Serialize interface

Serialize class is enabled by the class implementing the java. io. Serialize interface. Classes in place that this interface will not have any of their state serialized or de-serialized. All subtypes of a serialize class are serialize themselves. The serialization interface has no methods or fields and to identify identity serves only the semantics of being serialize.

To allow subtypes of non-serialize classes to be serialized, the subtype May assume Responsibility for saving and restoring the state of the super type’s public, protected, and (if accessible) package fields. The subtype May assume Responsibility this only if the class it extends has an accessible no-arg constructor to initialize the class's state. It is an error to declare a class Serialize if this is not the case. The errors will be detected at runtime.

During deserialization, the fields of non-serialize classes will be initialized using the public or protected no-arg constructor of the class. A no-arg constructor must be accessible to the subclass that is serialize. The fields of serialize subclasses will be restored from the stream.

When traversing a graph, an object May be Encountered that does not support the Serialize interface. In This case will be thrown the NotSerializeException will identify identity and the class of the non-serialize object.

That Classes require special handling serialization and deserialization during the process must special methods in Place with These exact signatures:

private void writeObject ( out)

throws IOException

private void readObject ( in)

throws IOException, ClassNotFoundException;

private void readObjectNoData ()

ObjectStreamException throws;

The writeObject method is responsible for writing the state of the object for class So THAT IT’S particularly the Corresponding readObject method can restore it. The default mechanism for saving the Object's fields can be invoked by calling out.defaultWriteObject. The method does not need to Concern with the state itself belonging con super classes or subclasses. State is saved by writing the single fields to the ObjectOutputStream using the writeObject method or by using the methods for primitive data types supported by DataOutput.

The readObject method is responsible for reading from the stream and restoring the classes’ fields. It May in.defaultReadObject call to invoke the default mechanism for restoring the object's non-static and non-transient fields. The defaultReadObject method use information in the stream to assign the fields of the object saved in the stream with the correspondingly named fields in the current object. This handles the case when the class has evolved to add new fields. The method does not need to concern with the state itself Belonging con sus superclasses or subclasses. State is saved by writing the single fields to the ObjectOutputStream using the writeObject method or by using the methods for primitive data types supported by DataOutput.

The readObjectNoData method is responsible for initializing the state of the object class for STIs particularly in the event That the serialization stream does not list the class as a superclass given the object of being de-serialized. This May Occur in cases Where the Receiving party use a different version of the de-serialized instance's class than the sending party, and the receiver's version extends classes that are not extended by the sender's version. This May Also Occur if the serialization stream has-been tampered; hence it, readObjectNoData is useful for initializing de-serialized objects DESPITE Properly to "hostile" or incomplete source stream.

That Serialize classes need to designate an alternative object to be used when writing an object to the stream should be special this in place with the exact method signature:

ANY-ACCESS-MODIFIER writeReplace Object () throws ObjectStreamException;

This method is writeReplace Invoked by serialization if the method exists and it would be accessible from a method defined within the class of the object being serialized. Just thus, the method CAN HAVE private, protected and package-private access. Subclass access to this method Follows java accessibility rules.

That Classes need to designate a replacement email when an instance is read from the stream should be special in the place with the exact method signature.

ANY-ACCESS-MODIFIER readResolve Object () throws ObjectStreamException;

This method readResolve follows the same invocation rules and accessibility rules as writeReplace.

The serialization runtime associates With Each serialize class a version number, called a serialVersionUID, Which is used During deserialization to verify the sender and receiver That of a serialized object That Have loaded classes for object That are Compatible with RESPECT to serialization. If the receiver has loaded a class for the object that has a different serialVersionUID Than That of the Corresponding sender's class, then a deserialization will result in an InvalidClassException. A serialize class can declare serialVersionUID its own explicitly by declaring a field named "serialVersionUID" that must be static, final, and of type long:

ANY-ACCESS static final long serialVersionUID MODIFIER = 42L;

If a serialize class does not explicitly declare a serialVersionUID, then a the serialization runtime will calculate a default serialVersionUID value for That class based on various Aspects of the class, as described in the Java (TM) Object Serialization Specification. However, it is strongly recommended That all serialize classes Explicitly declare serialVersionUID values, since the default serialVersionUID computation is highly sensitive to class details vary That May Depending on compiler implementations, and can just thus result in unexpected InvalidClassExceptions During deserialization. THEREFORE, to guarantee a consistent serialVersionUID value across different java compiler implementations, a serialize class must declare an explicit serialVersionUID value. It también está Strongly Advised That explicit serialVersionUID declarations use the private modifier Where Possible, since Such declarations Immediately apply only to the declaring class - serialVersionUID fields are not useful as inherited members. Array classes cannot declare an explicit serialVersionUID, So They Always Have the default computed value, but the requirement for matching serialVersionUID values is waived for array classes.

Transcendental Functions

Transcendental Functions


Rational and irrational functions, which have been treated in the preceding pages, these functions are called algebraic functions.

Functions that are not algebraic are called transcendental functions.

They are elementary transcendental functions

Exponential function:

f (x) = ax; a> 0, a ≠ 1.

Logarithmic function:

f (x) = loga (x); a> 0, a ≠ 1. It is inverse of the exponential.

Trigonometric functions:

Also called circular

f (x) = sin (x); f (x) = cos (x); f (x) = tan (x); f (x) = cosec (x); f (x) = sec (x) and f (x) = cotg (x)

There are other elementary functions such as hyperbolic and inverse trigonometric these and but do not intend in this teaching unit presenting all and rather analyze some cases, not overly complicated, which involved the former.

We must bear in mind the following points when analyzing for transcendental functions proposed in this teaching unit:

f (x) = x is defined for all x in R

f (x) = a-x = (1 / a) x, a> 1, 0 <1 / a <1

f (x) = loga (x) is defined for x> 0

We denote the logarithm log10 (x) by log (x) and the natural logarithm loge (x) by ln (x), where e = 2.718281 ... the called number 'e'

f (x) = sin (x) and f (x) = cos (x) are defined for all values of x. Its period is 2p

f (x) = tan (x) is undefined for x = p / 2 + kp. Its period is p.

In the case of composite functions such as: g (x) loga (g (x)), tg (g (x)), etc, must observe the composite domain of g (x) and the transcendent function.

Example: f (x) = log (x / (x-1)) is undefined for values of x / (x-1) where it it is not, x = 1, and for values x such that x / (x-1) is less than or equal to 0. Therefore Df = (- ¥, 0) U (1, + ¥)

As a review, the following program shows graphs of elementary transcendental functions: ex, ex and their inverses ln (x), log1 / e (x). Check that the inverse functions are symmetrical to each other with respect to the bisector of the first and third quadrants y = x. Analyze possible asymptotes and satellite branches posing.

The / the student will compare differences when editing exponential and logarithmic with different value based on replacing the entries f (x), g (x) h (x).

Note: The former function is represented in the program as exp (x) and ln (x) and log (x). Other exponential be given as x ^ xy any logarithmic loga (x) and log (x) / log (a).

The following program can proceed through the construction process of the function f (x) = ex / x which is analyzed in Example 1 (right margin)

Varying the pitch parameter 1 to 6 will be appearing on the scene the various elements needed to draw the graph:

Step 1: Domain

Step 2: Regions

Step 3: Parabolic Rama

Step 4: Asymptote

Step 5: Monotony and ends

Step 6: Drawing the curve


The parameter x can tour the independent variable in the domain of the function in increments of 0.125. But you can directly enter any value for x.

The deriv parameter is a switch two states 0 and 1. If deriv = 1 the value of f '(x) function that allows checking is displayed:

Ownership of monotony, f '(x)> 0 or f' (x) <0

Function singularity, F (x) = 0

Convexity when f '(x) increases

The concavity when f '(x) decreases

The editable input y = g (x) can be replaced by any functional expression and its graph is displayed facilitating any checks that are needed throughout the analysis. For example:

Replacing g (x) by (x-1) * exp (x) / x ^ 2 for f '(x)

Replacing g (x) for x ^ 2.2 * x + 2 is seen to f '' (x) to check that is always> 0


Example I analyzed 1

Analyze and represent the graph of f (x) = ex / x

a) Domain:

The ratio is not defined for x = 0, then Df = R- {0}

b) Cortes with the coordinate axes:

- Court OX: y = 0 is not possible as ex does not vanish.

- Court OY: x = 0 is not possible because it is not set to that value.

c) Regions:

As ex is positive for all x, it follows that f (x)> 0 for x> 0 and f (x) <0 for x <0.

d) Infinite Branches:

- Satellite Rama:

- Horizontal Asymptote: y = 0

- Vertical Asymptote: x = 0

e) Information about the first derivative:

Since ex> 0 and x2> 0, the sign of f '(x) is the sign of x-1.

f '(x) <0 if x <1: f (x) decreases for x <1

f '(x)> 0 if x> 1: f (x) increases for x> 1

f '(x) = 0 if x = 1: Minimum relative x = 1

f) Information about the second derivative:

Is easy to prove that x2-2x + 2> 0 for all x, so the sign of f '' (x) is the same as x3

f '' (x)> 0 if x> 0: f (x) convex

f '' (x) <0 if x <0: f (x) concave

No points of inflection

The following program can proceed through the construction process of the function f (x) = ln (x2 + 1) which is analyzed in Example 2 (right margin).

By varying the passage of 1-8 parameter will be appearing on the scene the various elements needed to draw the graph:

Step 1: Domain

Step 2: Regions

Step 3: Cortes with the axes

Step 4: Symmetry

Step 5: parabolic Branches

Step 6: Monotony and ends

Step 7: Turning points.

Step 8: Graph

Note: Consider the usefulness of the input parameters x and editable derive expression g (x) and use recommendations made in the previous year.