APR(Apache Portable Runtime)是一个高可移植库，它是Apache HTTP Server 2.x的核心。
APR有很多用途，包括访问高级IO功能(例如sendfile,epoll和OpenSSL)，OS级别功能(随机数生成，系统状态等等)，本地进程管理(共享内存，NT管道和UNIX sockets)。这些功能可以使Tomcat作为一个通常的前台WEB服务器，能更好地和其它本地web技术集成，总体上让Java更有效率作为一个高性能web服务器平台而不是简单作为后台容器。在Tomcat中使用JNI的方式来读取文件以及进行网络传输。这个东西可以大大提升Tomcat对静态文件的处理性能，同时如果你使用了HTTPS方式 传输的话，也可以提升SSL的处理性能。
安装过程
1. 下载所需的安装包
到http://apr.apache.org/下载apr-1.5.2.tar.gzapr-iconv-1.2.1.tar.gzapr-util-1.5.4.tar.gz
到http://archive.apache.org/dist/tomcat/tomcat-connectors/native/下载tomcat-native-1.1.33-src.tar.gz
2. 安装依次安装 apr, apr-iconv, apr-util, tomcat-nativetomcat-native的安装参数可以参考 http://tomcat.apache.org/native-doc/
tar zxvf apr-1.5.2.tar.gz cd apr-1.5.2./configure --prefix=/usr/local/share/aprsudo makesudo make installtar zxvf apr-iconv-1.2.1.tar.gz cd apr-iconv-1.2.1./configure --prefix=/usr/local/share/apr-iconv --with-apr=/usr/local/share/aprsudo makesudo make installtar zxvf apr-util-1.5.4.tar.gz cd apr-util-1.5.4./configure --prefix=/usr/local/share/apr-util --with-apr=/usr/local/share/apr --with-apr-iconv=/usr/local/share/apr-iconv/bin/apriconv sudo makesudo make installtar zxvf tomcat-native-1.1.33-src.tar.gz cd tomcat-native-1.1.33-src/jni/native/./configure --with-apr=/usr/local/share/apr --with-java-home=/usr/java/jdk1.6.0_45 --prefix=/opt/tomcatsudo makesudo make install
注意, 最后一步指定了tomcat-native的安装路径是tomcat的安装目录, 而且安装结果会提示你
Libraries have been installed in: /opt/tomcat/libIf you ever happen to want to link against installed librariesin a given directory, LIBDIR, you must either use libtool, andspecify the full pathname of the library, or use the `-LLIBDIR'flag during linking and do at least one of the following: - add LIBDIR to the `LD_LIBRARY_PATH' environment variable during execution - add LIBDIR to the `LD_RUN_PATH' environment variable during linking - use the `-Wl,-rpath -Wl,LIBDIR' linker flag - have your system administrator add LIBDIR to `/etc/ld.so.conf'
所以你要把这个放到系统路径里
sudo vi /etc/profileAdd to last lineexport LD_LIBRARY_PATH=/opt/tomcat/lib
保存之后, 在启动tomcat的用户环境下 source /etc/profile, 然后重启tomcat. 安装成功时, tomcat的启动日志会显示类似这样的信息
May 16, 2015 11:32:12 PM org.apache.catalina.core.AprLifecycleListener initINFO: Loaded APR based Apache Tomcat Native library 1.1.33 using APR version 1.5.2.May 16, 2015 11:32:12 PM org.apache.catalina.core.AprLifecycleListener initINFO: APR capabilities: IPv6 [true], sendfile [true], accept filters [false], random [true].May 16, 2015 11:32:13 PM org.apache.coyote.AbstractProtocol initINFO: Initializing ProtocolHandler ["http-apr-8080"]