Design | PMD Source Code Analyzer

Rules that help you discover design issues.

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CyclomaticComplexity

Since: PMD 5.1

Priority: Medium (3)

Complexity directly affects maintenance costs is determined by the number of decision points in a method plus one for the method entry. The decision points include ‘if’, ‘while’, ‘for’, and ‘case labels’ calls.
Generally, numbers ranging from 1-4 denote low complexity, 5-7 denote moderate complexity, 8-10 denote high complexity, and 11+ is very high complexity.

This rule is defined by the following Java class: net.sourceforge.pmd.lang.plsql.rule.design.CyclomaticComplexityRule

Example(s):

-- Cyclomatic Complexity of 25 
CREATE OR REPLACE PACKAGE BODY pkg_pmd_working_sequence  AS
1 PROCEDURE ty_logger  IS BEGIN
2        IF true
         THEN
              DBMS_OUTPUT.PUT_LINE('IF/THEN l_Integer='||l_integer);
3        IF true
         THEN
              DBMS_OUTPUT.PUT_LINE('IF/THEN l_Integer='||l_integer);
4            IF true
             THEN
                  DBMS_OUTPUT.PUT_LINE('IF/THEN l_Integer='||l_integer);
5            ELSIF false
             THEN
                DBMS_OUTPUT.PUT_LINE('ELSIF l_Integer='||l_integer);
             ELSE
                DBMS_OUTPUT.PUT_LINE('ELSIF l_Integer='||l_integer);
             END IF;
6        ELSIF false
         THEN
            DBMS_OUTPUT.PUT_LINE('ELSIF l_Integer='||l_integer);
7            IF true
             THEN
                  DBMS_OUTPUT.PUT_LINE('IF/THEN l_Integer='||l_integer);
8            ELSIF false
             THEN
                DBMS_OUTPUT.PUT_LINE('ELSIF l_Integer='||l_integer);
             ELSE
                DBMS_OUTPUT.PUT_LINE('ELSIF l_Integer='||l_integer);
             END IF;
         ELSE
            DBMS_OUTPUT.PUT_LINE('ELSIF l_Integer='||l_integer);
9            IF true
             THEN
                  DBMS_OUTPUT.PUT_LINE('IF/THEN l_Integer='||l_integer);
10           ELSIF false
             THEN
                DBMS_OUTPUT.PUT_LINE('ELSIF l_Integer='||l_integer);
             ELSE
                DBMS_OUTPUT.PUT_LINE('ELSIF l_Integer='||l_integer);
             END IF;
         END IF;
11         ELSIF false
         THEN
            DBMS_OUTPUT.PUT_LINE('ELSIF l_Integer='||l_integer);
12       IF true
         THEN
              DBMS_OUTPUT.PUT_LINE('IF/THEN l_Integer='||l_integer);
13           IF true
             THEN
                  DBMS_OUTPUT.PUT_LINE('IF/THEN l_Integer='||l_integer);
14           ELSIF false
             THEN
                DBMS_OUTPUT.PUT_LINE('ELSIF l_Integer='||l_integer);
             ELSE
                DBMS_OUTPUT.PUT_LINE('ELSIF l_Integer='||l_integer);
             END IF;
15       ELSIF false
         THEN
16           IF true
             THEN
                  DBMS_OUTPUT.PUT_LINE('IF/THEN l_Integer='||l_integer);
17           ELSIF false
             THEN
                DBMS_OUTPUT.PUT_LINE('ELSIF l_Integer='||l_integer);
             ELSE
                DBMS_OUTPUT.PUT_LINE('ELSIF l_Integer='||l_integer);
             END IF;
             DBMS_OUTPUT.PUT_LINE('ELSIF l_Integer='||l_integer);
         ELSE
             DBMS_OUTPUT.PUT_LINE('ELSIF l_Integer='||l_integer);
         END IF;
     ELSE
        DBMS_OUTPUT.PUT_LINE('ELSIF l_Integer='||l_integer);
18       IF true
         THEN
              DBMS_OUTPUT.PUT_LINE('IF/THEN l_Integer='||l_integer);
19           IF true
             THEN
                  DBMS_OUTPUT.PUT_LINE('IF/THEN l_Integer='||l_integer);
20           ELSIF false
             THEN
                DBMS_OUTPUT.PUT_LINE('ELSIF l_Integer='||l_integer);
             ELSE
                DBMS_OUTPUT.PUT_LINE('ELSIF l_Integer='||l_integer);
             END IF;
21       ELSIF false
         THEN
            DBMS_OUTPUT.PUT_LINE('ELSIF l_Integer='||l_integer);
22           IF true
             THEN
                DBMS_OUTPUT.PUT_LINE('IF/THEN l_Integer='||l_integer);
23           ELSIF false
             THEN
                DBMS_OUTPUT.PUT_LINE('ELSIF l_Integer='||l_integer);
             ELSE
                DBMS_OUTPUT.PUT_LINE('ELSIF l_Integer='||l_integer);
             END IF;
             ELSE
             DBMS_OUTPUT.PUT_LINE('ELSIF l_Integer='||l_integer);
24           IF true
             THEN
                  DBMS_OUTPUT.PUT_LINE('IF/THEN l_Integer='||l_integer);
25           ELSIF false
             THEN
                DBMS_OUTPUT.PUT_LINE('ELSIF l_Integer='||l_integer);
             ELSE
                DBMS_OUTPUT.PUT_LINE('ELSIF l_Integer='||l_integer);
             END IF;
         END IF;
     END IF;
END;

END;

This rule has the following properties:

Name	Default Value	Description	Multivalued
showMethodsComplexity	true	Add method average violations to the report	no
showClassesComplexity	true	Add class average violations to the report	no
reportLevel	10	Cyclomatic Complexity reporting threshold	no

Use this rule by referencing it:

<rule ref="category/plsql/design.xml/CyclomaticComplexity" />

ExcessiveMethodLength

Since: PMD 5.1

Priority: Medium (3)

When methods are excessively long this usually indicates that the method is doing more than its name/signature might suggest. They also become challenging for others to digest since excessive scrolling causes readers to lose focus. Try to reduce the method length by creating helper methods and removing any copy/pasted code.

This rule is defined by the following Java class: net.sourceforge.pmd.lang.plsql.rule.design.ExcessiveMethodLengthRule

Example(s):

CREATE OR REPLACE
PROCEDURE doSomething BEGIN
    DBMS_OUTPUT.PUT_LINE("Hello world!");
    DBMS_OUTPUT.PUT_LINE("Hello world!");
        -- 98 copies omitted for brevity.
END;

This rule has the following properties:

Name	Description	Multivalued
topscore	Top score value	no
minimum	Minimum reporting threshold	no
sigma	Sigma value	no

Use this rule by referencing it:

<rule ref="category/plsql/design.xml/ExcessiveMethodLength" />

ExcessiveObjectLength

Since: PMD 5.1

Priority: Medium (3)

Excessive object line lengths are usually indications that the object may be burdened with excessive responsibilities that could be provided by other objects. In breaking these methods apart the code becomes more managable and ripe for reuse.

This rule is defined by the following Java class: net.sourceforge.pmd.lang.plsql.rule.design.ExcessiveObjectLengthRule

Example(s):

CREATE OR REPLACE
PACKAGE BODY Foo AS
    PROCEDURE bar1 IS BEGIN
    -- 1000 lines of code
    END bar1;
    PROCEDURE bar2 IS BEGIN
    -- 1000 lines of code
    END bar2;
    PROCEDURE bar3 IS BEGIN
    -- 1000 lines of code
    END bar3;


    PROCEDURE barN IS BEGIN
    -- 1000 lines of code
    END barn;
END;

This rule has the following properties:

Name	Description	Multivalued
topscore	Top score value	no
minimum	Minimum reporting threshold	no
sigma	Sigma value	no

Use this rule by referencing it:

<rule ref="category/plsql/design.xml/ExcessiveObjectLength" />

ExcessivePackageBodyLength

Since: PMD 5.1

Priority: Medium (3)

Excessive class file lengths are usually indications that the class may be burdened with excessive responsibilities that could be provided by external classes or functions. In breaking these methods apart the code becomes more managable and ripe for reuse.

This rule is defined by the following Java class: net.sourceforge.pmd.lang.plsql.rule.design.ExcessivePackageBodyLengthRule

Example(s):

CREATE OR REPLACE
PACKAGE BODY Foo AS
    PROCEDURE bar1 IS BEGIN
    -- 1000 lines of code
    END bar1;
    PROCEDURE bar2 IS BEGIN
    -- 1000 lines of code
    END bar2;
    PROCEDURE bar3 IS BEGIN
    -- 1000 lines of code
    END bar3;


    PROCEDURE barN IS BEGIN
    -- 1000 lines of code
    END barn;
END;

This rule has the following properties:

Name	Description	Multivalued
topscore	Top score value	no
minimum	Minimum reporting threshold	no
sigma	Sigma value	no

Use this rule by referencing it:

<rule ref="category/plsql/design.xml/ExcessivePackageBodyLength" />

ExcessivePackageSpecificationLength

Since: PMD 5.1

Priority: Medium (3)

This rule is defined by the following Java class: net.sourceforge.pmd.lang.plsql.rule.design.ExcessivePackageSpecificationLengthRule

Example(s):

CREATE OR REPLACE
PACKAGE Foo AS
    PROCEDURE bar1;
    PROCEDURE bar2;
    PROCEDURE bar3;

    ...

    PROCEDURE barN;
END;

This rule has the following properties:

Name	Description	Multivalued
topscore	Top score value	no
minimum	Minimum reporting threshold	no
sigma	Sigma value	no

Use this rule by referencing it:

<rule ref="category/plsql/design.xml/ExcessivePackageSpecificationLength" />

ExcessiveParameterList

Since: PMD 5.1

Priority: Medium (3)

Methods with numerous parameters are a challenge to maintain, especially if most of them share the same datatype. These situations usually denote the need for new objects to wrap the numerous parameters.

This rule is defined by the following Java class: net.sourceforge.pmd.lang.plsql.rule.design.ExcessiveParameterListRule

Example(s):

CREATE OR REPLACE
PROCEDURE addPerson(        -- too many arguments liable to be mixed up
    birthYear pls_integer, birthMonth pls_integer, birthDate pls_integer, height pls_integer, weight pls_integer, ssn pls_integer) {

    . . . .
END ADDPERSON;

CREATE OR REPLACE
PROCEDURE addPerson(        -- preferred approach
    birthdate DATE, measurements BodyMeasurements , ssn INTEGER) BEGIN

    . . . .
END;

This rule has the following properties:

Name	Description	Multivalued
topscore	Top score value	no
minimum	Minimum reporting threshold	no
sigma	Sigma value	no

Use this rule by referencing it:

<rule ref="category/plsql/design.xml/ExcessiveParameterList" />

ExcessiveTypeLength

Since: PMD 5.1

Priority: Medium (3)

This rule is defined by the following Java class: net.sourceforge.pmd.lang.plsql.rule.design.ExcessiveTypeLengthRule

Example(s):

CREATE OR REPLACE
TYPE BODY Foo AS
    MEMBER PROCEDURE bar1 IS BEGIN
    -- 1000 lines of code
    END bar1;
    MEMBER PROCEDURE bar2 IS BEGIN
    -- 1000 lines of code
    END bar2;
    MEMBER PROCEDURE bar3 IS BEGIN
    -- 1000 lines of code
    END bar3;


    MEMBER PROCEDURE barN IS BEGIN
    -- 1000 lines of code
    END barn;
END;

This rule has the following properties:

Name	Description	Multivalued
topscore	Top score value	no
minimum	Minimum reporting threshold	no
sigma	Sigma value	no

Use this rule by referencing it:

<rule ref="category/plsql/design.xml/ExcessiveTypeLength" />

NcssMethodCount

Since: PMD 5.1

Priority: Medium (3)

This rule uses the NCSS (Non-Commenting Source Statements) algorithm to determine the number of lines of code for a given method. NCSS ignores comments, and counts actual statements. Using this algorithm, lines of code that are split are counted as one.

This rule is defined by the following Java class: net.sourceforge.pmd.lang.plsql.rule.design.NcssMethodCountRule

Example(s):

CREATE OR REPLACE PACKAGE BODY AS
 FUNCTION methd RETURN INTEGER IS
 BEGIN
   RETURN 1;;
 END;
END;

This rule has the following properties:

Name	Description	Multivalued
topscore	Top score value	no
minimum	Minimum reporting threshold	no
sigma	Sigma value	no

Use this rule by referencing it:

<rule ref="category/plsql/design.xml/NcssMethodCount" />

NcssObjectCount

Since: PMD 5.1

Priority: Medium (3)

This rule uses the NCSS (Non-Commenting Source Statements) algorithm to determine the number of lines of code for a given Oracle object. NCSS ignores comments, and counts actual statements. Using this algorithm, lines of code that are split are counted as one.

This rule is defined by the following Java class: net.sourceforge.pmd.lang.plsql.rule.design.NcssObjectCountRule

Example(s):

CREATE OR REPLACE PACKAGE pkg_
 PROCEDURE Foo IS
 BEGIN
 --this class only has 6 NCSS lines
     super();
     super();
 END;
}

This rule has the following properties:

Name	Description	Multivalued
topscore	Top score value	no
minimum	Minimum reporting threshold	no
sigma	Sigma value	no

Use this rule by referencing it:

<rule ref="category/plsql/design.xml/NcssObjectCount" />

NPathComplexity

Since: PMD 5.1

Priority: Medium (3)

The NPath complexity of a method is the number of acyclic execution paths through that method. A threshold of 200 is generally considered the point where measures should be taken to reduce complexity and increase readability.

This rule is defined by the following Java class: net.sourceforge.pmd.lang.plsql.rule.design.NPathComplexityRule

Example(s):

CREATE OR REPLACE
PROCEDURE bar AS BEGIN  -- this is something more complex than it needs to be,
    if (y) THEN -- it should be broken down into smaller methods or functions
        for j IN 0 .. j-1 LOOP
            if (j > r) THEN
                doSomething;
                while (f < 5 ) LOOP
                    anotherThing;
                    f := f - 27;
                    END LOOP;
            else
                tryThis();
            END IF;
        END LOOP;
    END IF;
    if ( r - n > 45) THEN
        while (doMagic) LOOP
            findRabbits;
        END LOOP;
    END IF;
    BEGIN
        doSomethingDangerous();
    EXCEPTION WHEN FooException THEN
        makeAmends;
        BEGIN
            dontDoItAgain;
        EXCEPTION
        WHEN OTHERS THEN
            log_problem;
        END;
    END;
END;

This rule has the following properties:

Name	Description	Multivalued
topscore	Top score value	no
minimum	Minimum reporting threshold	no
sigma	Sigma value	no

Use this rule by referencing it:

<rule ref="category/plsql/design.xml/NPathComplexity" />

TooManyFields

Since: PMD 5.1

Priority: Medium (3)

Classes that have too many fields can become unwieldy and could be redesigned to have fewer fields, possibly through grouping related fields in new objects. For example, a class with individual city/state/zip fields could park them within a single Address field.

This rule is defined by the following Java class: net.sourceforge.pmd.lang.plsql.rule.design.TooManyFieldsRule

Example(s):

CREATE OR REPLACE PACKAGE pkg_too_many_fields AS
    C_CHAR_A CONSTANT CHAR(1 CHAR) := 'A';
    C_CHAR_B CONSTANT CHAR(1 CHAR) := 'B';
    ...
    C_CHAR_Z CONSTANT CHAR(1 CHAR) := 'Z';
END pkg_too_many_fields;

This rule has the following properties:

Name	Default Value	Description	Multivalued
maxfields	15	Max allowable fields	no

Use this rule by referencing it:

<rule ref="category/plsql/design.xml/TooManyFields" />

TooManyMethods

Since: PMD 5.1

Priority: Medium (3)

A package or type with too many methods is probably a good suspect for refactoring, in order to reduce its complexity and find a way to have more fine grained objects.

This rule is defined by the following XPath expression:

//node()
     [ (
        local-name(.) = 'PackageSpecification'
        or
        local-name(.) = 'TypeSpecification'
       )
       and 
      (
      count(/descendant::ProgramUnit[
                                         not (
                                                starts-with(@Image,'get')
                                                or
                                                starts-with(@Image,'set')
                                                or
                                                starts-with(@Image,'is')
                                            )
                                       ]
           )
      +
      count(/descendant::TypeMethod[
                                         not (
                                                starts-with(@Image,'get')
                                                or
                                                starts-with(@Image,'set')
                                                or
                                                starts-with(@Image,'is')
                                            )
                                       ]
           )
      ) > $maxmethods
     ]

This rule has the following properties:

Name	Default Value	Description	Multivalued
maxmethods	1	The method count reporting threshold	no

Use this rule by referencing it:

<rule ref="category/plsql/design.xml/TooManyMethods" />