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1   /**
2    * Logback: the reliable, generic, fast and flexible logging framework.
3    * Copyright (C) 1999-2015, QOS.ch. All rights reserved.
4    *
5    * This program and the accompanying materials are dual-licensed under
6    * either the terms of the Eclipse Public License v1.0 as published by
7    * the Eclipse Foundation
8    *
9    *   or (per the licensee's choosing)
10   *
11   * under the terms of the GNU Lesser General Public License version 2.1
12   * as published by the Free Software Foundation.
13   */
14  package ch.qos.logback.core.joran.action;
15  
16  import ch.qos.logback.core.joran.action.ActionUtil.Scope;
17  import ch.qos.logback.core.joran.spi.InterpretationContext;
18  import ch.qos.logback.core.joran.spi.ActionException;
19  import ch.qos.logback.core.spi.LifeCycle;
20  import ch.qos.logback.core.util.OptionHelper;
21  import ch.qos.logback.core.spi.PropertyDefiner;
22  import org.xml.sax.Attributes;
23  
24  /**
25   * Instantiate class for define property value. Get future property name and
26   * property definer class from attributes. Some property definer properties
27   * could be used. After defining put new property to context.
28   * 
29   * @author Aleksey Didik
30   */
31  public class DefinePropertyAction extends Action {
32  
33      String scopeStr;
34      Scope scope;
35      String propertyName;
36      PropertyDefiner definer;
37      boolean inError;
38  
39      public void begin(InterpretationContext ec, String localName, Attributes attributes) throws ActionException {
40          // reset variables
41          scopeStr = null;
42          scope = null;
43          propertyName = null;
44          definer = null;
45          inError = false;
46  
47          // read future property name
48          propertyName = attributes.getValue(NAME_ATTRIBUTE);
49          scopeStr = attributes.getValue(SCOPE_ATTRIBUTE);
50  
51          scope = ActionUtil.stringToScope(scopeStr);
52          if (OptionHelper.isEmpty(propertyName)) {
53              addError("Missing property name for property definer. Near [" + localName + "] line " + getLineNumber(ec));
54              inError = true;
55              return;
56          }
57  
58          // read property definer class name
59          String className = attributes.getValue(CLASS_ATTRIBUTE);
60          if (OptionHelper.isEmpty(className)) {
61              addError("Missing class name for property definer. Near [" + localName + "] line " + getLineNumber(ec));
62              inError = true;
63              return;
64          }
65  
66          // try to instantiate property definer
67          try {
68              addInfo("About to instantiate property definer of type [" + className + "]");
69              definer = (PropertyDefiner) OptionHelper.instantiateByClassName(className, PropertyDefiner.class, context);
70              definer.setContext(context);
71              if (definer instanceof LifeCycle) {
72                  ((LifeCycle) definer).start();
73              }
74              ec.pushObject(definer);
75          } catch (Exception oops) {
76              inError = true;
77              addError("Could not create an PropertyDefiner of type [" + className + "].", oops);
78              throw new ActionException(oops);
79          }
80      }
81  
82      /**
83       * Now property definer is initialized by all properties and we can put
84       * property value to context
85       */
86      public void end(InterpretationContext ec, String name) {
87          if (inError) {
88              return;
89          }
90  
91          Object o = ec.peekObject();
92  
93          if (o != definer) {
94              addWarn("The object at the of the stack is not the property definer for property named [" + propertyName + "] pushed earlier.");
95          } else {
96              addInfo("Popping property definer for property named [" + propertyName + "] from the object stack");
97              ec.popObject();
98              // let's put defined property and value to context but only if it is
99              // not null
100             String propertyValue = definer.getPropertyValue();
101             if (propertyValue != null) {
102                 ActionUtil.setProperty(ec, propertyName, propertyValue, scope);
103             }
104         }
105     }
106 }