The JRE you are running Eclipse with appears to not be a JDK .Spring Boot Live hovers will not work with a plain JREjavascript
** 由于以前安装java时,先装了 java 11,后来装了Java8 ** Eclipse运行是须要一个JRE(后来才知道有一个ini 配置文件) ** 这个JRE并非系统环境变量中的javac目录下的JRE ** 而是JDK安装时候自带的JRE目录,此目录下并没有javachtml
Window > Preferences > Java > Installed JREs > Execution Environments ** 确认已经设置为 java 8 了!并非 java 11!
** 单独对项目 property ,也都是 java 8 !java
sudo update-alternatives --config java 再次选择一下 java 版本 而后 open 刚才 close 的 project。再次 restart eclipse,好像就不出错了! 可是,退出去再来!仍是那个错误!ubuntu
1. 查看全部 jdk 安装版本 sudo update-java-alternatives -l 返回结果以下: java-1.11.0-openjdk-amd64 1101 /usr/lib/jvm/java-1.11.0-openjdk-amd64 java-1.8.0-openjdk-amd64 1081 /usr/lib/jvm/java-1.8.0-openjdk-amd64 2. 删除 jdk 1.11。0 sudo apt-get remove java-1.11.0-openjdk-amd64sudo apt-get remove java-1.11.0-openjdk-amd64 [sudo] password for dhbm: Reading package lists... Done Building dependency tree Reading state information... Done E: Unable to locate package java-1.11.0-openjdk-amd64 E: Couldn't find any package by glob 'java-1.11.0-openjdk-amd64' E: Couldn't find any package by regex 'java-1.11.0-openjdk-amd64' ** 包名不叫这个啊! 3.参考 ubuntu 命令行卸载并清理软件
https://blog.csdn.net/hanshileiai/article/details/46972869 ubuntu如何彻底卸载Java https://blog.csdn.net/w2222288/article/details/53887071app
4. 查找 java ,里面没有 jdk 1.11 dpkg --get-selections | grep java ca-certificates-java install gir1.2-javascriptcoregtk-4.0:amd64 install java-common install libatk-wrapper-java install libatk-wrapper-java-jni:amd64 install libjavascriptcoregtk-4.0-18:amd64 install 5. 查找 jdk dpkg --get-selections | grep jdk openjdk-11-jre:amd64 install openjdk-11-jre-headless:amd64 install openjdk-8-jdk:amd64 install openjdk-8-jdk-headless:amd64 install openjdk-8-jre:amd64 install openjdk-8-jre-headless:amd64 install 找到了! 6. 移除 jdk 11 sudo apt-get remove openjdk-11-jre:amd64 sudo apt-get remove openjdk-11-jre-headless:amd64 7. 清理残留数据 dpkg -l |grep ^rc|awk '{print $2}' |sudo xargs dpkg -P (Reading database ... 168839 files and directories currently installed.) Purging configuration files for openjdk-11-jre-headless:amd64 (10.0.2+13-1ubuntu0.18.04.4) ... 而后,sudo reboot!
** 完蛋了!仍是指向了 java 11 !怎么办? ** 重装 Eclipse,再启动,仍是以上错误啊! ** 由于我并无卸载 Eclipse,直接覆盖安装的!因此才想到,Eclipse 本身应该有配置文件!(删除 java 11 以前想到就行了!)less
cd /home/dhbm/Desktop/eclipse2019 ls configuration eclipse eclipse.ini.bak icon.xpm META-INF plugins dropins eclipse.ini epl-v10.html license.txt notice.html readme
真的是有 configuration,还有eclipse.ini,打开eclipse.ini,原来问题在这里啊! eclipse
把这里改为 java 8 ,OK! -vm /usr/lib/jvm/java-8-openjdk-amd64/bin ** 再次抄录一下以前的学习记录,由于过程当中可能删除了桌面快捷! 建立 Eclipse 桌面快捷 先去图形界面下找到 eclipse ,复制路径 /home/dhbm/eclipse/java-2018-12/eclipse ** Ubuntu 中文版 ln -s ~/eclipse/jee-2018-12/eclipse ~/桌面/eclipse2019 ln -s ~/eclipse/jee-2018-12/eclipse/eclipse ~/桌面/eclipse201901 ** Ubuntu 英文版 ln -s /home/dhbm/eclipse/java-2018-12/eclipse /home/dhbm/Desktop/eclipse2019 ln -s /home/dhbm/eclipse/java-2018-12/eclipse/eclipse ~/Desktop/ecli