org.jfree.report.function: public class: TotalItemMaxFunction

org.jfree.report.function
public class: TotalItemMaxFunction [javadoc | source]

java.lang.Object
   org.jfree.report.function.AbstractExpression
      org.jfree.report.function.AbstractFunction
         org.jfree.report.function.TotalItemMaxFunction

All Implemented Interfaces:
Function, Expression, Serializable

A report function that pre-computes the largest item in a group. The Items must be mutually comparable among each other or the function will fail. Comparing dates with strings will not work.

Like all Total-Functions, this function produces a precomputed grand total. The function's result is precomputed once and will not change later. Printing the result of this function in a group header returns the same value as printed in the group-footer.

A group can be defined using the property "group". If the group property is not set, the function will process the whole report.

author: Thomas - Morgner

Constructor:
public TotalItemMaxFunction() { results = new HashMap(); } Default constructor.

Constructor:

 public TotalItemMaxFunction() {
       
    results = new HashMap();
}

Default constructor.

Method from org.jfree.report.function.TotalItemMaxFunction Summary:
getField, getGroup, getInstance, getValue, groupStarted, itemsAdvanced, reportInitialized, setField, setGroup

Methods from org.jfree.report.function.AbstractFunction:
groupFinished, groupStarted, itemsAdvanced, itemsFinished, itemsStarted, reportDone, reportFinished, reportInitialized, reportStarted

Methods from org.jfree.report.function.AbstractExpression:
clone, getDataRow, getDependencyLevel, getInstance, getName, getReportConfiguration, getResourceBundleFactory, getRuntime, isActive, isDeepTraversing, isPreserve, setActive, setDependencyLevel, setName, setPreserve, setRuntime

Methods from java.lang.Object:
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method from org.jfree.report.function.TotalItemMaxFunction Detail:
public String getField() { return field; } Returns the field used by the function. The field name corresponds to a column name in the report's data-row.
public String getGroup() { return group; } Returns the name of the group for which the minimum should be computed.
public Expression getInstance() { final TotalItemMaxFunction function = (TotalItemMaxFunction) super.getInstance(); function.results = new HashMap(); return function; } Return a completly separated copy of this function. The copy does no longer share any changeable objects with the original function.
public Object getValue() { return max; } Returns the computed maximum value.
public void groupStarted(ReportEvent event) { if (FunctionUtilities.isDefinedGroup(getGroup(), event) == false) { // wrong group ... return; } groupStateKey = event.getState().getProcessKey(); if (FunctionUtilities.isDefinedPrepareRunLevel(this, event)) { this.max = null; results.put(globalStateKey, max); results.put(groupStateKey, max); } else { // Activate the current group, which was filled in the prepare run. max = (Integer) results.get(groupStateKey); } } Receives notification that a group has started.
public void itemsAdvanced(ReportEvent event) { if (FunctionUtilities.isDefinedPrepareRunLevel(this, event) == false) { return; } final Object fieldValue = event.getDataRow().get(getField()); if (fieldValue instanceof Comparable == false) { return; } try { final Comparable compare = (Comparable) fieldValue; if (max == null) { max = compare; } else if (max.compareTo(compare) < 0) { max = compare; } } catch (Exception e) { TotalItemMaxFunction.logger.error("TotalItemMaxFunction.advanceItems(): problem comparing values."); } results.put(globalStateKey, max); if (groupStateKey != null) { results.put(groupStateKey, max); } } Receives notification that a row of data is being processed.
public void reportInitialized(ReportEvent event) { globalStateKey = event.getState().getProcessKey(); if (FunctionUtilities.isDefinedPrepareRunLevel(this, event)) { results.clear(); this.max = null; results.put(globalStateKey, null); } else { this.max = (Comparable) results.get(globalStateKey); } } Receives notification that the report has started.
public void setField(String field) { this.field = field; } Sets the field name for the function. The field name corresponds to a column name in the report's data-row.
public void setGroup(String group) { this.group = group; } Defines the name of the group to be totalled. If the name is null, the minimum for the whole report is computed.

Method from org.jfree.report.function.TotalItemMaxFunction Detail:

 public String getField() {
    return field;
}

Returns the field used by the function. The field name corresponds to a column name in the report's data-row.

 public String getGroup() {
    return group;
}

Returns the name of the group for which the minimum should be computed.

 public Expression getInstance() {
    final TotalItemMaxFunction function = (TotalItemMaxFunction) super.getInstance();
    function.results = new HashMap();
    return function;
}

Return a completly separated copy of this function. The copy does no longer share any changeable objects with the original function.

 public Object getValue() {
    return max;
}

Returns the computed maximum value.

 public  void groupStarted(ReportEvent event) {
    if (FunctionUtilities.isDefinedGroup(getGroup(), event) == false)
    {
      // wrong group ...
      return;
    }
    groupStateKey = event.getState().getProcessKey();
    if (FunctionUtilities.isDefinedPrepareRunLevel(this, event))
    {
      this.max = null;
      results.put(globalStateKey, max);
      results.put(groupStateKey, max);
    }
    else
    {
      // Activate the current group, which was filled in the prepare run.
      max = (Integer) results.get(groupStateKey);
    }
}

Receives notification that a group has started.

 public  void itemsAdvanced(ReportEvent event) {
    if (FunctionUtilities.isDefinedPrepareRunLevel(this, event) == false)
    {
      return;
    }
    final Object fieldValue = event.getDataRow().get(getField());
    if (fieldValue instanceof Comparable == false)
    {
      return;
    }
    try
    {
      final Comparable compare = (Comparable) fieldValue;
      if (max == null)
      {
        max = compare;
      }
      else if (max.compareTo(compare) <  0)
      {
        max = compare;
      }
    }
    catch (Exception e)
    {
      TotalItemMaxFunction.logger.error("TotalItemMaxFunction.advanceItems(): problem comparing values.");
    }
    results.put(globalStateKey, max);
    if (groupStateKey != null)
    {
      results.put(groupStateKey, max);
    }
}

Receives notification that a row of data is being processed.

 public  void reportInitialized(ReportEvent event) {
    globalStateKey = event.getState().getProcessKey();
    if (FunctionUtilities.isDefinedPrepareRunLevel(this, event))
    {
      results.clear();
      this.max = null;
      results.put(globalStateKey, null);
    }
    else
    {
      this.max = (Comparable) results.get(globalStateKey);
    }
}

Receives notification that the report has started.

 public  void setField(String field) {
    this.field = field;
}

Sets the field name for the function. The field name corresponds to a column name in the report's data-row.

 public  void setGroup(String group) {
    this.group = group;
}

Defines the name of the group to be totalled. If the name is null, the minimum for the whole report is computed.