JavaTutorial | Learn Java | Learning library

 by   codedata Java Version: Current License: No License

kandi X-RAY | JavaTutorial Summary

kandi X-RAY | JavaTutorial Summary

JavaTutorial is a Java library typically used in Tutorial, Learning applications. JavaTutorial has no vulnerabilities and it has low support. However JavaTutorial has 175 bugs and it build file is not available. You can download it from GitHub.

你可以在 [Google Play] 或 [Pubu] 上,取得本系列的電子書版本。.

            kandi-support Support

              JavaTutorial has a low active ecosystem.
              It has 30 star(s) with 26 fork(s). There are 5 watchers for this library.
              It had no major release in the last 6 months.
              There are 1 open issues and 0 have been closed. On average issues are closed in 1808 days. There are 1 open pull requests and 0 closed requests.
              It has a neutral sentiment in the developer community.
              The latest version of JavaTutorial is current.

            kandi-Quality Quality

              JavaTutorial has 175 bugs (0 blocker, 2 critical, 143 major, 30 minor) and 159 code smells.

            kandi-Security Security

              JavaTutorial has no vulnerabilities reported, and its dependent libraries have no vulnerabilities reported.
              JavaTutorial code analysis shows 0 unresolved vulnerabilities.
              There are 0 security hotspots that need review.

            kandi-License License

              JavaTutorial does not have a standard license declared.
              Check the repository for any license declaration and review the terms closely.
              Without a license, all rights are reserved, and you cannot use the library in your applications.

            kandi-Reuse Reuse

              JavaTutorial releases are not available. You will need to build from source code and install.
              JavaTutorial has no build file. You will be need to create the build yourself to build the component from source.
              Installation instructions are not available. Examples and code snippets are available.
              JavaTutorial saves you 2961 person hours of effort in developing the same functionality from scratch.
              It has 6390 lines of code, 537 functions and 233 files.
              It has low code complexity. Code complexity directly impacts maintainability of the code.

            Top functions reviewed by kandi - BETA

            kandi has reviewed JavaTutorial and discovered the below as its top functions. This is intended to give you an instant insight into JavaTutorial implemented functionality, and help decide if they suit your requirements.
            • Create the DvdD tables .
            • The main method .
            • Finds a director with the specified name .
            • Add a new dvd .
            • Return a list of Dvd objects .
            • Returns a String representation of this DvdObject .
            • Gets a user .
            • Add a new Dvd .
            • Set the DvdLibrary service .
            • Factory method to create an Account object .
            Get all kandi verified functions for this library.

            JavaTutorial Key Features

            No Key Features are available at this moment for JavaTutorial.

            JavaTutorial Examples and Code Snippets

            No Code Snippets are available at this moment for JavaTutorial.

            Community Discussions


            File Wrong Upload Jersey RestFull Service
            Asked 2021-Mar-02 at 20:55

            I really can't understand the reason for this error. I ran the sample application. It works correctly. Same code but cannot load correctly. I think the error is due to the version difference. Anyone have any suggestions for a solution?

            The web service I created



            Answered 2021-Mar-02 at 20:55

            The problem is that you are using Jersey 2.x, but your Multipart dependency is for Jersey 1.x. The two Jersey versions are incompatible. So the @FormDataParam annotation you using is just being ignored. That's why what you are getting in the InputStream is the entire multipart entity instead of just the file part.

            What you need to do is get rid of all your Jersey 1.x dependencies then add the Jersey 2.x jersey-media-multipart dependency.



            How to consume correctly from Kafka topic with Java Spark structured streaming
            Asked 2019-Jul-05 at 05:51

            I am new to kafka-spark streaming and trying to implement the examples from spark documentation with a Protocol buffer serializer/deserializer. So far I followed the official tutorials on


            and now I stuck on with the following problem. This question might be similar with this post How to deserialize records from Kafka using Structured Streaming in Java?

            I already implemented successful the serializer which writes the messages on the kafka topic. Now the task is to consume it with spark structured streaming with a custom deserializer.



            Answered 2019-Jul-05 at 02:49

            Did you miss this section of the documentation?

            Note that the following Kafka params cannot be set and the Kafka source or sink will throw an exception:

            • key.deserializer: Keys are always deserialized as byte arrays with ByteArrayDeserializer. Use DataFrame operations to explicitly deserialize the keys.
            • value.deserializer: Values are always deserialized as byte arrays with ByteArrayDeserializer. Use DataFrame operations to explicitly deserialize the values.

            You'll have to register a UDF that invokes your deserializers instead

            Similar to Read protobuf kafka message using spark structured streaming



            What is the use of Abstraction?
            Asked 2019-Feb-10 at 07:45

            I'm struggling to understand the overall use of Abstraction in Java.

            I have been working off an example in this link: I understand the implementation of it but I don't understand why its even necessary. Why is their a calculateSalary method made in the Employee class if they are just going to made again in the 2 subclasses?



            Answered 2019-Feb-10 at 07:45

            The overall use of abstraction is decoupling. To work with an Employee, one does not need to know the implementation, only the interface and its contracts. This is, for example, used for Collections.sort(List list): the programmers of Collections.sort(...) did not need to know the implementation of a specific list in order to sort it. This provides the benefit that the implementation support future code that conforms to the List interface. This question is related in that respect (#selfPromotion). Less coupling leads to less friction and overall less fragile code.

            That said, the example you provided is a poor one since it violates the Single Responsibility Principle: It is not the responsibility of an Employee instance to calculate the salary. For this, you should have a separate object that calculates the salary, based on an Employee-instance and some hours worked. Internally, this Uber-calculator could use a Chain of Responsibility, which hold one Calculator per Employee-Implementation, decoupling the Employee from how her/his salary is calculated. This provides the added benefit of extensability and flexibility: if the way a salary is calculated changes (e.g. maybe the company switches policy so that each FullTimeEmployee earns the same salary, or maybe the company wants to calculate the salary on a by-week instead of a by-month basis), other services using the FullTimeEmployee say unaffected).



            Type mismatch, expected: CodedInputStream, actual: FileInputStream
            Asked 2018-Dec-17 at 17:14

            val persons = Person()
            persons.mergeFrom(new FileInputStream("path_of_file"))

            Error : Type mismatch, expected: CodedInputStream, actual: FileInputStream



            Answered 2018-Dec-17 at 17:14

            You have to provide a CodedInputStream.




            Is this syntax formatting normal for Java?
            Asked 2018-Apr-17 at 18:19

            Came across this block of Java code from the Google Protocol Buffers Tutorial:



            Answered 2018-Apr-17 at 18:19

            That style of formatting is not completely normal in most code but when you are using a builder it is quite common since part of using a builder is the ability to chain calls to look like what you posted for readability.

            It replaces a long parameter list which also tend to have strange formatting.

            The dots indicate a call to the return value of the method on the previous line (Note that the line before each line starting with "." has no semi-colon). Every builder method returns "this" so that it can be chained in this way.

            If one wasn't interested in readability your example could be re-written like this:



            How to upload multiple files in dropbox using java
            Asked 2017-Nov-07 at 06:10

            I have created a java cucumber maven project. Now I want to push all report in dropbox once execution of test script is done.

            My main goal is to push report folder on Dropbox.

            I am using below maven dependency:



            Answered 2017-Nov-03 at 13:32

            The fact that it stuck on that line is normal. The program just expects the user's input from the console in order to proceed to the next line of code.



            JNetPcap Capture Packages No IPs returned
            Asked 2017-Aug-08 at 20:36

            I have this code from here But it does not return the src or destination ips. I can see the ip via



            Answered 2017-Aug-08 at 20:36

            Really simple they changed the code. Instead of

            ip.source(sIP); ip.destination(dIP);


            sIP = ip.source(); dIP = ip.destination();



            How to convert RDD of custom Java class objects to a DataFrame with toDF()?
            Asked 2017-Apr-29 at 19:54

            I am trying to convert a Spark RDD to a Spark SQL dataframe with toDF(). I have used this function successfully many times, but in this case I'm getting a compiler error:



            Answered 2017-Apr-29 at 19:51

            The reason for the compilation error is that there's no Encoder in scope to convert a RDD with com.example.protobuf.SensorData to a Dataset of com.example.protobuf.SensorData.

            Encoders (ExpressionEncoders to be exact) are used to convert InternalRow objects into JVM objects according to the schema (usually a case class or a Java bean).

            There's a hope you can create an Encoder for the custom Java class using org.apache.spark.sql.Encoders object's bean method.

            Creates an encoder for Java Bean of type T.

            Something like the following:



            What's meant by "identity-based Map" and "topology-preserving object graph transformations"?
            Asked 2017-Jan-11 at 12:21

            The JavaTutorials have this to say on IdentityHashMap:

            IdentityHashMap is an identity-based Map implementation based on a hash table. This class is useful for topology-preserving object graph transformations, such as serialization or deep-copying. To perform such transformations, you need to maintain an identity-based "node table" that keeps track of which objects have already been seen. Identity-based maps are also used to maintain object-to-meta-information mappings in dynamic debuggers and similar systems. Finally, identity-based maps are useful in thwarting "spoof attacks" that are a result of intentionally perverse equals methods because IdentityHashMap never invokes the equals method on its keys. An added benefit of this implementation is that it is fast.

            Could someone please explain in Simple English what is meant by both

            • "identity-based Map" and
            • "topology-preserving object graph transformations"?


            Answered 2017-Jan-11 at 10:43

            Read the Javadoc - as you always should if you need to understand a class.

            This class implements the Map interface with a hash table, using reference-equality in place of object-equality when comparing keys (and values). In other words, in an IdentityHashMap, two keys k1 and k2 are considered equal if and only if (k1==k2). (In normal Map implementations (like HashMap) two keys k1 and k2 are considered equal if and only if (k1==null ? k2==null : k1.equals(k2)).)


            A typical use of this class is topology-preserving object graph transformations, such as serialization or deep-copying. To perform such a transformation, a program must maintain a "node table" that keeps track of all the object references that have already been processed. The node table must not equate distinct objects even if they happen to be equal.


            Community Discussions, Code Snippets contain sources that include Stack Exchange Network


            No vulnerabilities reported

            Install JavaTutorial

            You can download it from GitHub.
            You can use JavaTutorial like any standard Java library. Please include the the jar files in your classpath. You can also use any IDE and you can run and debug the JavaTutorial component as you would do with any other Java program. Best practice is to use a build tool that supports dependency management such as Maven or Gradle. For Maven installation, please refer For Gradle installation, please refer .


            For any new features, suggestions and bugs create an issue on GitHub. If you have any questions check and ask questions on community page Stack Overflow .
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