ubuntu安装Eclipse

1. 版本

   • ubuntu16.04 64bit
   • Eclipse 2019-12 （太高容易崩溃）

     下载：wget https://archive.eclipse.org/technology/epp/downloads/release/2019-12/R/eclipse-java-2019-12-R-linux-gtk-x86_64.tar.gz
     

2. jdk安装

   • 将jdk1.8.0_211-linux-x64.tar.gz解压到/opt下
   • 添加环境变量 vi ~/.bashrc

     export JAVA_HOME=/opt/jdk1.8.0_211
     export CLASSPATH=$CLASSPATH:$JAVA_HOME/lib:$JAVA_HOME/jre/lib
     export PATH=$PATH:$JAVA_HOME/bin:$JAVA_HOME/jre/bin:$HOME/bin
     

3. eclipse安装

   • 将eclipse-java-2019-12-R-linux-gtk-x86_64.tar.gz解压到/opt下
   • 添加桌面图标
     • cd /usr/share/applications
     • sudo touch eclipse.desktop
     • sudo vim eclipse.desktop

       [Desktop Entry]
       Encoding=UTF-8
       Name=Eclipse
       Comment=Eclipse
       Exec=/opt/eclipse/eclipse
       Icon=/opt/eclipse/icon.xpm
       Terminal=false
       StartupNotify=true
       Type=Application
       Categories=Application;Development;
       

     • sudo chmod u+x eclipse.desktop
     • cp -d eclipse.desktop ~/

4. eclipse找到jdk

   • cd /opt/eclipse
   • sudo ln -s /opt/jdk1.8.0_211/jre jre

5. 使用时问题和解决方案

   • 问题：Exception in thread “main” java.lang.UnsupportedClassVersionError: com/shanlitech/echat/App has been compiled by a more recent version of the Java Runtime (class file version 53.0), this version of the Java Runtime only recognizes class file versions up to 52.0
     解决方案：运行时eclipse内部是的jre版本比编译时使用的java高。左框项目–右击–Properties–Java Compiler–Compiler compliance level–改为和编译时sdk一样的版本
   • 问题：Unbound classpath container:JRE System Library[JavaSE-9] in project
     解决方案：左框项目–右击–Properties–Java Build Path—Libraries—将报错的库版本移除