OpenJDK

1、首先去官网下载jdk https://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html 2、检查当前系统是否已经安装openJDK，如果已经安装进行卸载 检查openJDK是否安装命令：rpm -qa|grep jdk (如果有安装openJDK 那么除了copy-jdk-configs-3.3-2.el7.noarch文件可以不用删除。其他的openJdk全部要卸载) 卸载命令：yum -y remove xxxx 3、进入目录 : cd /usr/local 4、创建java安装目录： mkdir /usr/local/java 5、解压安装包到 /usr/local/java目录： tar -zxvf jdk-8u162-linux-x64.tar.gz /usr/local/java 6、配置jdk环境变量： 编辑/etc/下的profile文件： vi /etc/profile 在文件末尾添加如下配置： export JAVA_HOME=/usr/local/java/jdk1.8.0_162 export JRE_HOME=${JAVA_HOME}/jre export CLASSPATH=.:${JAVA_HOME}/lib:${JRE_HOME}/lib

I know about the -XX:+HeapDumpOnOutOfMemoryError JVM parameter. I also know about -XX:OnOutOfMemoryError="cmd args;cmd args" and that kill -3 <JVM_PID> will request a heap dump. Question: How can I make sure that I, on OutOfMemoryError , first make a full heap dump and then force a restart (or kill) after the dump is done? Is my best bet -XX:OnOutOfMemoryError="kill -3 %p;sleep <time-it-takes-to-dump>;kill -9 %p" ? java -XX:+HeapDumpOnOutOfMemoryError -XX:OnOutOfMemoryError="kill -9 %p" TestApp JVM will dump heap first, and then execute OnOutOfMemoryError commands (proof) . If you just want to

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I try to install Pycharm on Ubuntu 12.04 and I have this information: user@user:~/Pobrane/pycharm-2.5.2/bin$ sh pycharm.sh OpenJDK Runtime Environment (IcedTea6 1.11.1) (6b24-1.11.1-4ubuntu3) OpenJDK Server VM (build 20.0-b12, mixed mode) WARNING: You are launching the IDE using OpenJDK Java runtime. ITS KNOWN TO HAVE PERFORMANCE AND GRAPHICS ISSUES! SWITCH TO THE ORACLE(SUN) JDK BEFORE REPORTING PROBLEMS! NOTE: If you have both Oracle (Sun) JDK and OpenJDK installed please validate either PYCHARM_JDK, JDK_HOME, or JAVA_HOME environment

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: Help! I can't figure out how to install a jdk! [/usr/lib/jvm]$ su -c "yum install java-1.7.0-openjdk-devel" Loaded plugins: langpacks, presto, refresh-packagekit No package java-1.7.0-openjdk-devel available. Error: Nothing to do [/usr/lib/jvm]$ su -c "yum install java-1.7.0-openjdk" Loaded plugins: langpacks, presto, refresh-packagekit No package java-1.7.0-openjdk available. Error: Nothing to do [/usr/lib/jvm]$ su -c "yum install java-1.6.0-openjdk-devel" Loaded plugins: langpacks, presto, refresh-packagekit No package java-1.6.0-openjdk

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I wrote the following Java program to dump the enabled ciphers in the JVM: import java.security.KeyStore; import javax.net.ssl.KeyManagerFactory; import javax.net.ssl.SSLContext; import javax.net.ssl.SSLSocket; import javax.net.ssl.TrustManagerFactory; public class ListCiphers { public static void main(String[] args) throws Exception { SSLContext ctx = SSLContext.getInstance("TLSv1"); // Create an empty TrustManagerFactory to avoid loading default CA KeyStore ks = KeyStore.getInstance("JKS"); TrustManagerFactory tmf = TrustManagerFactory

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: When starting jetty-distribution-9.3.0.v20150612 with openjdk 1.8.0_51 running on an EC2 Amazon Linux machine, is prints that all configured ECDHE suites are not supported. 2015-08-12 16:51:20 main SslContextFactory [INFO] Cipher TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256 not supported 2015-08-12 16:51:20 main SslContextFactory [INFO] Cipher TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256 not supported 2015-08-12 16:51:20 main SslContextFactory [INFO] Cipher TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 not supported 2015-08-12 16:51:20 main

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I've never worked with Maven before and I am following the instructions here. When I run the command mvn integration-test -Pamp-to-war It initially downloaded a whole bunch of dependencies, and in the end it showed, COMPILATION ERROR : [INFO] ------------------------------------------------------------- [ERROR] No compiler is provided in this environment. Perhaps you are running on a JRE rather than a JDK? [INFO] 1 error I am on ubuntu 13.04. If there's anything you want me to tell you, let me know. Thanks. EDIT When I do echo $JAVA_HOME I

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 由 翻译 强力驱动 问题: I am facing the problem while running the java program from command line. I have openjdk-6-jdk installed in my linux system and still shows the error relates with the openjdk-7-jdk. Initially i have jdk 7 installed in my system but ater i have removes it but still facing problem while running the application. after running the cammand sudo update - alternatives -- config java it shows warning as follows update-alternatives: warning: /etc/alternatives/java is dangling, it will be updated with best choice. There is only one

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I'm trying to run some JavaFX code with Eclipse Kepler, with e(fx)clipse plugin installed, on a Linux machine, using: java version "1.7.0_21" OpenJDK Runtime Environment (IcedTea 2.3.9) (7u21-2.3.9-5) OpenJDK 64-Bit Server VM (build 23.7-b01, mixed mode) My understanding is that although JavaFX has been included with the standard JDK since version JDK 7u6, the JavaFX runtime JAR file, jfxrt.jar, was left off of the Java runtime path on purpose until further testing between JavaFX and rest of the java infrastructure has been completed. For