String check() {
51 try {
52 URL url = new URL("http://example.com");
53 HttpURLConnection urlConnection = null;
54 // Open a connection to http://example.com
55 urlConnection = (HttpURLConnection)url.openConnection();
56 urlConnection.setConnectTimeout(1000);
57 urlConnection.setReadTimeout(1000);
58 urlConnection.connect();
59 // Return 'success' only when the web service returns a 200.
60 if (HttpURLConnection.HTTP_OK != urlConnection.getResponseCode()) {
61 return urlConnection.getResponseMessage();
62 }
63 return IMonitorPlugin.CHECK_SUCCESS;
64 }
65 catch (Exception e) {
66 return IMonitorPlugin.CHECK_ERROR;
67 }
68 }
69 }
70 {{/code}}
71
72 Example 2: The following code shows how to query the error status of a status processing plugin.
73
74 {{code language="java"}}
75 import org.apache.commons.lang3.StringUtils;
76
77 import de.xima.fc.plugin.interfaces.IMonitorPlugin;
78 import de.xima.foobar.plugin.MyTestPlugin;
79
80 public class MyMonitor implements IMonitorPlugin {
81
82 @Override
83 public String check() throws Exception {
84 String state = MyTestPlugin.getMonitoringState();
85 if (StringUtils.isBlank(state) || StringUtils.equalsIgnoreCase(IMonitorPlugin.CHECK_SUCCESS, state)) {
86 return IMonitorPlugin.CHECK_SUCCESS;
87 } else {
88 return state;
89 }
90 }
91 }
92 {{/code}}
93
94 {{code language="java"}}
95 import java.util.ArrayList;
96 import java.util.HashMap;
97 import java.util.LinkedHashMap;
98 import java.util.List;
99 import java.util.Map;
100
101 import org.apache.commons.lang3.StringUtils;
102
103 import de.xima.fc.bl.fdv.processing.result.ProcessingResultMultiValue;
104 import de.xima.fc.interfaces.plugin.param.workflow.IPluginProcessingParams;
105 import de.xima.fc.interfaces.plugin.retval.workflow.IPluginProcessingRetVal;
106 import de.xima.fc.plugin.abstracts.AFCPlugin;
107 import de.xima.fc.plugin.config.IPluginConfigParam;
108 import de.xima.fc.plugin.config.IPluginConfigParam.EPluginParamBehavior;
109 import de.xima.fc.plugin.config.IPluginConfigParamList;
110 import de.xima.fc.plugin.exception.FCPluginException;
111 import de.xima.fc.plugin.interfaces.IMonitorPlugin;
112 import de.xima.fc.plugin.interfaces.workflow.IPluginProcessing;
113 import de.xima.fc.plugin.models.config.PluginConfigGroupItem;
114 import de.xima.fc.plugin.models.config.PluginConfigParam;
115
116
117 @SuppressWarnings("serial")
118 public class MyTestPlugin extends AFCPlugin implements IPluginProcessing, IPluginConfigParamList {
119
120 private static final String PARAM_IN_1 = "InputParameter_1";
121 private static final String PARAM_OUT = "OutputParameter";
122
123 private static String monitoringState;
124
125 public String getName() {
126 return "MyPlugin";
127 }
128
129 public void initPlugin() throws FCPluginException { }
130
131 public static String getMonitoringState() {
132 return monitoringState;
133 }
134
135 @Override
136 public IPluginProcessingRetVal execute(IPluginProcessingParams processingParams) throws FCPluginException {
137 // read input values
138 Map<String, String> pluginParams = processingParams.getParams();
139 String param1 = pluginParams.get(PARAM_IN_1);
140
141 // check and write state for monitoring
142 if (StringUtils.isBlank(param1)) {
143 monitoringState = "Param1 is empty!";
144 } else {
145 monitoringState = IMonitorPlugin.CHECK_SUCCESS;
146 }
147 // plugin processing
148 // .... do something
149
150 // write return values
151 String resultValue = "AnyResultValue";
152 return new ProcessingResultMultiValue(createResult(resultValue), true);
153 }
154
155 @Override
156 public String getDescription() {
157 return "The plugin does something important...";
158 }
159
160 @Override
161 public Map<String, IPluginConfigParam> getConfigParameter() {
162 Map<String, IPluginConfigParam> map = new LinkedHashMap<>();
163 map.put("input", new PluginConfigGroupItem("base data:"));
164 map.put(PARAM_IN_1, new PluginConfigParam(PARAM_IN_1, "This is a mandatory parameter!", true, EPluginParamBehavior.IN));
165 map.put("output", new PluginConfigGroupItem("output data:"));
166 map.put(PARAM_OUT, new PluginConfigParam(PARAM_OUT, null, false, EPluginParamBehavior.OUT));
167 return map;
168 }
169
170 private List<Map<String, String>> createResult(String result) {
171 List<Map<String, String>> resultList = new ArrayList<Map<String, String>>();
172 Map<String, String> resultMap = new HashMap<String, String>();
173 resultMap.put(PARAM_OUT, result);
174 resultList.add(resultMap);
175 return resultList;
176 }
177 }
178 {{/code}}