JSONArray dataArray=JSONArray.parseArray(JSON.toJSONString(datalist))
Solutions:
JSONArray dataArray=JSONArray.parseArray(JSON.toJSONString(datalist,SerializerFeature.WriteMapNullValue))
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A yellow warning appears on the pagecontroller page in PHP! ! ! !
* *
On the problem of error reporting in Pagecontroller in PHP
* *
looks just like me a lot of people started just dumb to find why the error, but this is not a mistake, page controller is running, just no display in the current page, so there will be prompted to alert, so you need to add url address behind you to display the page address (the name of the PHP file)
if
and error before the url is:
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did not report an error when it was opened for the first time, but when it was opened again the next day, I do not know how to report an error. Moreover, it was an error in the source code.
this error probably speak pathinfo is not open, online a lot of code is said to modify the PHP ini file configuration inside, but I was configured also not the last line error, finally it is helpless, can only reinstall warmserver, the import pagecontroller, but still no use, it’s helpless, had to once again to look for ways to solve the problem, and finally found that there is no creation page, really sick…
the first step is to locate the php.ini file,e… I didn’t know where to start, because there were so many directories that I couldn’t find them, and then I started searching the Internet for where the files were. So there are still a lot of detours in the beginning of a language, and these detours are also another kind of learning of the language.
error LNK2019: Unresolved external symbol-resolution record
Error LNK2019: External symbol that cannot be resolved
Vs2015 recently encountered a compile problem, error LNK2019: cannot resolve the external symbol of
from some search on the net, compare to see the, the project properties dependent libraries do not have what problem, win32 platform no problem, 32 bit ok
finally found their own header file, found in. H and. Repeated wrote the new CPP rely on header files, remove after returning to normal
ConfigurationProperties configuration class
@ ConfigurationProperties configuration class
- defines entity class (omit set, get method)
writes application. Yml configuration file
tests
test results 
Install Oracle VM VirtualBox Extension Pack failed to install the extension pack
The version of VirtualBox is not correct
In the terminal
dpkg-query -l
View the VirtualBox version number
Download the correct version of extPack from here
http://download.virtualbox.org/virtualbox

How to Fix Tomcat Error: Failed to destroy end point associated with ProtocolHandler[ajp-nio-8009]

Foreground summary: The maven repository that we installed is by default in the M2/Repository on disk C, but Windows users have their operating systems installed on disk C, so it is dangerous to put the Maven repository on disk C, so we need to modify the local repository path. Today the framework of the maven dependent libraries to replace the download address and the location of the store, because before use is a website, download or update the configuration file is particularly slow, is really can’t stand to replace more ali cloud with maven repositories, feel the speed suddenly increased n level, of course, the error is also my errors after running Tomcat after change.

Problem: Because I changed the location of the Maven repository’s Settings.xml, the configuration environment was inconsistent with the default environment variables, causing Tomcat to run incorrectly.
Solutions:1. Open MyEclipse and click Windows-& GT; preferences-> maven-> Add a Maven that has been installed in the D:\Java directory, as: D:\Java\ Maven-3.0.4, and check the attached item. And click the browse button below to open Maven’s global configuration file, such as D:\Java\ Maven-3.0.4 \conf\ fine.xml. (Skip this step if it is already installed)
2. Open MyEclipse and click Windows-& GT; preferences-> maven-> Under User Setting, change the User Setting option to D:\Java\m2\ Repository \ Settings. XML, and click Update Settings. And click the reIndex button below to update the index.
3. Click the Apply button in the configuration window to highlight the configuration window.
4. Finally, open CMD and execute MVN help: System. You will find that all the JARS Maven downloads from the remote library will be placed in the newly modified path D:\Java\m2\ Repository.
How to Fix Android Error:This Gradle plugin requires Studio 3.0 minimum
I’ve talked a little bit about this before, and it’s a little bit incomplete, so let me write it down again.Reason: The project USES version 3.0 and the computer installed version 2.2.2. The error report of the imported project Gradle
Solutions:
Solution a:
Build. Gradle

Instead of ‘com. Android. Tools. Build: gradle: 2.3.3’
Scheme 2:
Gradle. In the properties
Add android. Injected. Build. Model. Only the versioned = 3
If not, or continue to gradle. The properties file to add an android. Injected. TestOnly = false
Android :This Gradle Plugin requires Studio 3.0 minimum.
It’s that simple.
How to Fix char cannot be dereferenced Error
error: char cannot be dereferenced
Error code
if(row.charAt(m).equals('0')){
matrix[i][j]=0;
}
Where the row is a string.
2. Error reason
Ross: Yeah, I mean, derefrence. The value that points to
The type char is a primitive — not an object — so it cannot be dereferenced
derefer0 derefer0 is The process of authentication The value green to by a reference. Since a char is already a value (not a) reference), it can not be dereferenced.
use Character class:
if(Character.isLetter())
char
char
char is a primitive type.
Character is its wrapper class, reference type, and equals() method. == instead of directly comparing values.
git push fatal Error: HttpRequestException encountered.
Reason: Github disabled TLS V1.0 and V1.1 and had to update Windows git credence manager
https://github.com/Microsoft/Git-Credential-Manager-for-Windows/releases/tag/v1.18.2
You can download and install it


python3 Error in sitecustomize; set PYTHONVERBOSE for traceback: NameError: name ‘modules_list’ …
Error in sitecustomize; set PYTHONVERBOSE for traceback:
NameError: name ‘modules_list’ is not defined

Problem. PNG
Modify a file called sitecustomize.py to be located under C:\python3\Lib\site-packages and change the name to Sitecustomize_back. py

File location. PNG

File name modified. PNG

Run without error. PNG
com.android.ddmlib.AdbCommandRejectedException: device offline Error while Installing APK (How to Fix)
com.android.ddmlib.AdbCommandRejectedException:device offline
Error while Installing APK
The problem is that ADB is killed, just restart it
There are three ways:
1. Plattform-tools can be found in the SDK file, and adb can be found in this folder.
Double-click ADB to restart it
Second, you can also perform a two-step command operation in CMD:
1, the adb kill server
2, the adb start – server
Restart the computer
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copyright notice: this article is the original article of CSDN blogger “shenshizhong”, in accordance with CC 4.0 by-sa copyright agreement, please attach the source link and this statement.
Pytorch RuntimeError CuDNN error CUDNN_STATUS_SUCCESS (How to Fix)
When I used RNN in Pytorch and sent it to the GPU for computation, there was:
RuntimeError: CuDNN error: CUDNN_STATUS_SUCCESS
Before the error appeared, my environment was:
OS: Ubuntu 16.0.4
GPU: NVIDIA GForce RTX 2080 (view GPU and driver information can be used command: nvidia-smi)
CUDA: cuda9.0
cudnn: 7.x for cuda9.0
Look up the solution on the Internet, in fact, encountered this kind of problem is very simple, is
1. Update cuda and cudnn
change your cuda and cudnn to 9.2 or 10.0 or above the lowest version of cuda supported by your GPU;
2. Update pytorch and torchvision versions
remember, after updating cuda and cudnn, be sure to update pytorch to a version suitable for your cuda, such as torch0.4.1 for cuda9.2.
After the above 2 steps, you can basically solve this problem. The reference method is as follows:
https://discuss.pytorch.org/t/runtimeerror-cudnn-error-cudnn-status-success/28045).