在一般的java项目中，如果在linux中实现进程在后台执行比较简单，可以采用nohup cmd 或者sh cmd &等多种方式实现，进行在后台执行。但是在window操作系统中就比较困难了，需要实现相关的类。如在tomcat，jboss的启动之后，端口一直开放着。
常用实现方式实现Commons-Daemon中的Daemon接口实现相关的方式，使用相关的bat，命令启动。在Commons-Deamon调用jsvc实现。
在activemq.bat中相关bat命令如下：
"%_JAVACMD%" %SUNJMX% %ACTIVEMQ_DEBUG_OPTS% %ACTIVEMQ_OPTS% %SSL_OPTS% -Dactivemq.classpath="%ACTIVEMQ_CLASSPATH%" -Dactivemq.home="%ACTIVEMQ_HOME%" -Dactivemq.base="%ACTIVEMQ_BASE%" -jar "%ACTIVEMQ_HOME%/bin/run.jar" start %*
备注：在run.jar包中Main方法调用 ActiveMQLauncher 实现相关的功能。
Starting jsvc
To check the allowed parameters for the jsvc binary simply do:
./jsvc -help
Usage: jsvc [-options] class [args...]
Where options include:
-help | --help | -?
show this help page (implies -nodetach)
-jvm
use a specific Java Virtual Machine. Available JVMs:
'client' 'server'
-cp / -classpath
set search path for service classes and resouces
-home
set the path of your JDK or JRE installation (or set
the JAVA_HOME environment variable)
-version
show the current Java environment version (to check
correctness of -home and -jvm. Implies -nodetach)
-showversion
show the current Java environment version (to check
correctness of -home and -jvm) and continue execution.
-nodetach
don't detach from parent process and become a daemon
-debug
verbosely print debugging information
-check
only check service (implies -nodetach)
-user
user used to run the daemon (defaults to current user)
-verbose[:class|gc|jni]
enable verbose output
-outfile
Location for output from stdout (defaults to /dev/null)
Use the value '&2' to simulate '1>&2'
-errfile
Location for output from stderr (defaults to /dev/null)
Use the value '&1' to simulate '2>&1'
-pidfile
Location for output from the file containing the pid of jsvc
(defaults to /var/run/jsvc.pid)
-D=
set a Java system property
-X
实际上仅支持类UNIX平台。源代码在A src/native/unix subdirectory子目录。在将来将利用APR来提供更方便的平台支持。
从源代码构建
在UNIX系统下构建你需要：
● GNU AutoConf (最低版本 2.53)
● 一个ANSI-C兼容的编译器 (推荐GCC)
● GNU Make
● JAVA2平台兼容的SDK
你需要构建 "configure" 程序:
sh support/buildconf.sh
结果类似如下:
support/buildconf.sh
support/buildconf.sh: configure script generated successfully
一旦生成了configure脚本，可进行后续步骤。
从一个发布版中构建
在UNIX系统下构建你需要：
● 一个ANSI-C兼容的编译器 (推荐GCC)
● GNU Make
● JAVA2平台兼容的SDK
你必须指定JAVA_HOME或者使用 --with-java=
./configure --with-java=/usr/java
或者
export JAVA_HOME
./configure
如果你的操作系统支持，configure会顺利运行，否则会报错。构建二进制程序和库：
make
这个生成可执行文件jsvc。
启动 jsvc
查看可用的jsvc参数仅需:
./jsvc -help
Usage: jsvc [-options] class [args...]
Where options include:
-jvm
use a specific Java Virtual Machine. Available JVMs: 'client' 'server'
-cp / -classpath
set search path for service classes and resouces
-home
设置JDK或者JRE的安装路径 (或者设置 JAVA_HOME 环境变量)
-version
show the current Java environment version (to check correctness of -home and -jvm. Implies -nodetach)
-help / -?
显示帮助信息 (implies -nodetach)
-nodetach
don't detach from parent process and become a daemon
-debug
详细输出调试信息
-check
only check service (implies -nodetach)
-user
运行守护程序的用户(默认是当前用户)
-verbose[:class|gc|jni]
启用详细输出
-outfile
Location for output from stdout (defaults to /dev/null) Use the value '&2' to simulate '1>&2'
-errfile
Location for output from stderr (defaults to /dev/null) Use the value '&1' to simulate '2>&1'
-pidfile
jsvc的pid文件位置(默认 /var/run/jsvc.pid)
-D
设置java系统的属性
-X
如在ActiveMQ中启动类如下：
package org.apache.activemq.console;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import org.apache.activemq.console.command.Command;
import org.apache.activemq.console.command.ShutdownCommand;
import org.apache.activemq.console.command.StartCommand;
import org.apache.activemq.console.CommandContext;
import org.apache.activemq.console.Main;
import org.apache.activemq.console.formatter.CommandShellOutputFormatter;
import org.apache.commons.daemon.Daemon;
import org.apache.commons.daemon.DaemonContext;
/**
* This class launches activemq under Apache JSVC {@link http://commons.apache.org/daemon/jsvc.html}
*
* @author areese
*
*/
public class ActiveMQLauncher implements Daemon {
private List args;
/**
*
*/
public ActiveMQLauncher() {
}
/*
* (non-Javadoc)
*
* @see org.apache.commons.daemon.Daemon#destroy()
*/
public void destroy() {
}
/*
* (non-Javadoc)
*
* @see
* org.apache.commons.daemon.Daemon#init(org.apache.commons.daemon.DaemonContext
* )
*/
public void init(DaemonContext arg0) throws Exception {
// we need to save the args we started with.
args = Arrays.asList(arg0.getArguments());
}
/*
* (non-Javadoc)
*
* @see org.apache.commons.daemon.Daemon#start()
*/
public void start() throws Exception {
CommandContext context = new CommandContext();
context.setFormatter(new CommandShellOutputFormatter(System.out));
Command command = new StartCommand();
command.setCommandContext(context);
command.execute(args);
}
/*
* (non-Javadoc)
*
* @see org.apache.commons.daemon.Daemon#stop()
*/
public void stop() throws Exception {
CommandContext context = new CommandContext();
context.setFormatter(new CommandShellOutputFormatter(System.out));
Command command = new ShutdownCommand();
command.setCommandContext(context);
List tokens = new ArrayList(Arrays.asList(new String[] {
"--jmxlocal", "--all", }));
command.execute(tokens);
}
}
Daemon that implements the following methods:
- void init(String[] arguments): Here open configuration files, create a trace file, create ServerSockets, Threads
- void start(): Start the Thread, accept incoming connections
- void stop(): Inform the Thread to terminate the run(), close the ServerSockets
void destroy(): Destroy any object created in init()