Tag Archives: eclipse

[Solved] Error occurred during initialization of VM javalangNoClassDefFoundError javalangObject

When you run java/javac/java -version under the doc command, an error was reported:

Error occurred during initialization of VM java/lang/NoClassDefFoundError: java/lang/Object


Or eclipse cannot be opened for this reason

I summarized the following three reasons:

1: java environment variables are misconfigured, check the right and wrong environment variables, especially check the classpath

General (in the case of java configuration only), the value of the environment variable

JAVA_HOME ========= “your jdk installation directory” such as “C:Program FilesJavajdk1.8.0_121”

Path ========= “%JAVA_HOME%in;%JAVA_HOME%jrein”

CLASS_PATH ========= “%JAVA_HOME%libdt.jar;%JAVA_HOME%lib ools.jar”

2: If there is no problem with the environment variable configuration, then go to the jdk installation directory (such as C:Program FilesJavajdk1.8.0_121) and look for tools.jar under lib and rt.jar under jrelib to see if they exist, it is possible that rt.pack and tools.pack exist.

At this point, just unpack the corresponding files into rt.jar and tools.jar, and you can use the unpack200 tool inside the bin

#cd /usr/java/j2sdk1.4.2/lib
#unpack tools.pack tools.jar
#cd …/jre/lib
#…/…/unpack rt.pack rt.jar

3: There is no tools.jar under lib or rt.jar under jrelib, or there are missing files under lib or jrelib (40 files), so just copy them from elsewhere.

If you run java command after copying tools.jar or rt.jar, there may be missing files under jrelib, look carefully or just copy a whole jrelib, it can be solved.

[Solved] Tomcat Startup Error: Error deploying web application directory

The project has not been started for a long time. The following errors have been reported during the startup today:

The following methods have not been solved:

1. Clean the project and re-adddeployments to tomcat

2. Check the jar package in the build path and reconfigure the jdk

3. Checked the server.xml file under tomcat’s conf, and did not find the project path that reported the error

4. Check the path under the catalina folder under the conf of tomcat, and create a new folder according to the error, it is useless


Copy the servlet-api.jar in the Lib of Tomcat to the Lib of the project, and redeploy the project to solve the problem

[Solved] org.apache.maven.archiver.MavenArchiver.getManifest(org.apache.maven.project.MavenProject…

Error message:

org.apache.maven.archiver.MavenArchiver.getManifest(org.apache.maven.project.MavenProject, org.apache.maven.archiver.MavenArchiveConfiguration)



Add and change the following plugin configuration in pom:


[Solved] Project Error: Could not found sun.misc.BASE64Encoder

1. Questions

The project reported an error: could not found sun.misc.BASE64Encoder

2. Reason

Classes such as sun.misc.BASE64Encoder are not part of the JDK standard library, but the class is included in the JDK and can be used directly.

3. Solution

Replace sun.misc.BASE64Encoder with java.util.Base64


//import sun.misc.BASE64Encoder;
import java.util.Base64;//how to solve could not found sun.misc.BASE64Encoder error
// return new BASE64Encoder().encodeBuffer(bytes).trim().replaceAll("\r|\n", "");
return Base64.getEncoder().encodeToString(bytes);

[Solved] Ubuntu Eclipse C/C++ Error: launch failed.binary not found


Running on windows, there is either a problem with the installation of mingw64, or the header file cannot be found. Anyway, it is to verify whether the simulator can be used. What is the trouble? Just switch to Linux. The following are the results of running on Ubuntu.


To run the square studio export project, follow the readme of the exported project,

    1. install gcc
sudo apt-get install gcc g++ gdb build-essential
    2. install sdl
sudo apt-get install libsdl2-dev

3. Install eclipse c/c++
4. Select the parent folder of the exported project as “Workspace”
5. Select File->Import->General->Exisiting project into Workspace click “Next” and browse the project
6. Build the project with Project->Build
7. Run the project with Run->Run.
Then report an error: could not found lpng



    1Install lpng
sudo apt-get install libpng-dev

2. install CDT

help-> Check for updates

check CDT and install 

3. Modify the compiler

4. Just follow steps 6 and 7 above. The effect drawing is as follows

Eclipse start project error: Errors occurred during the build. Errors running builder ‘Integrated External Tool Builder’ on…

When eclipse starts the project, it suddenly reports: Errors occurred during the build. Errors running builder ‘Integrated External Tool Builder’ on project ‘acc-bid’. The builder launch configuration could not be found. The builder launch configuration could not be found.

The project kept building when it started, so I unchecked the validation box, which resulted in the above error

And when you look at buliders again, you bring a red cross

If you remove the fork, you won’t report an error

[Solved] Eclipse Error: A JNI error has occurred, please check your installation and try again


① Check whether the package name contains “Java” and modify it. Java should be avoided when creating the package.

② Run the Java version and javac version commands in CMD to check their own JDK and JRE versions. If they are different, reconfigure the environment variables to make them consistent

The above two steps can solve most of the problems. If they are still not solved, it is recommended to reinstall the JDK and reconfigure the environment variables.

[Solved] Eclipse Update Error: An error occurred while uninstalling session context was…

When updating Eclipse, the following error was reported:

An error occurred while uninstalling session context was:
(profile=D__…_…_eclipse_jee-2021-09_eclipse, phase=org.eclipse.equinox.internal.p2.engine.phases.Uninstall, operand=[R]org.eclipse.platform.ide.executable.win32.win32.x86_64 4.21.0.I20210906-0500 --> null, action=org.eclipse.equinox.internal.p2.touchpoint.natives.actions.CleanupzipAction).
Backup of file D:…eclipse.exe failed.
Can not remove : D:…eclipse.exe



    1.Run eclipse and Rename eclipse.exe to eclipse.exe.back
    2.Run updates
    3.Updates executed successfully

简而言之就是在启动eclipse后,再把eclipse exe重命名为eclipse.exe.back然后更新。

Eclipse: How to Close XML validation (xml file Error)

Eclipse turns off English spell checking and XML validation

To solve the problem, the servlet can run, but the XML file is red

Mode 1:

Windows–> Preferences–> XML –> XML Files –> Validate

Find validate and uncheck build

Mode 2:

Windows–> Preferences–> XML(Wild Web Developer)-> Validate& Resolution

Cancel enable validate

Or change both enable namespaces validate and enable schema based} validate to never

Then click apply and it will be OK

The first one, I don’t know whether it’s my eclipse version or something. I didn’t find that one. The second one can solve this problem. I hope it can help you!!

JSON parse error: invalid UTF-8 solution series [How to Solve]

Today, the following error message will be prompted when you copy the project from the old workspace to the directory of the new workspace:

Request","exception":"org.springframework.http.converter.HttpMessageNotReadableException","message":"JSON parse error: Invalid UTF-8 middle byte 0x3f

The reasons for the above errors are: the JVM parameter does not configure the encoding format and the eclipse workspace does not specify the encoding format.

Solution: specify the JVM encoding format

Open windows -> Preferences-> java-> Installed jres select the local JRE version and click Edit

Add specified encoding format:


Specify the Workspace encoding format.
window-Preferences-General-workspace-other: UTF-8

[Modified] ANTLR4 line 1:14 token recognition error at ‘(‘

Explore the errors reported by antlr4 by yourself:
line 1:14 token recognition error at '('
means that: (the column number needs to be + 1) the symbol recognition error ‘(‘) in 1 row and 14 columns; it means that the symbol ‘(‘) not recognized by G4 rules does not affect the operation
line 1:0 token recognition error at: '7'
in 1 row and 1 column: ‘7’ symbols have no matching rules