The Apache Tomcat Native library which allows using OpenSSL was not found on the java.library.path: [/usr/java/packages/lib/amd64:/usr/lib64:/lib64:/lib:/usr/lib]

tomcat启动项目时出现“org.apache.catalina.core.AprLifecycleListener.lifecycleEvent The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: [/usr/java/packages/lib/amd64:/usr/lib64:/lib64:/lib:/usr/lib]”错误，有些时候不影响项目的启动。如下图所示：

Tomcat支持三种接收请求的处理方式：BIO、NIO、APR

1. BIO由于每个请求都要创建一个线程来处理，线程开销比较大，不能再高并发的场景，性能也是最低的。

2. NIO是一个基于缓冲区、并能提供非阻塞I/O操作的Java API，比传统的bio更好的并发性能。

3. APR（Apache Portable Run-time libraries）简单理解，就是从操作系统级别解决异步IO问题。

所需软件

 apr apr-iconv  apr-util  tomcat-native

安装软件

yum install -y apr-devel openssl-devel gcc make expat-devel libtool

cd /usr/local/src

wget https://mirrors.cnnic.cn/apache/apr/apr-1.6.3.tar.gz tar xf apr-1.6.3.tar.gz

cd apr-1.6.3/ ./configure --prefix=/usr/local/apr

make && make install

cd /usr/local/src

wget https://mirrors.cnnic.cn/apache/apr/apr-iconv-1.2.2.tar.gz

tar xf apr-iconv-1.2.2.tar.gz cd apr-iconv-1.2.2/ ./configure --with-apr=/usr/local/apr --prefix=/usr/local/apr-iconv

make && make install

cd /usr/local/src

wget https://mirrors.cnnic.cn/apache/apr/apr-util-1.6.1.tar.gz tar xf apr-util-1.6.1.tar.gz cd apr-util-1.6.1/ ./configure --prefix=/usr/local/apr-util --with-apr=/usr/local/apr --with-apr-iconv=/usr/local/apr-iconv/bin/apriconv

make && make install

cd /usr/local/tomcat/bin/ tar xf tomcat-native.tar.gz cd /usr/local/tomcat/bin/tomcat-native-1.2.16-src/native ./configure --with-apr=/usr/local/apr --with-java-home=/usr/local/jdk8.0

make && make install

echo ‘export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/apr/lib

export LD_RUN_PATH=$LD_RUN_PATH:/usr/local/apr/lib‘ >> /etc/profile source /etc/profile

使用命令“vi /etc/profile”打开环境配置文件后，将其拖到底部，在profile文件中添加“export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/apr/lib”。如下图所示：