if (instance == null) { instance = new HeaderItemDNDManager(); } return instance;
if (serviceInstance == null) { // load instance of service serviceInstance = loadInstance(implementationName); } return serviceInstance;
Clone fragments detected by clone detection tool
File path: /columba-1.4-src/mail/src/main/java/org/columba/mail/gui/contact/list/HeaderItemDNDManager.java File path: /columba-1.4-src/core/src/main/java/org/columba/core/facade/ServiceFacadeRegistry.java
Method name: HeaderItemDNDManager getInstance() Method name: Object getServiceInstance()
Number of AST nodes: 3 Number of AST nodes: 3
1
if (instance == null) {
1
if (serviceInstance == null) {
2
            instance = new HeaderItemDNDManager();
3
        }
4
        return i
2
				// load instance of service
3
				serviceInstance = loadInstance(implementationName);
4
			}
5
nstance;
5
			return serviceInstance;
Summary
Number of common nesting structure subtrees1
Number of refactorable cases0
Number of non-refactorable cases1
Time elapsed for finding largest common nesting structure subtrees (ms)0.1
Clones locationClones are in different classes
Number of node comparisons5
  1. {Non-refactorable}
    Mapping Summary
    Number of mapped statements1
    Number of unmapped statements in the first code fragment2
    Number of unmapped statements in the second code fragment2
    Time elapsed for statement mapping (ms)0.4
    Clone typeType 2
    Mapped Statements
    ID Statement ID Statement
    1
    if (instance == null)
    1
    if (instance == null)
    1
    if (serviceInstance == null)
    Differences
    Expression1Expression2Difference
    instanceserviceInstanceVARIABLE_NAME_MISMATCH
    org.columba.mail.gui.contact.list.HeaderItemDNDManagerjava.lang.ObjectVARIABLE_TYPE_MISMATCH
    Preondition Violations
    Type org.columba.mail.gui.contact.list.HeaderItemDNDManager of variable instance does not match with type java.lang.Object of variable serviceInstance
    • Make classes org.columba.mail.gui.contact.list.HeaderItemDNDManager and java.lang.Object extend a common superclass
    1
    if (serviceInstance == null)
                                                                                                            
    2
    serviceInstance = loadInstance(implementationName);
    Preondition Violations
    Unmatched statement serviceInstance=loadInstance(implementationName); cannot be moved before the extracted code, because it has control dependencies from statements that will be extracted
    2
    serviceInstance = loadInstance(implementationName);
    2
    instance = new HeaderItemDNDManager();
    2
    instance = new HeaderItemDNDManager();
    Preondition Violations
    Unmatched statement instance=new HeaderItemDNDManager(); cannot be moved before the extracted code, because it has control dependencies from statements that will be extracted
                                                                                  
                                                        
    3
    return serviceInstance;
    Preondition Violations
    Unmatched return serviceInstance;
    3
    return serviceInstance;
    3
    return instance;
    3
    return instance;
    Preondition Violations
    Unmatched return instance;
                                          
    Precondition Violations (6)
    Row Violation
    1Type org.columba.mail.gui.contact.list.HeaderItemDNDManager of variable instance does not match with type java.lang.Object of variable serviceInstance
    2Unmatched statement serviceInstance=loadInstance(implementationName); cannot be moved before the extracted code, because it has control dependencies from statements that will be extracted
    3Unmatched statement instance=new HeaderItemDNDManager(); cannot be moved before the extracted code, because it has control dependencies from statements that will be extracted
    4Unmatched return serviceInstance;
    5Unmatched return instance;
    6The refactoring of the clones is infeasible, because the number of macthed statements is equal to zero