AOP | PECL extension that enables you to use Aspect Oriented | Aspect Oriented library
kandi X-RAY | AOP Summary
kandi X-RAY | AOP Summary
AOP is a PECL extension that enables you to use Aspect Oriented Programming in PHP, without the need to compile or proceed to any other intermediate step before publishing your code. The AOP extension is designed to be the easiest way you can think of for integrating AOP to PHP. AOP aims to allow separation of cross-cutting concerns (cache, log, security, transactions, ...).
Support
Quality
Security
License
Reuse
Top functions reviewed by kandi - BETA
Currently covering the most popular Java, JavaScript and Python libraries. See a Sample of AOP
AOP Key Features
AOP Examples and Code Snippets
Community Discussions
Trending Discussions on AOP
QUESTION
i am working in jave
, spring
, mysql
, hibernate
environment
I have the following hql
it gives me the correct out put
ANSWER
Answered 2021-Jun-15 at 07:06Instead of
QUESTION
I have two entity classes as follows. The Parachute
is the parent object and it has multiple Component
objects. I need to have bidirectional @OneToMany implemented here.
Parent Parachute.java
class.
ANSWER
Answered 2021-Jun-15 at 06:17You are violating the JPA spec by accessing the persistence context in a lifecycle listener.
See the JPA Specification 4.2 Section 3.5.2
In general, the lifecycle method of a portable application should not invoke EntityManager or query operations, access other entity instances, or modify relationships within the same persistence context. A lifecycle callback method may modify the non-relationship state of the entity on which it is invoked.
"a portable application should not" is the specification way of saying: Don't do that, anything might happen. Maybe the world ends.
The fix is not to do that. Maybe be preloading the currently logged in user and reference it so you may access it in your entity listener and do not set a reference to the user, but simple store its id or similar.
QUESTION
dispatcher-servlet.xml
...ANSWER
Answered 2021-Jun-14 at 02:53This issue is solved after correcting up my code
QUESTION
I'm getting this error because one of the fields in my domain class is a LocalDate. Stack trace below. Jackson is complaining about Java 8 date/time not being supported by default, but Spring Boot 2.5
comes with com.fasterxml.jackson.datatype:jackson-datatype-jsr310
. How do I get Spring Batch to support my LocalDate
field in my domain class?
If I change the field to be a java.util.Date
it works perfectly.
Thanks!
...ANSWER
Answered 2021-Jun-10 at 03:14You can add serializer and deserializer for it.
QUESTION
I am trying to upgrade from Spring Boot 2.2.x to 2.3 I have encountered an issue with the upgrade of spring-data-jdbc. In 1.1.x one could write the following query and it would work as expected
...ANSWER
Answered 2021-Jun-10 at 20:29It will be fixed with the upcoming Spring-data-jdbc 2.3.x. Relevant issue 974 has been closed.
QUESTION
I am trying to run a project in Java and came across the following issues:
...ANSWER
Answered 2021-Jun-07 at 14:33There's a suspicious library com.fasterxml.jackson.databind.jar
in your WEB-INF/lib. I'd kick it out, because it's probably shadowing jackson-databind-2.9.4.jar
. The addMixin
method exists since 2.5, so that com.fasterxml.jackson.databind.jar
must be 2.4 or older.
BTW, according to https://mvnrepository.com/artifact/org.springframework/spring-web/5.1.0.RELEASE, you should use jackson 2.9.7, but maybe 2.9.4 works, too.
QUESTION
I'm doing my student project and building a testing tool for regression testing.
Main idea: capture all constructors/methods/functions invocations using AOP during runtime and record all data into a database. Later retrieve the data, run constructors/methods/functions in the same order, and compare return values.
ProblemI'm trying to serialize objects (and arrays of objects) into a byte array, record it into PostgreSQL as a blob, and later (in another runtime) retrieve that blob and deserialize it back to object. But when I deserialize data in another runtime it changes and, for example, instead of boolean
, I retrieve int
. If I do exactly the same operations in the same runtime (serialize - insert into the database - SELECT from the database - deserialize) everything seems to work correctly.
Here is how I record data:
...ANSWER
Answered 2021-Jun-07 at 12:32An explosion of errors and misguided ideas inherent in this question:
Your read and write code is broken.available()
doesn't work. Well, it does what the javadoc says it does, and if you read the javadoc, and read it very carefully, you should come to the correct conclusion that what that is, is utterly useless. If you ever call available()
, you've messed up. You're doing so here. More generally your read and write code doesn't work. For example, .read(byteArr)
also doesn't do what you think it does. See below.
You can't 'save the state' of arbitrary objects, and if you want to push the idea, then if you can, then certainly not in the way you're doing it, and in general this is advanced java that involves hacking the JDK itself to get at it: Think of an InputStream that represents data flowing over a network connection. What do you imagine the 'serialization' of this InputStream object should look like? If you consider serialization as 'just represent the underlying data in memory', then what you'd get is a number that represents the OS 'pipe handle', and possibly some IP, port, and sequence numbers. This is a tiny amount of data, and all this data is completely useless - it doesn't say anything meaningful about that connection and this data cannot be used to reconstitute it, at all. Even within the 'scope' of a single session (i.e. where you serialize, and then deserialize almost immediately afterwards), as networks are a stream and once you grab a byte (or send a byte), it's gone. The only useful, especially for the notion of 'lets replay everything that happened as a test', serialization strategy involves actually 'recording' all the bytes that were picked up, as it happens, on the fly. This is not a thing that you can do as a 'moment in time' concept, it's continuous. You need a system that is recording all the things (it needs to be recording every inputstream, every outputstream, every time System.currentTimeMillis()
in invoked, every time a random number is generated, etc), and then needs to use the results of recording it all when your API is asked to 'save' an arbitrary state.
Serialization instead is a thing that objects need to opt into, and where they may have to write custom code to properly deal with it. Not all objects can even be serialized (an InputStream representing a network pipe, as above, is one example of an object that cannot be serialized), and for some, serializing them requires some fancy footwork, and the only hope you have is that the authors of the code that powers this object put in that effort. If they didn't, there is nothing you can do.
The serialization framework of java awkwardly captures both of these notions. It does mean that your code, even if you fix the bugs in it, will fail on most objects that can exist in a JVM. Your testing tool can only be used to test the most simplistic code.
If you're okay with that, read on. But if not, you need to completely rethink what you're going to do with this.
ObjectOutputStream sucksThis is not just my opinion, the openjdk team itself is broadly in agreement (they probably wouldn't quite put it like that, of course). The data emitted by OOS is a weird, inefficient, and underspecced binary blob. You can't analyse this data in any feasible way other than spending a few years reverse engineering the protocol, or just deserializing it (which requires having all the classes, and a JVM - this can be an acceptable burden, depends on your use case).
Contrast to e.g. Jackson which serializes data into JSON, which you can parse with your eyeballs, or in any language, and even without the relevant class files. You can construct 'serialized JSON' yourself without the benefit of first having an object (for testing purposes this sounds like a good idea, no? You need to test this testing framework too!).
How do I fix this code?If you understand all the caveats above and somehow still conclude that this project, as written and continuing to use the ObjectOutputStream API is still what you want to do (I really, really doubt that's the right call):
Use the newer APIs. available()
does not return the size of that blob. read(someByteArray)
is not guaranteed to fill the entire byte array. Just read the javadoc, it spells it out.
There is no way to determine the size of an inputstream by asking that inputstream. You may be able to ask the DB itself (usually, LENGTH(theBlobColumn)
works great in a SELECT query.
If you somehow (e.g. using LENGTH(tbc)) know the full size, you can use InputStream's readFully
method, which will actually read all bytes, vs. read
, which reads at least 1, but is not guaranteed to read all of it. The idea is: It'll read the smallest chunk that is available. Imagine a network pipe where bytes are dribbling into the network card's buffer, one byte a second. If so far 250 bytes have dribbled in and you call .read(some500SizeByteArr)
, then you get 250 bytes (250 of the 500 bytes are filled in, and 250
is returned). If you call .readFully(some500SizeByteArr)
, then the code will wait about 250 seconds, and then returns 500, and fills in all 500 bytes. That's the difference, and that explains why read
works the way it does. Said differently: If you do not check what read()
is returning, your code is definitely broken.
If you do not know how much data there is, your only option involves a while
loop, or to call a helper method that does that. You need to make a temporary byte array, then in a loop keep calling read until it returns -1. For every loop, take the bytes in that array from 0 to (whatever the read
call returned), and send these bytes someplace else. For example, a ByteArrayOutputStream
.
when I deserialize data in another runtime it changes and, for example, instead of boolean, I retrieve int
The java serialization system isn't magically changing your stuff on you. Well, put a pin that. Most likely the class file available in the first run (where you saved the blob in the db) was different vs what it looked like in your second run. Voila, problem.
More generally this is a problem in serialization. If you serialize, say, class Person {Date dob; String name;}
, and then in a later version of the software you realize that using a j.u.Date
to store a date of birth is a very silly idea, as Date is an unfortunately named class (it represents an instant in time and not a date at all), so you replace it with a LocalDate
instead, thus ending up with class Person{LocalDate dob; String name;}
, then how do you deal with the problem that you now want to deserialize a BLOB that was made back when the Person.class
file still had the broken Date dob;
field?
The answer is: You can't. Java's baked in serialization mechanism will flat out throw an exception here, it will not try to do this. This is the serialVersionUID
system: Classes have an ID and changing anything about them (such as that field) changes this ID; the ID is stored in the serialized data. If the IDs don't match, deserialization cannot be done. You can force the ID (make a field called serialVersionUID
- you can search the web for how to do that), but then you'd still get an error, java's deserializer will attempt to deserialize a Date object into a LocalDate dob;
field and will of course fail.
Classes can write their own code to solve this problem. This is non-trivial and is irrelevant to you, as you're building a framework and presumably can't pop in and write code for your testing framework's userbase's custom class files.
I told you to put a pin in 'the serialization mechanism isnt going to magically change types on you'. Put in sufficient effort with overriding serialVersionUID and such and you can end up there. But that'd be because you wrote code that confuses types, e.g. in your readObject
implementation (again, search the web for java's serialization mechanism, readObject/writeObject - or just start reading the javadoc of java.io.Serializable
, that's a good starting-off point).
You create objects for no purpose, you seem to have some trouble with the distinction between a variable/reference and an object. You aren't using try-with-resources. The way your SELECT calls are made suggests you have an SQL injection security issue. e.printStackTrace()
as line line in a catch block is always incorrect.
QUESTION
I am trying to save/persist multiple objects from a collection to a DB but i keep getting error. I have debugged and found out that this issue come when i try to save product. This exception comes on my ec2 instance server on my local workspace/machine.
ERORR:
...ANSWER
Answered 2021-Jun-06 at 20:52I have fixed the issue, the issue was with the hibernate itself, i am using 5.2.1 and this issue was fixed in 5.3
I updated my hibernate maven dependency to 5.3.0 and the issue
See here for the fix
QUESTION
In my mysql table has column that store 'JSONArray'
This is a part of model class in spring-boot project.
...ANSWER
Answered 2021-Jun-05 at 13:50Could you try below solution?
Need to declare answers
column as Lob
as shown in below example:
QUESTION
I am desperately trying to migrate a Spring MVC 4.3.4.RELEASE application with Hibernate 4.3.8.Final to the latest version of Spring Boot, i.e. Spring Boot 2.5
The idea is to turn it into a Restful API and to drop all views.
Note : I did not create a custom configuration on the new spring-boot project.
My architecture looks like :
- The controller
- The DTO
- The service
- The DAO
- The entity
Here is my pom.xml file :
...ANSWER
Answered 2021-Jun-04 at 13:17In ApplicationConf
you tell Hibernate to scan the com.package.repository
package but your Bus
entity class seems to be in the com.package.model
package.
Try changing:
Community Discussions, Code Snippets contain sources that include Stack Exchange Network
Vulnerabilities
No vulnerabilities reported
Install AOP
Support
Reuse Trending Solutions
Find, review, and download reusable Libraries, Code Snippets, Cloud APIs from over 650 million Knowledge Items
Find more librariesStay Updated
Subscribe to our newsletter for trending solutions and developer bootcamps
Share this Page