JAVA environment variable configuration

This article introduces some error reports and solutions caused by the configuration of Java environment variables.

Note: the JDK version supported by finebi is JDK 1.8 and the minor version must be above jdk8u102.

1. log error: Unsupported major minor version 52.0

1) phenomenon 1: this error is reported in the startup log, the startup fails, and the platform 404 is accessed

Cause analysis

Finebi no longer supports jdk1.7 and below since September 2, 2020, and only supports JDK1.8.

Solution

The JDK version to be replaced is JDK 1.8 and the minor version must be above jdk8u102.

2) phenomenon 2: this error occurs during project operation, and the corresponding plug-in cannot be used

Cause analysis

The JDK version used by the plug-in compilation is higher than the JDK version of the running environment variable.

Solution

The compiled versions of the officially released plug-ins are not higher than JDK1.8, and the Java environment can be changed to JDK1.8.

2. start failure: fine assist start failed.

1) phenomenon 1

Problem description

Log error:Caused by: com.sun.tools.attach.AttachNotSupportedException: no providers installed.

Cause analysis

When installing JDK under windows, an independent jre will be installed at the same time. There is no attach.dll under the independent jre, which needs to be called for FineBI startup.

Solution

Configure JRE_HOME cannot point to jre installed independently, and %JAVA_HOME%\jre must be used.

2) phenomenon II

Problem description

Log error: Caused by: java.lang.UnsatisfiedLinkError: sun.tools.attach.LinuxVirtualMachine.isLinuxThreads()Z

Cause analysis

Linux tools are installed in the lower part of windows jar 。

Linux's tools.jar are deployed under Windows.

Solution

Get tools.jar from %JAVA_HOME%\lib, move to webroot/WEB-INF/lib or tomcat/lib.

3) phenomenon 3

Problem description

Log error: Caused by: com.sun.tools.attach.AgentLoadException: Failed to load agent library.

a. Reason 1:

Reason: there is a problem with the JDK. It may be the wrong number of digits, or the JDK may be incomplete and lack some functions.

Solution: if you do not confirm, first use uname to obtain the operating system version, and then install the corresponding version of JDK. Note that x86 refers to Intel's operating system architecture. X86_ 64 is 64 bit and i586 is 32 bit.

b. Reason 2:

Reason: The file FineAssist_xx.so pointed to has a problem and cannot be loaded.

Solution: get FineAssist_xx.so from the core package again. Reinstall the so file of the classified machine.

4) phenomenon 4

Problem description

Similar errors caused by non JDK, such as: 

Caused by: com.sun.tools.attach.AttachNotSupportedException: Unable to open socket file: target process not responding or HotSpot VM not loaded

This error appears to be similar to the error caused by the JDK problem, but it is not necessarily caused by the JDK.

Cause analysis

/tmp directory cannot write files. The possible causes of this phenomenon are:

• Ordinary users do not have permission.

• The disk space where /tmp is located is full.

Solution

• If you do not have permission, open the permission of the /tmp directory.

• If there is enough disk space, clean up the corresponding disk space.

3. problems in some JDK versions

1) jdk1.8.0_ Versions below 65 may cause startup flash back

Problem description

Log error: java.lang.IllegalArgumentException: object is not an instance of declaring class

Cause analysis

Bytebuddy version is incompatible.

Solution

Upgrade the JDK version. It is recommended to upgrade to a higher version of JDK1.8.

2) jdk1.8.0_ 171 may result in blank template preview

Problem description

All template previews are blank.

Cause analysis

oracle1.8.0_171_b11 causes the template preview to be blank.

Solution

The JDK version to be replaced is JDK 1.8 and the minor version must be above JDK8u102.

1. Windows system

Modify catalina.bat under tomcat/bin (take deployment package as an example), as shown in the following figure:

2. Linux system

Modify catalina.sh under tomcat/bin (take deployment package as an example), as shown in the following figure:

It is a special requirement to specify the JDK path under the deployment package for Linux. It must be after CATALINA_HOME is defined and before JAVA_HOME is called for the first time, so this location can only be added.

The non deployment package can point to the JDK under the absolute path. There is no restriction of CATALINA_HOME, so it can be added before JAVA_HOME is called for the first time.