java 有没有办法从 build.xml 中指定本地 jsch.jar 的位置？
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Is there a way to specify the location of a local jsch.jar from within build.xml?
提问by Tomasz
build.xml contains <scp>and <sshexec>tasks, so I provide jsch.jar and
other libraries in the same directory together with build.xml.
build.xml 包含<scp>和<sshexec>tasks，所以我把jsch.jar 等库和build.xml 放在同一个目录下。
The following taskdef:
以下任务定义：
<taskdef name="scp"
classname="org.apache.tools.ant.taskdefs.optional.ssh.Scp"
classpath="WebContent/WEB-INF/lib/jsch-0.1.43.jar" />
throws an error
抛出错误
A class needed by class org.apache.tools.ant.taskdefs.optional.ssh.Scp
cannot be found: com/jcraft/jsch/UserInfo
I cannot modify the standard Ant installation (e.g. put jsch.jar in ant lib directory, or remove ant-jsch.jar), or add command-line flags, or modify system environment variables, etc.: the script has to run with default Ant on different systems.
我无法修改标准的 Ant 安装（例如将 jsch.jar 放在 ant lib 目录中，或删除 ant-jsch.jar），或添加命令行标志，或修改系统环境变量等：脚本必须以默认方式运行不同系统上的蚂蚁。
I'm actually reposting the question originally asked here: http://ant.1045680.n5.nabble.com/specifying-location-of-an-external-library-within-build-xml-td1344969.html
我实际上是在重新发布最初在这里提出的问题：http: //ant.1045680.n5.nabble.com/specifying-location-of-an-external-library-within-build-xml-td1344969.html
but could not get the answer about classloader to work.
但无法得到有关类加载器工作的答案。
回答by igor
Finally I found a working solution (for Ant 1.7.1 at least). First you have to remove ant-jsch.jarfrom ANT_HOME/libas Ant complains about it and gets confused. Then load libraries from the project itself:
最后我找到了一个可行的解决方案（至少对于 Ant 1.7.1）。首先，您必须ant-jsch.jar从ANT_HOME/libAnt 抱怨它并感到困惑时将其删除。然后从项目本身加载库：
<available property="ant-jsch.present" file="${ant.home}/lib/ant-jsch.jar"/>
<fail if="ant-jsch.present" message="Please remove ant-jsch.jar from ANT_HOME/lib see [http://ant.apache.org/faq.html#delegating-classloader]"/>
<path id="jsch.path">
<pathelement location="lib/ant-jsch.jar" />
<pathelement location="lib/jsch-0.1.44.jar" />
</path>
<taskdef name="scp" classname="org.apache.tools.ant.taskdefs.optional.ssh.Scp" classpathref="jsch.path" />
<taskdef name="sshexec" classname="org.apache.tools.ant.taskdefs.optional.ssh.SSHExec" classpathref="jsch.path" />
回答by Marcond
So, this question is old, but I devised another approach which may help others. We can spawn Ant from a <java>task with the proper classpath to run <scp>. This avoid the classpath leaking problem, and doesn't requires changing Ant install in any way:
所以，这个问题很旧，但我设计了另一种可能对其他人有帮助的方法。我们可以从<java>具有正确类路径的任务中生成 Ant来运行<scp>。这避免了类路径泄漏问题，并且不需要以任何方式更改 Ant 安装：
<target name="sendfile">
<!-- file: local file to send -->
<!-- todir: remote directory -->
<java classname="org.apache.tools.ant.launch.Launcher"
fork="true" dir="${basedir}" taskname="ant+scp">
<classpath>
<pathelement location="/where/is/jsch-0.1.49.jar"/>
<pathelement location="${ant.home}/lib/ant-launcher.jar"/>
</classpath>
<arg value="-buildfile"/>
<arg file="${ant.file}"/>
<arg value="-Dfile=${file}"/>
<arg value="-Dtodir=${todir}"/>
<arg value="sendfile.scp"/>
</java>
</target>
<target name="sendfile.scp">
<echo message="Sending ${file} to ${todir}"/>
<property file="/tmp/passwordfile"/>
<scp file="${file}" todir="[email protected]:${todir}"
trust="true" port="22" password="${PASSWORD}"/>
</target>
The portparameter isn't needed, but it's here as a reminder for custom SSH ports. The password is a property stored on /tmp/passwordfile, like PASSWORD=mysecretpassword. Change these to suit your needs. Here follows an usage example:
该port参数不是必需的，但它在这里是为了提醒自定义 SSH 端口。密码是存储在 上的属性/tmp/passwordfile，例如PASSWORD=mysecretpassword。更改这些以满足您的需求。下面是一个使用示例：
<ant target="sendfile">
<!-- Example: send /etc/os-release file to remote dir /home/myself -->
<property name="file" value="/etc/os-release"/>
<property name="todir" value="/home/myself"/>
</ant>
回答by Mark Slater
For reference, an approach that I find useful is to repackage the jars, so they don't conflict - you can do this in Ant using JarJar like this:
作为参考，我发现一种有用的方法是重新打包 jar，这样它们就不会发生冲突 - 您可以在 Ant 中使用 JarJar 执行此操作，如下所示：
<taskdef name="jarjar" classname="com.tonicsystems.jarjar.JarJarTask" classpath="${basedir}/lib/build/jar/jarjar-1.4.jar"/>
<taskdef name="scp" classname="repackaged.scp.org.apache.tools.ant.taskdefs.optional.ssh.Scp" classpath="${basedir}/lib/build/jar/repackaged-scp.jar"/>
<target name="repackage.scp" description="Repackages Ant's optional SCP task and the JSch implementation to avoid conflicting with one on Ant's classpath">
<delete file="${basedir}/lib/build/jar/repackaged-scp.jar" failonerror="false"/>
<jarjar basedir="." jarfile="${basedir}/lib/build/jar/repackaged-scp.jar" includes="nothing">
<zipfileset src="${basedir}/lib/build/jar/ant-jsch-1.9.1.jar"/>
<zipfileset src="${basedir}/lib/build/jar/jsch-0.1.50.jar"/>
<rule pattern="com.jcraft.jsch.**" result="repackaged.scp.com.jcraft.jsch.@1"/>
<rule pattern="org.apache.tools.ant.taskdefs.optional.ssh.**" result="repackaged.scp.org.apache.tools.ant.taskdefs.optional.ssh.@1"/>
</jarjar>
</target>
回答by user3499805
I was able to solve this issue following post from here https://stackoverflow.com/a/858744/3499805and then
我能够在https://stackoverflow.com/a/858744/3499805 的帖子之后解决这个问题 ，然后
<taskdef resource="net/jtools/classloadertask/antlib.xml" classpath="${basedir}/ant-lib/ant-classloadertask.jar" />
<classloader loader="system" classpath="${basedir}/ant-lib/jsch-0.1.54.jar"/>
回答by basin
There's a well-known trickwith URLClassLoader. By using it we can make jschaccessible to ant-jsch.
有一个众所周知的伎俩用URLClassLoader。通过使用它，我们可以jsch访问ant-jsch.
I wonder how classloadertaskfrom the answer by @user3499805 works.
我想知道classloadertask@user3499805 的回答是如何工作的。
<target name="injectJsch" description="inject jsch jar">
<makeurl file="${acdc.java.tools}/lib/jsch-0.1.50.jar" property="jsch.jar.url"/>
<taskdef name="injectJsch"
classname="tools.deployments.ant.InjectJsch"
classpath="${basedir}/jars/ajwf_deploytools.jar"
/>
<injectJsch jarLocation="${jsch.jar.url}"/>
</target>
_
_
package tools.deployments.ant;
import java.lang.reflect.Method;
import java.net.URL;
import java.net.URLClassLoader;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.Task;
import org.apache.tools.ant.taskdefs.optional.ssh.LogListener;
public class InjectJsch extends Task {
public void setJarLocation(final String jarLocation) {
this.jarLocation = jarLocation;
}
@Override
public void execute() throws BuildException {
try {
injectJsch(new URL(jarLocation));
} catch (final Exception e) {
throw new BuildException(e);
}
}
public static void injectJsch(final URL jarLocation) throws Exception {
ClassLoader parent = LogListener.class.getClassLoader();
try {
parent.loadClass(TESTCLASS);
} catch (final ClassNotFoundException e) {
final Method addURLmethod = URLClassLoader.class.getDeclaredMethod("addURL", URL.class);
addURLmethod.setAccessible(true);
ClassLoader cl;
do {
cl = parent;
if (cl instanceof URLClassLoader) {
addURLmethod.invoke(cl, jarLocation);
break;
}
parent = cl.getParent();
} while (parent != cl && parent != null);
LogListener.class.getClassLoader().loadClass(TESTCLASS);
}
}
private String jarLocation;
private static final String TESTCLASS = "com.jcraft.jsch.UserInfo";
}
回答by Mark O'Connor
Create a path reference and then use it in your task definition:
创建一个路径引用，然后在您的任务定义中使用它：
<path id="ssh.path">
<pathelement location="${lib1.dir}/helloworld.jar"/>
<fileset dir="${lib2.dir}">
<include name="*.jar"/>
</fileset>
</path>
<taskdef name="mytask" classname="org.mytask" classpathref="ssh.path" />
回答by Ed Randall
Create ~/.ant/liband copy jsch.jarin there as part of the build initialisation.
作为构建初始化的一部分，在那里创建~/.ant/lib和复制jsch.jar。
<target name="init">
<property name="user.ant.lib" location="${user.home}/.ant/lib"/>
<mkdir dir="${user.ant.lib}"/>
<copy todir="${user.ant.lib}">
<fileset dir="${basedir}/build/tools" includes="jsch-*.jar"/>
</copy>
</target>
