Difference between revisions of "Java8"
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* Because Java 10 breaks more things | * Because Java 10 breaks more things | ||
* Because Java 11 breaks even more things | * Because Java 11 breaks even more things | ||
| − | * Because Java >=12 | + | * Because Java >=12 broke more of the stuff that has been working perfectly for years |
| − | And the cost/benefit relation of moving along Oracle's ideas seems not worthwile. | + | And the cost/benefit relation of moving along Oracle's ideas seems not worthwile. |
| + | == What can you do ?? == | ||
| + | # Stick to Java 8 | ||
| + | # Move to another programming language like Python, Javascript or any other [https://www.tiobe.com/tiobe-index/ competitor of Java] | ||
| + | === Stick to Java 8 === | ||
| + | <source lang='bash' highlight='1,2,11,13'> | ||
| + | sudo apt install openjdk-8-jdk | ||
| + | sudo update-alternatives --config java | ||
| + | There are 2 choices for the alternative java (providing /usr/bin/java). | ||
| + | |||
| + | Selection Path Priority Status | ||
| + | ------------------------------------------------------------ | ||
| + | * 0 /usr/lib/jvm/java-11-openjdk-armhf/bin/java 1111 auto mode | ||
| + | 1 /usr/lib/jvm/java-11-openjdk-armhf/bin/java 1111 manual mode | ||
| + | 2 /usr/lib/jvm/java-8-openjdk-armhf/jre/bin/java 1081 manual mode | ||
| + | |||
| + | Press <enter> to keep the current choice[*], or type selection number: 2 | ||
| + | update-alternatives: using /usr/lib/jvm/java-8-openjdk-armhf/jre/bin/java to provide /usr/bin/java (java) in manual mode | ||
| + | wf@raspberrypi:~/source/java/com.bitplan.dac $ java -version | ||
| + | openjdk version "1.8.0_312" | ||
| + | OpenJDK Runtime Environment (build 1.8.0_312-8u312-b07-1+rpi1-b07) | ||
| + | OpenJDK Client VM (build 25.312-b07, mixed mode) | ||
| + | </source> | ||
= Examples = | = Examples = | ||
| Line 58: | Line 80: | ||
=== Therapy === | === Therapy === | ||
Surprise - stay with Java 8 ... | Surprise - stay with Java 8 ... | ||
| + | == Incompatible Javadoc == | ||
| + | === Problem === | ||
| + | <pre> | ||
| + | [ERROR] Failed to execute goal org.apache.maven.plugins:maven-javadoc-plugin:3.0.1:jar (attach-javadocs) on project com.bitplan.rest.freemarker: MavenReportException: Error while generating Javadoc: | ||
| + | |||
| + | [ERROR] Exit code: 1 - javadoc: error - The code being documented uses modules but the packages defined in https://docs.oracle.com/javase/8/docs/api/ are in the unnamed module. | ||
| + | |||
| + | [ERROR] | ||
| + | |||
| + | [ERROR] Command line was: /usr/local/lib/jvm/openjdk11/bin/javadoc -Xdoclint:none @options @packages | ||
| + | </pre> | ||
| + | === Diagnosis === | ||
| + | <source lang='bash'> | ||
| + | java -Xmx32m -version | ||
| + | |||
| + | openjdk version "11.0.2" 2019-01-15 | ||
| + | </source> | ||
| + | Java 11 javadoc is incompatible to prior versions | ||
| + | === Therapy === | ||
| + | Surprise - stay with Java 8 ... | ||
| + | == mvn site fails == | ||
| + | === Problem === | ||
| + | <pre> | ||
| + | org.apache.bcel.classfile.ClassFormatException: Invalid byte tag in constant pool: 19 | ||
| + | at org.apache.bcel.classfile.Constant.readConstant (Constant.java:161) | ||
| + | </pre> | ||
| + | === Diagnosis === | ||
| + | * https://stackoverflow.com/questions/49383179/org-apache-bcel-classfile-classformatexception-invalid-byte-tag-in-constant-poo | ||
| + | * upgrading maven site plugin to https://mvnrepository.com/artifact/org.apache.maven.plugins/maven-site-plugin/3.9.0 does not help | ||
| + | |||
| + | === Therapy === | ||
Latest revision as of 10:53, 16 June 2022
Why Java 8 is not dead
- Because Java 9 breaks things
- Because Java 10 breaks more things
- Because Java 11 breaks even more things
- Because Java >=12 broke more of the stuff that has been working perfectly for years
And the cost/benefit relation of moving along Oracle's ideas seems not worthwile.
What can you do ??
- Stick to Java 8
- Move to another programming language like Python, Javascript or any other competitor of Java
Stick to Java 8
sudo apt install openjdk-8-jdk
sudo update-alternatives --config java
There are 2 choices for the alternative java (providing /usr/bin/java).
Selection Path Priority Status
------------------------------------------------------------
* 0 /usr/lib/jvm/java-11-openjdk-armhf/bin/java 1111 auto mode
1 /usr/lib/jvm/java-11-openjdk-armhf/bin/java 1111 manual mode
2 /usr/lib/jvm/java-8-openjdk-armhf/jre/bin/java 1081 manual mode
Press <enter> to keep the current choice[*], or type selection number: 2
update-alternatives: using /usr/lib/jvm/java-8-openjdk-armhf/jre/bin/java to provide /usr/bin/java (java) in manual mode
wf@raspberrypi:~/source/java/com.bitplan.dac $ java -version
openjdk version "1.8.0_312"
OpenJDK Runtime Environment (build 1.8.0_312-8u312-b07-1+rpi1-b07)
OpenJDK Client VM (build 25.312-b07, mixed mode)
Examples
Mediawiki-Japi
Problem
Mediawiki-Japi/src/main/java/com/bitplan/mediawiki/japi/api/Page.java:[34,33] package javax.xml.bind.annotation does not exist
Diagnosis
Oracle decided to remove APIs
Solution
Do not use Oracle's incompatible Java versions - stay with Version 8
diff --git a/.travis.yml b/.travis.yml
# this is a java project using maven
language: java
+# make sure things keep working see http://wiki.bitplan.com/index.php/Java8
+jdk: openjdk8
Crashing Eclipse
Problem
Trying to start Eclipse oxygen leads to multiple ClassNotFoundExceptions
Diagnosis
- https://bugs.eclipse.org/bugs/show_bug.cgi?id=533390
- https://stackoverflow.com/questions/48349760/how-do-i-change-my-eclipse-ides-launch-jvm
Therapy
Surprise - stay with Java 8 ... Search it:
/usr/libexec/java_home -v 1.8
/Library/Java/JavaVirtualMachines/jdk1.8.0_152.jdk/Contents/Home
and add it to your eclipse.ini (make sure using two lines as below ...
-vm /Library/Java/JavaVirtualMachines/jdk1.8.0_152.jdk/Contents/Home/bin/java
Hazelcast not starting properly
Problem
java: WARNING: Hazelcast is starting in a Java modular environment (Java 9 and newer) but without proper access to required Java packages. Use additional Java arguments to provide Hazelcast access to Java internal API. The internal API access is used to get the best performance results. Arguments to be used: java: --add-modules java.se --add-exports java.base/jdk.internal.ref=ALL-UNNAMED --add-opens java.base/java.lang=ALL-UNNAMED --add-opens java.base/java.nio=ALL-UNNAMED --add-opens java.base/sun.nio.ch=ALL-UNNAMED --add-opens java.management/sun.management=ALL-UNNAMED --add-opens jdk.management/com.sun.management.internal=ALL-UNNAMED
and then it doesn't work / the tcp connections fail
Diagnosis
Code not working without changes
Therapy
Surprise - stay with Java 8 ...
Incompatible Javadoc
Problem
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-javadoc-plugin:3.0.1:jar (attach-javadocs) on project com.bitplan.rest.freemarker: MavenReportException: Error while generating Javadoc: [ERROR] Exit code: 1 - javadoc: error - The code being documented uses modules but the packages defined in https://docs.oracle.com/javase/8/docs/api/ are in the unnamed module. [ERROR] [ERROR] Command line was: /usr/local/lib/jvm/openjdk11/bin/javadoc -Xdoclint:none @options @packages
Diagnosis
java -Xmx32m -version
openjdk version "11.0.2" 2019-01-15
Java 11 javadoc is incompatible to prior versions
Therapy
Surprise - stay with Java 8 ...
mvn site fails
Problem
org.apache.bcel.classfile.ClassFormatException: Invalid byte tag in constant pool: 19
at org.apache.bcel.classfile.Constant.readConstant (Constant.java:161)
Diagnosis
- https://stackoverflow.com/questions/49383179/org-apache-bcel-classfile-classformatexception-invalid-byte-tag-in-constant-poo
- upgrading maven site plugin to https://mvnrepository.com/artifact/org.apache.maven.plugins/maven-site-plugin/3.9.0 does not help