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1. Adding the commons-lang dependency to your project.xml
   1. Add the following to the dependencies block of your project.xml file to include the commons-lang:

      Code Block
      xml xml
      <dependency> <groupId>commons-lang</groupId> <artifactId>commons-lang</artifactId> <version>${sakai.commons.lang.version}</version> </dependency>

      • The commons-lang package is included in shared/lib by Sakai itself so you do not need to package it in your tool war file (hence there is no <war.bundle>true</war.bundle>)
      • Do not specify a version, use the version that Sakai is placing in the shared/lib by using the property (sakai.commons.lang.version) as shown above
2. Using the lang functions in your object or object implementation code - Apache commons-lang API
   Note: All code below should go in the object or object implementation
   1. Add the required imports

      Code Block
      import org.apache.commons.lang.builder.CompareToBuilder; import org.apache.commons.lang.builder.EqualsBuilder; import org.apache.commons.lang.builder.HashCodeBuilder; import org.apache.commons.lang.builder.ToStringBuilder;

   2. Create an equals function using the EqualsBuilder

      Code Block
      public boolean equals(Object obj) { if (null == obj) return false; if (obj instanceof org.sakaiproject.tool.mytool.MyObject == false) { return false; } if (this == obj) { return true; } org.sakaiproject.tool.mytool.MyObject castObj = (org.sakaiproject.tool.mytool.MyObject) obj; return new EqualsBuilder() .append(this.getId(), castObj.getId()) .isEquals(); }

      • This simple example only compares the id values of the 2 objects, however you could compare many values by doing something like this:

        Code Block
        return new EqualsBuilder() .append(this.field1, castObj.getField1()) .append(this.field2, castObj.getField2()) .append(this.field3, castObj.getField3()) .isEquals();

   3. Create a hashCode function using the HashCodeBuilder

      Code Block
      public int hashCode() { // pick 2 hard-coded, odd, >0 ints as args return new HashCodeBuilder(1, 31) .append(this.id) .toHashCode(); }

      • Like the previous example, this only uses the id for creating the hashCode but you can easy easily append more properties
   4. Create a compareTo function using the CompareToBuilder

      Code Block
      public int compareTo(Object obj) { org.sakaiproject.tool.mytool.MyObject castObj = (org.sakaiproject.tool.mytool.MyObject) obj; return new CompareToBuilder() .append(this.getId(), castObj.getId()) .toComparison(); }

      • Like the previous examples, this only uses the id for comparison but you can easy easily append more properties
   5. Create a toString function using the ToStringBuilder

      Code Block
      public String toString() { return new ToStringBuilder(this) .append(this.id) .toString(); }

      • Like the previous examples, this only uses the id for comparison string generation but you can easy easily append more properties
3. Your object should now be comparable to objects of the same type that have the same data
   • A sample of an object which demostrates use of the commons-lang builders: TaskImpl.java