cglib | Byte Code Generation Library is high level API | Reflection library

 by   cglib Java Version: 3.3.0 License: Apache-2.0

kandi X-RAY | cglib Summary

kandi X-RAY | cglib Summary

cglib is a Java library typically used in Programming Style, Reflection applications. cglib has no bugs, it has no vulnerabilities, it has build file available, it has a Permissive License and it has high support. You can download it from GitHub, Maven.

cglib - Byte Code Generation Library is high level API to generate and transform Java byte code. It is used by AOP, testing, data access frameworks to generate dynamic proxy objects and intercept field access.

            kandi-support Support

              cglib has a highly active ecosystem.
              It has 4594 star(s) with 876 fork(s). There are 255 watchers for this library.
              It had no major release in the last 12 months.
              There are 68 open issues and 48 have been closed. On average issues are closed in 31 days. There are 22 open pull requests and 0 closed requests.
              It has a positive sentiment in the developer community.
              The latest version of cglib is 3.3.0

            kandi-Quality Quality

              cglib has 0 bugs and 0 code smells.

            kandi-Security Security

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

            kandi-License License

              cglib is licensed under the Apache-2.0 License. This license is Permissive.
              Permissive licenses have the least restrictions, and you can use them in most projects.

            kandi-Reuse Reuse

              cglib releases are available to install and integrate.
              Deployable package is available in Maven.
              Build file is available. You can build the component from source.

            Top functions reviewed by kandi - BETA

            kandi has reviewed cglib and discovered the below as its top functions. This is intended to give you an instant insight into cglib implemented functionality, and help decide if they suit your requirements.
            • Generate the class
            • Emits a list of methods
            • Generate bind callbacks
            • Process a switch assignment
            • Generates code to write a set of methods
            • Unboxes an object on the top of the stack
            • Allocates the arguments of the current method
            • Generate find proxy method
            • Runs the test program
            • Generate static code
            • Generates a set of methods
            • Generates getter method
            • Generate a class
            • Generates the get method
            • Generate key set
            • Declares an object field with given name and value
            • Wrap a class
            • Loads a class
            • Load a method
            • Generate the constructors
            • Generates setter method
            • Generates the code generator
            • Generate Swaps method
            • Performs a special switch on a method
            • Generates the put method
            • Intercept the method invocation
            Get all kandi verified functions for this library.

            cglib Key Features

            No Key Features are available at this moment for cglib.

            cglib Examples and Code Snippets

            copy iconCopy
            package de.scrum_master.spring.q70623926;
            import org.springframework.aop.framework.ProxyFactoryBean;
            import org.springframework.context.annotation.AnnotationConfigApplicat
            Spring Kafka bean configuration- why invoking bean method instead of autowire?
            Lines of Code : 21dot img2License : Strong Copyleft (CC BY-SA 4.0)
            copy iconCopy
             * Specify whether {@code @Bean} methods should get proxied in order to enforce
             * bean lifecycle behavior, e.g. to return shared singleton bean instances even
             * in case of direct {@code @Bean} method calls in user code. This feature
            Null dependencies in the proxy class
            Javadot img3Lines of Code : 36dot img3License : Strong Copyleft (CC BY-SA 4.0)
            copy iconCopy
            public class RequestTrackingService implements CompensateAware {
                public RequestTrackingRepository repository;
                public RequestTrackingService(RequestTrackingRepository repository) {
                    this.repository = repository;
            Not able to run SpringBoot 1.5.10.RELEASE on local tomcat(spring boot embedded) server
            Javadot img4Lines of Code : 30dot img4License : Strong Copyleft (CC BY-SA 4.0)
            copy iconCopy
            Now I am able to start the server without any of the above mentioned issues.
            SimpleEhCacheInterceptor is removed from version 1.3.0 to remove explicit caching instead caching is implemented internally in version 1.3.0 of spring batch admi
            Hibernate with Kotlin: @ManyToOne(fetch = FetchType.LAZY)
            Javadot img5Lines of Code : 16dot img5License : Strong Copyleft (CC BY-SA 4.0)
            copy iconCopy
             * Utility method that tries to properly initialize the Hibernate CGLIB
             * proxy.
             * @param 
             * @param maybeProxy -- the possible Hibernate generated proxy
             * @param baseClass -- the resulting class to be cast to.
             * @return the object

            Community Discussions


            java.lang.RuntimeException: not supported: class org.spockframework.gentyref.CaptureTypeImpl
            Asked 2022-Mar-30 at 13:59

            Spock is being used to execute an integration test in a Spring Boot project (2.1.18.RELEASE). When I run with 1.3-groovy-2.5, I get this error:



            Answered 2022-Mar-28 at 21:40

            Regarding java.util.ServiceConfigurationError: org.junit.platform.engine.TestEngine: org.spockframework.runtime.SpockEngine Unable to get public no-arg constructor

            Spring Boot 2.1.18.RELEASE is really old, it manages JUnit 5 to 5.3.2 while Spock 2.x requires >= 5.8. You can try setting 5.8.1 if you can't upgrade Spring Boot to a more recent version.

            As for the type reflection error, we can't say much since you didn't share any code. Only that probably has some weird generics or is calling something that does.



            Problem manipulating child entity of a OneToMany relation with Cascade ALL
            Asked 2022-Mar-14 at 17:38

            I have a performance problem using bi-directional relationship (OneToMany - ManyToOne).

            I have an entity Interaction that can have many ClassifiedGroup (see classes bellow for more details) but I have a specific use case where I need to delete few ClassifiedGroups and add few others.

            The problem is that when I use the itself (a simple JpaRepository) to save all modifications of related ClassifiedGroup, the code will have to fetch all groups from the database linked with an Interaction. It will also fetch many other attributes of the Interaction that can also be expensive. I do not want to manipulate the Interaction entity to delete/create new ClassifiedGroup but I also want to have the cascade type to ALL because I create the first groups when the Interaction is created and if I delete the interaction itself, all groups should be deleted.

            I tried to create a JpaRepository for the ClassifiedGroup entity and manipulate it directly but I'm getting errors trying to save it:




            Answered 2022-Mar-14 at 17:38

            Your mappings are incorrect - you'll need to look into JPA tutorials on how to map derived ids, but the error tells you what is wrong, pointing you at your ClassifiedGroup.interaction mapping(s). The PK class must use the Interaction's ID (a UUID), not the Interaction instance itself.



            What is causing Spring not to be able to load the configuration class when using AnnotationConfigApplicationContext?
            Asked 2022-Mar-03 at 16:25

            I've run across this issue recently and after searching the stackoverflow site, couldn't find a working solution. The error I'm getting is that Spring is having issue loading the configuration class. I'm using annotations and a Spring class to configure, instead of an XML file, to practice configuring Java apps with annotations instead of an XML file.

            I've double checked to make sure the needed annotations were there and that the Spring config file was marked with @Configuration and all of the beans inside the config file marked with @Bean. Also, the particular beans were marked with @Component.

            After creating a test class, it seems Spring is still having trouble finding the config file. I doubled checked the pom file to see if I was missing any dependencies but as far as I know, it seems the needed dependencies are there. I'm not sure what else I'm missing or why Spring is having trouble finding the config file. Any help would be greatly appreciated.

            Here is my pom.xml file:



            Answered 2022-Feb-28 at 19:30

            Since Java 9, Java introduced Modules and some frameworks such as Spring, rely on several Reflection behaviour and because of the modularization, some classes had their attribute not accessible through Reflection. The solution would be change the accessibility of these attributes, but it would take forever to do that.

            The real solution is to add this VM option when you run your application: --add-opens java.base/java.lang=ALL-UNNAMED

            Please refer to this great answer on another post with a similar problem: Answer to similar question

            I changed your application to use Spring Boot, have you consider using it? For Spring applications, it is a very handy solution since it abstract many configurations. Here is a link with a detailed example: Spring Boot Example



            Is it possible to instrument a program that also uses dynamic bytecode generation?
            Asked 2022-Feb-26 at 14:39

            I am writing a Java instrumentation program that uses the built-in Instrumentation API with Javassist (v3.26.0-GA) to intercept all the method calls in the target program. Also, I have implemented a REST API service inside this program using Java Spark to send requests for starting/stopping instrumentation by adding/removing transformers, and also for fetching intercepted methods during the instrumentation time.

            Now, while I was trying to run WebGoat (an open source Spring Boot application) with my Java agent attached from premain, I was not able to intercept all the methods successfully and in the log, there was a NotFoundException being thrown by Javassist.

            This error happened for several classes in WebGoat all had a similar common fact that they had something to do with SpringCGLIB. A few of the errors are shown below.



            Answered 2022-Feb-26 at 14:39

            From previous comments:

            The unfound classes are dynamic proxies which are heavily used by the Spring Framework in order to implement AOP. Spring can use both JDK dynamic interface proxies and CGLIB proxies, the latter of which is what we are seeing here. Maybe you should simply ignore those types of classes. They are in fact created dynamically, hence the name. But they are rather a result of dynamic (sub-)class generation than of bytecode transformation.

            Yes, I have considered just ignoring those dynamically generated classes, but the whole point of my application was to capture every single method invocation as a user interacts with the web application (such as clicking on a button, etc). In this case, would it be okay to ignore these types of dynamically generated classes? I want to make sure I do not miss any method calls.

            As those classes are just dynamic proxies, they will either forward the calls to the original methods or call some AOP or interceptor logic first/instead. Either way, you would not miss anything essential, those proxies are more like switchboards or routers, the actual show happens somewhere else. I recommend you to simply try in a little playgrounds project with an aspect or two.

            You also asked how to detect and ignore dynamic proxies by their names:

            • CGLIB proxies: Spring's CGLIB proxies contain substrings like $$FastClassBySpringCGLIB$$ or $$EnhancerBySpringCGLIB$$, followed by 8 characters representing 4 hexadecimal bytes. You could either match with a regular expression of just keep it simple and match the substring BySpringCGLIB$$. If non-Spring CGLIB proxies are also in use somewhere in your application, you would have to watch for other naming patterns. But probably you would get similar errors as before when not filtering them, so you would notice automatically.

            • JDK proxies: If your Spring application also happens to use JDK proxies, you can identify them easily using JRE API call Proxy.isProxyClass(Class). Thanks to Johannes Kuhn for his comment.

            • JDK proxies (old answer): You can filter class names beginning with $Proxy, usually something like com.sun.proxy.$Proxy2 (the trailing number being different). According to the JDK documentation: "The unqualified name of a proxy class is unspecified. The space of class names that begin with the string "$Proxy" is, however, to be reserved for proxy classes." At least for Oracle and probably OpenJDK, you can match for that naming pattern. If that holds true for all JVMs, is up to you to test, if chances are that in your environments others are being used. I quickly tried with Semeru OpenJ9, and the proxy naming pattern is identical, even the package name com.sun.proxy. Pleasae note that in more recent JDK versions, JDK proxies will have fully qualified names like jdk.proxy2.$Proxy25, so in e.g. Java 16 or 17 you should not rely on package name com.sun.proxy. Either add more cases or limit matching to the leading $Proxy in the simple class name.

            Update 2022-02-26: Because there was activity on this question, I decided to add some more information about Spring-specific tools which can determine whether an object (or a class) is an AOP proxy (class) and, more specifically, if it is a CGLIB or JDK proxy:

            Take a look at tool class AopUtils and its handy methods

            • isAopProxy(Object),
            • isCglibProxy(Object),
            • isJdkDynamicProxy(Object).

            No more String matching, simply ask Spring.

            BTW, there is also a method net.sf.cglib.proxy.Proxy.isProxyClass(Class) directly in CGLIB, which is supposed to do the same, but within Spring it does not work, probably because Spring uses CGLIB in a non-canonical way. Because Spring embeds a package-relocated CGLIB in its core, the corresponding method org.springframework.cglib.proxy.Proxy.isProxyClass(Class) yields the same faulty result. So if you are working within Spring, please do not use those methods, better use AopUtils.

            Here is some example code for your convenience, showing how to determine Spring AOP proxy types (JDK vs. CGLIB proxies) using AopUtils. See also my answer here for how to configure Spring in order to use both proxy types.

            BTW, instead of Javassist you could also use AspectJ for your purpose. It sounds like a pretty typical use case.



            SEVERE: Exception sending context initialized event to listener instance of class [org.springframework.web.context.ContextLoaderListener]
            Asked 2022-Feb-15 at 11:51

            so I'm in a new internship position and I was told to modernize a JEE applciation. I've migrated the code in my machine in both .rar , .tar.gz and raw source code , and I sotill get the same problem. so here is the full stack trace of the problem :



            Answered 2022-Feb-15 at 11:51

            Spring 3.2.0.RELEASE uses asm 4.0, which does not support Java 8 or higher.

            Since Java 7 is not supported any more, you should upgrade Spring to the latest patch release:



            How to fetch calendar events for a user using Microsoft Graph API with java
            Asked 2022-Jan-24 at 12:24

            I wish to connect a personal Microsoft account( to an App and then fetch the calendar events for that account using the App.

            I have registered the app in Aure portal and I am able to fetch the events using Postman. This is what my postman configuration looks like:



            Answered 2022-Jan-24 at 12:24

            My access token was missing a scope called: "Calendars.ReadWrite". This is how that scope was supposed to be added.



            How to resolve ClassCastException in MultiResourceItemReader Spring Batch
            Asked 2022-Jan-19 at 03:33

            I'm reading multiple files from the S3 bucket using MultiResourceItemReader, I'm getting ClassCastException before executing the myReader() method, Something wrong with MultiResourceItemReader not sure what's going wrong here.

            Please find my code below:



            Answered 2022-Jan-17 at 18:04

            The reason you see the NullPointerException is due to the default comparator used by the MultiResourceItemReader to sort the resources after loading them.

            The default compare behavior calls the getFilename() method of the InputStreamResource.

            Refer -

            But the InputStreamResource just inherits the getFileName() method from its parent AbstractResource, which just returns null.

            The solution is to provide a custom comparator for the MultiResourceItemReader. Here is a simple example, assuming you do not want to sort the resources in a specific way before processing:



            spring-aop On apple silicon (M1) : Illegal method name
            Asked 2022-Jan-12 at 00:35

            My working project uses kotlin + spring-boot.

            I found this issue when I try to run a test case having space like should success WHEN setting key is api updatable on the MacBook apple-m1 machine.




            Answered 2022-Jan-12 at 00:35

            You might be hitting Spring issue #21674 which was fixed in Spring 5.1. You might want to upgrade, if that is an option. It seems there is a fix which ignores those kinds of methods. If that is OK for you or not, I do not know.

            Some background information: Your target method is transactional, so Spring tries to create a CGLIB proxy for it. I quickly verified in a simple Spock (Groovy) test that CGLIB seems to be unable to handle methods containing spaces correctly -probably because it is simply unaware of languages like Groovy and Kotlin which allow such things. Here is a proof of concept. I used Groovy and Spock, because I am lazy and did not want to set up a Kotlin project. But I am expecting the result to be identical.

            Java class under test:



            Play framework in Java - errors in "hello world" example
            Asked 2022-Jan-11 at 12:09

            I'm trying to start working with play framework. I tried using the "hello world" example for Java, but after running the "sbt run" command I get errors. I get a lot of lines in the CMD, with the last few lines being:



            Answered 2022-Jan-11 at 12:09

            Play 2.8 supports Java 8-11, I set my environmental variable "JAVA_HOME" to the Java 8 JDK and the command sbt run worked.



            nested exception is org.hibernate.exception.SQLGrammarException:could not execute query] with root cause java.sql.SQLException: Column 'id' not found
            Asked 2021-Dec-26 at 12:54

            I'm doing a house rental application with Spring, React and MySQL. I have a class which is like a transaction. What I'm trying to do is to get all entries for the class sweetholiday_user_house, but I only want the fields start_rent_date and end_rent_date. The table is called sweet_holiday_user_house. For that I have created a SQL query in my repository:



            Answered 2021-Dec-25 at 22:09

            You are selecting a subset (start_rent_date and end_rent_date) of the columns of the table sweetholiday_user_house. However the results are being mapped to the managed entity SweetholidayUserHouse. So the mapping fails when it looks for the id column in the resultset, which is missing.

            You can avoid this exception by either of these two approaches. There are several more. Here is a good discussion of this - Spring JPA selecting specific columns

            Option 1: Keep the existing query and change the return type of the findAllReserved() method to Object[]. Here for each Object[], Object[0] is start_rent_date and Object[1] is end_rent_date.


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


            No vulnerabilities reported

            Install cglib

            You can download it from GitHub, Maven.
            You can use cglib 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 cglib 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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