cvs commit: logging-log4j/examples/src/joran/implicit PrintMe.java PrintMeImplicitAction.java NOPAction.java implicit1.xml

[ce...@apache.org]

ceki        2004/04/10 06:47:58

  Added:       examples/src/joran/implicit PrintMe.java
                        PrintMeImplicitAction.java NOPAction.java
                        implicit1.xml
  Log:
  
  Example of a an implicit action and its usage. (A rather contrived axample)
  
  Revision  Changes    Path
  1.1                  logging-log4j/examples/src/joran/implicit/PrintMe.java
  
  Index: PrintMe.java
  ===================================================================
  /*
   * Copyright 1999,2004 The Apache Software Foundation.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package joran.implicit;
  
  import joran.calculator.ComputationAction2;
  
  import org.apache.joran.Interpreter;
  import org.apache.joran.Pattern;
  import org.apache.joran.RuleStore;
  import org.apache.joran.action.NewRuleAction;
  import org.apache.joran.helper.SimpleRuleStore;
  
  import java.util.List;
  
  import javax.xml.parsers.SAXParser;
  import javax.xml.parsers.SAXParserFactory;
  
  
  /**
   * This example illustrates the usage of NewRuleAction which allows the Joran
   * interpreter to learn new rules on the fly from the XML file being
   * interpreted.
   *
   * This example relies heavily on the code from the joran.calculator package.
   *
   * @author Ceki Güulcü
   */
  public class PrintMe {
    
    
    public static void main(String[] args) throws Exception {
      // Uncomment the following line in order to enable log statements generated
      // from joran itself.
      
      // org.apache.log4j.BasicConfigurator.configure();
      
      RuleStore ruleStore = new SimpleRuleStore();
  
      // we start with the rule for the top-most (root) element
      ruleStore.addRule(new Pattern("*/foo"), new NOPAction());
  
  
      // Create a new Joran Interpreter and hand it our simple rule store.
      Interpreter ji = new Interpreter(ruleStore);
  
      // 
      // Add an implicit action.
      // 
      ji.addImplcitAction(new PrintMeImplicitAction());
      
      // Create a SAX parser
      SAXParserFactory spf = SAXParserFactory.newInstance();
      SAXParser saxParser = spf.newSAXParser();
  
      // Parse the file given as the application's first argument and
      // set the SAX ContentHandler to the Joran Interpreter we just created.
      saxParser.parse(args[0], ji);
  
      // The file has been parsed and interpreted. We now errors if any.
      List errorList = ji.getExecutionContext().getErrorList();
  
      if (errorList.size() > 0) {
        System.out.println("The following errors occured:");
  
        for (int i = 0; i < errorList.size(); i++) {
          System.out.println("\t" + errorList.get(i));
        }
      }
    }
  }
  
  
  
  1.1                  logging-log4j/examples/src/joran/implicit/PrintMeImplicitAction.java
  
  Index: PrintMeImplicitAction.java
  ===================================================================
  /*
   * Copyright 1999,2004 The Apache Software Foundation.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package joran.implicit;
  
  import org.apache.joran.ExecutionContext;
  import org.apache.joran.Pattern;
  import org.apache.joran.action.ImplicitAction;
  
  import org.xml.sax.Attributes;
  
  
  
  /**
   *
   * A rather trivial implicit action which is applicable as soon as an
   * element has a printme attribute set to true. 
   *
   * @author Ceki G&uuml;lc&uuml;
   */
  public class PrintMeImplicitAction extends ImplicitAction {
    
    public boolean isApplicable(
      Pattern pattern, Attributes attributes, ExecutionContext ec) {
      String printmeStr = attributes.getValue("printme");
  
      return Boolean.valueOf(printmeStr).booleanValue();
    }
  
    public void begin(ExecutionContext ec, String name, Attributes attributes) {
      System.out.println("Element <"+name+"> asked to be printed.");
     }
  
   
    public void end(ExecutionContext ec, String name) {
    }
  }
  
  
  
  1.1                  logging-log4j/examples/src/joran/implicit/NOPAction.java
  
  Index: NOPAction.java
  ===================================================================
  /*
   * Copyright 1999,2004 The Apache Software Foundation.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package joran.implicit;
  
  import org.apache.joran.ExecutionContext;
  import org.apache.joran.action.Action;
  
  import org.xml.sax.Attributes;
  
  
  
  /**
   * No operation (NOP) action that does strictly nothing. 
   *  
   * @author Ceki G&uuml;lc&uuml;
   */
  public class NOPAction extends Action {
    
    public void begin(ExecutionContext ec, String name, Attributes attributes) {
    }
  
  
    public void end(ExecutionContext ec, String name) {
    }
  }
  
  
  
  1.1                  logging-log4j/examples/src/joran/implicit/implicit1.xml
  
  Index: implicit1.xml
  ===================================================================
  <?xml version="1.0" encoding="UTF-8" ?>
  <!DOCTYPE foo>
  
  <foo>
  
    <!-- These elements will print due to the implcit rule -->
    <xyz printme="true">
      <abc printme="true"/>
    </xyz>
  
    <!-- This element has no associated rule and no implicit rule 
         applies for it because the printme attribute is not set. -->  
    <xyz/>
  
    
    
    <!-- This element will not be printed even if its printme 
         attribute  is set because implicit rules are invoked only 
         if no explicit rule matches the element. The */foo rule
         mathches the following element.
         --> 
    <foo printme="true"/>
  
  </foo>
  
  

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