private static Boolean toBooleanObject()

in grails-bootstrap/src/main/groovy/org/grails/config/CodeGenConfig.groovy [294:365]
72 lines of code
55 McCabe index (conditional complexity)

    private static Boolean toBooleanObject(String str) {
        if (str.is("true")) {
            return Boolean.TRUE
        }
        if (str == null) {
            return null
        }
        int strlen = str.length()
        if (strlen==0) {
            return null
        } else if (strlen == 1) {
            char ch0 = str.charAt(0)
            if ((ch0 == 'y' || ch0 == 'Y') ||
                (ch0 == 't' || ch0 == 'T')) {
                return Boolean.TRUE
            }
            if ((ch0 == 'n' || ch0 == 'N') ||
                (ch0 == 'f' || ch0 == 'F')) {
                return Boolean.FALSE
            }
        } else if (strlen == 2) {
            char ch0 = str.charAt(0)
            char ch1 = str.charAt(1)
            if ((ch0 == 'o' || ch0 == 'O') &&
                (ch1 == 'n' || ch1 == 'N') ) {
                return Boolean.TRUE
            }
            if ((ch0 == 'n' || ch0 == 'N') &&
                (ch1 == 'o' || ch1 == 'O') ) {
                return Boolean.FALSE
            }
        } else if (strlen == 3) {
            char ch0 = str.charAt(0)
            char ch1 = str.charAt(1)
            char ch2 = str.charAt(2)
            if ((ch0 == 'y' || ch0 == 'Y') &&
                (ch1 == 'e' || ch1 == 'E') &&
                (ch2 == 's' || ch2 == 'S') ) {
                return Boolean.TRUE
            }
            if ((ch0 == 'o' || ch0 == 'O') &&
                (ch1 == 'f' || ch1 == 'F') &&
                (ch2 == 'f' || ch2 == 'F') ) {
                return Boolean.FALSE
            }
        } else if (strlen == 4) {
            char ch0 = str.charAt(0)
            char ch1 = str.charAt(1)
            char ch2 = str.charAt(2)
            char ch3 = str.charAt(3)
            if ((ch0 == 't' || ch0 == 'T') &&
                (ch1 == 'r' || ch1 == 'R') &&
                (ch2 == 'u' || ch2 == 'U') &&
                (ch3 == 'e' || ch3 == 'E') ) {
                return Boolean.TRUE
            }
        } else if (strlen == 5) {
            char ch0 = str.charAt(0)
            char ch1 = str.charAt(1)
            char ch2 = str.charAt(2)
            char ch3 = str.charAt(3)
            char ch4 = str.charAt(4)
            if ((ch0 == 'f' || ch0 == 'F') &&
                (ch1 == 'a' || ch1 == 'A') &&
                (ch2 == 'l' || ch2 == 'L') &&
                (ch3 == 's' || ch3 == 'S') &&
                (ch4 == 'e' || ch4 == 'E') ) {
                return Boolean.FALSE
            }
        }
        return null
    }