blocks|key|156869|text|我想通了。主要问题是，当Gradle派生一个新的Java进程时，它不会自动将环境变量值传递给新环境。必须通过任务或插件的systemProperties属性显式传递这些变量。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|156870|另一个问题是理解如何传递命令行参数；这些参数是通过任务或插件的args属性实现的。与Maven+exec-maven-plugin一样，它们应该通过另一个系统属性在命令行上传递，作为一个空格分隔的列表，然后在设置接受List对象的args之前需要对其进行split()。我已经将该属性命名为exec.args，这是旧的maven名。|156871|似乎javaExec和应用程序插件的方法都是有效的。如果想要使用应用程序插件的一些其他特性(自动将发行版放在一起等)，可能会更喜欢应用程序插件方法。|156872|以下是解决方案：|156873|JavaExec方法|156874|命令行|BOLD|156875|gradle+execute+-Dmyvariable=myvalue+-Dexec.args="arg1+arg2+arg3"|code-block|syntax|javascript|156876|build.gradle|156877|task+execute+(type:JavaExec)+{

++++main+=+"com.myCompany.MyMain"
++++classpath+=+sourceSets.main.runtimeClasspath+

++++/*+Can+pass+all+the+properties:+*/
++++systemProperties+System.getProperties()

++++/*+Or+just+each+by+name:+*/
++++systemProperty+"myvariable",+System.getProperty("myvariable")

++++/*+Need+to+split+the+space-delimited+value+in+the+exec.args+*/
++++args+System.getProperty("exec.args",+"").split()++++
}|156878|应用程序插件方法|156879|156880|gradle+run+-Dmyvariable=myvalue+-Dexec.args="arg1+arg2+arg3"|156881|156882|apply+plugin:+'application'
mainClassName+=+"com.mycompany.MyMain"
run+{++++
++++/*+Can+pass+all+the+properties:+*/
++++systemProperties+System.getProperties()

++++/*+Or+just+each+by+name:+*/
++++systemProperty+"myvariable",+System.getProperty("myvariable")

++++/*+Need+to+split+the+space-delimited+value+in+the+exec.args+*/
++++args+System.getProperty("exec.args",+"").split()++++
}|156883|entityMap^0|1O|G|0|V|4|1C|H|30|4|37|4|3J|7|41|9|0|2|8|0|0|0|0|3|0|0|0|C|0|0|0|0|3|0|0|0|C|0|0^^$0|@$1|2|3|4|5|6|7|19|8|@$9|1A|A|1B|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|1C|8|@$9|1D|A|1E|B|C]|$9|1F|A|1G|B|C]|$9|1H|A|1I|B|C]|$9|1J|A|1K|B|C]|$9|1L|A|1M|B|C]|$9|1N|A|1O|B|C]]|D|@]|E|$]]|$1|H|3|I|5|6|7|1P|8|@$9|1Q|A|1R|B|C]]|D|@]|E|$]]|$1|J|3|K|5|6|7|1S|8|@]|D|@]|E|$]]|$1|L|3|M|5|6|7|1T|8|@]|D|@]|E|$]]|$1|N|3|O|5|6|7|1U|8|@$9|1V|A|1W|B|P]]|D|@]|E|$]]|$1|Q|3|R|5|S|7|1X|8|@]|D|@]|E|$T|U]]|$1|V|3|W|5|6|7|1Y|8|@$9|1Z|A|20|B|P]]|D|@]|E|$]]|$1|X|3|Y|5|S|7|21|8|@]|D|@]|E|$T|U]]|$1|Z|3|10|5|6|7|22|8|@]|D|@]|E|$]]|$1|11|3|O|5|6|7|23|8|@$9|24|A|25|B|P]]|D|@]|E|$]]|$1|12|3|13|5|S|7|26|8|@]|D|@]|E|$T|U]]|$1|14|3|W|5|6|7|27|8|@$9|28|A|29|B|P]]|D|@]|E|$]]|$1|15|3|16|5|S|7|2A|8|@]|D|@]|E|$T|U]]|$1|17|3|-4|5|6|7|2B|8|@]|D|@]|E|$]]]|18|$]]

Figured it out. The main issue is that when Gradle forks a new Java process, it does not automatically pass the environment variable values along to the new environment. One has to explicitly pass these variables via the <code>systemProperties</code> property of the task or plugin. 

The other issue was understanding how to pass command-line args; these are via the <code>args</code> property on the task or plugin. As with the Maven <code>exec-maven-plugin</code>, they should be passed in on the command line via yet another system property, as a space-delimited list that then needs to be <code>split()</code> before setting <code>args</code>, which accepts <code>List</code> objects. I've named the property <code>exec.args</code>, which is the old Maven name.

It seems both the <code>javaExec</code> and application plugin approach are valid. One might favor the application plugin approach if one wants to use some of its other features (automatically putting together a distribution, etc.)

Here are the solutions:

<h2>JavaExec Approach</h2>

Command Line:

<pre><code>gradle execute -Dmyvariable=myvalue -Dexec.args="arg1 arg2 arg3"
</code></pre>

build.gradle:

<pre><code>task execute (type:JavaExec) {

 main = "com.myCompany.MyMain"
 classpath = sourceSets.main.runtimeClasspath 

 /* Can pass all the properties: */
 systemProperties System.getProperties()

 /* Or just each by name: */
 systemProperty "myvariable", System.getProperty("myvariable")

 /* Need to split the space-delimited value in the exec.args */
 args System.getProperty("exec.args", "").split() 
}
</code></pre>

<h2>Application Plugin Approach</h2>

Command Line:

<pre><code>gradle run -Dmyvariable=myvalue -Dexec.args="arg1 arg2 arg3"
</code></pre>

build.gradle:

<pre><code>apply plugin: 'application'
mainClassName = "com.mycompany.MyMain"
run { 
 /* Can pass all the properties: */
 systemProperties System.getProperties()

 /* Or just each by name: */
 systemProperty "myvariable", System.getProperty("myvariable")

 /* Need to split the space-delimited value in the exec.args */
 args System.getProperty("exec.args", "").split() 
}
</code></pre>

blocks|key|2743196|text|对于那些可能不想通过传递无关的Gradle+prop来污染应用程序的系统属性的人，我建议使用命名空间来设置参数。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2743197|tasks.withType(JavaExec)+{
++++System.properties.each+{+k,v->
++++++++if+(k.startsWith("prefix."))+{
++++++++++++systemProperty+k+-+"prefix.",+v
++++++++}
++++}
}|code-block|syntax|javascript|2743198|java+...+-Dprefix.my.prop=true将通过my.prop|offset|length|style|CODE|2743199|entityMap^0|0|0|0|U|X|7|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@$I|R|J|S|K|L]|$I|T|J|U|K|L]]|9|@]|A|$]]|$1|M|3|-4|5|6|7|V|8|@]|9|@]|A|$]]]|N|$]]

For those who might not want to pollute your application's system properties by passing unrelated Gradle props, I recommend namespacing your arguments.

<pre><code>tasks.withType(JavaExec) {
 System.properties.each { k,v-&gt;
 if (k.startsWith("prefix.")) {
 systemProperty k - "prefix.", v
 }
 }
}
</code></pre>

<code>java ... -Dprefix.my.prop=true</code> will pass <code>my.prop</code>

blocks|key|158168|text|我是gradle的新手，所以我需要这个，而gradle+4.6对我来说在命令行中似乎更容易一些。你可以传递一个args数组，而不是解析一个arg字符串，而且我也找到了一种用一行传递所有属性的方法。组合如下：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|158169|apply+plugin:+'java'
apply+plugin:+'org.springframework.boot'++++<-+for+my+project

task+runApp(type:+JavaExec)+{
++classpath+=+sourceSets.main.runtimeClasspath

++main+=+'testit.TomcatApp'

++//+arguments+to+pass+to+the+application
++//++args+'myarg1+-rest'++++<-+came+in+as+1+string

++args+=+["--myarg1+with+spaces+even",+"--myarg2"]

++//+and+to+pass+in+all+-D+system+property+args:
++systemProperties+=+System.properties
}

gradle+run+-Dwhatever=xxx+-Dmyarg2=hey

//+Java+reading+them:
public+static+void+main(String[]+args)+{
++++for+(+int+i+=+0;+i+<+args.length;+i%2B%2B+)
++++++++{
++++++++logger.info(+"**+args+["+%2B+i+%2B+"]+="+%2B+args[i]+%2B+"="+);
++++++++}
++++logger.info(+"**+-Dwhatever+="+%2B+System.getProperty("whatever")+%2B+"="+);
++++logger.info(+"**+-Dmyarg2+="+%2B+System.getProperty("myarg2")+%2B+"="+);

[main]+INFO+testit.TomcatApp+-+**+args+[0]+=--myarg1+with+spaces+even=
[main]+INFO+testit.TomcatApp+-+**+args+[1]+=--myarg2=
[main]+INFO+testit.TomcatApp+-+**+-Dwhatever+=xxx=
[main]+INFO+testit.TomcatApp+-+**+-Dmyarg2+=hey=|code-block|syntax|javascript|158170|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

I'm new to gradle so I needed this and what is working for me with gradle 4.6 seems a little easier for the command line. Instead of parsing 1 arg string you can pass an array of args, and I found a way to pass in all property with one line as well. Combined below:

<pre><code>apply plugin: 'java'
apply plugin: 'org.springframework.boot' &lt;- for my project

task runApp(type: JavaExec) {
 classpath = sourceSets.main.runtimeClasspath

 main = 'testit.TomcatApp'

 // arguments to pass to the application
 // args 'myarg1 -rest' &lt;- came in as 1 string

 args = ["--myarg1 with spaces even", "--myarg2"]

 // and to pass in all -D system property args:
 systemProperties = System.properties
}

gradle run -Dwhatever=xxx -Dmyarg2=hey

// Java reading them:
public static void main(String[] args) {
 for ( int i = 0; i &lt; args.length; i++ )
 {
 logger.info( "** args [" + i + "] =" + args[i] + "=" );
 }
 logger.info( "** -Dwhatever =" + System.getProperty("whatever") + "=" );
 logger.info( "** -Dmyarg2 =" + System.getProperty("myarg2") + "=" );

[main] INFO testit.TomcatApp - ** args [0] =--myarg1 with spaces even=
[main] INFO testit.TomcatApp - ** args [1] =--myarg2=
[main] INFO testit.TomcatApp - ** -Dwhatever =xxx=
[main] INFO testit.TomcatApp - ** -Dmyarg2 =hey=
</code></pre>

blocks|key|154489|text|也许我在聚会上迟到了，但是有没有人尝试过“在处死gradle之前先设置道具”？我已经测试过了，显然这也是有效的。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|154490|myVar=myVal+gradle+test|code-block|syntax|javascript|154491|例如，您可以将活动配置文件设置为：|154492|SPRING_PROFILES_ACTIVE=dev++gradle+test|154493|显然，这些也是有效的：(已测试)|154494|set+myVar=myVal+&&+gradle+test++++++#+for+windows
export+myVar=myVal+&&+gradle+test+++#+for+linux+and+mac|154495|154496|entityMap^0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|R|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|S|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|T|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|U|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|V|8|@]|9|@]|A|$]]|$1|M|3|N|5|D|7|W|8|@]|9|@]|A|$E|F]]|$1|O|3|-4|5|6|7|X|8|@]|9|@]|A|$]]|$1|P|3|-4|5|6|7|Y|8|@]|9|@]|A|$]]]|Q|$]]

Maybe I am late for the party, but has anyone tried with "set the prop before executing gradle"? I have tested and this works too, apparently.

<pre><code>myVar=myVal gradle test
</code></pre>

For example, you can set the active profile like:

<pre><code>SPRING_PROFILES_ACTIVE=dev gradle test
</code></pre>

These also work, apparently:(tested)

<pre><code>set myVar=myVal &amp;&amp; gradle test # for windows
export myVar=myVal &amp;&amp; gradle test # for linux and mac
</code></pre>

Be wary that <code>myVar</code> cannot be period-separated; or else only the part before the first period will be taken as key.

I am trying to run a command-line Java app via Gradle as part of a quick integration test. I am porting my build scripts from Maven, where this was easily done via <code>exec-maven-plugin</code>. My two big requirements are:

<ul>
<li>Being able to pass system properties to the executable Java code </li>
<li>Being able to pass command-line args to the executable Java code</li>
</ul>

Please note that I am not trying to read these properties in the build script, I'm trying to read them in the Java program that the script builds and executes.

I have found two other SO posts that address Java program execution via Gradle: <a href="https://stackoverflow.com/questions/16350757/what-is-the-gradle-equivalent-of-mavens-exec-plugin-for-running-java-apps">one with an answer that advocates using <code>apply plugin: "application"</code> in the build file and <code>gradle run</code> at the command line</a>, and <a href="https://stackoverflow.com/questions/21358466/gradle-to-execute-java-class-without-modifying-build-gradle">another with answers advocating that approach as well as using <code>task execute(type:JavaExec)</code> in the build file and <code>gradle execute</code> at the command line</a>. I have tried both approaches and have not succeeded.

I have two problems:

(1) I cannot get the Java executable to read the system properties 

Whether I do this:

build.gradle:

<pre><code>apply plugin: 'application'
mainClassName = "com.mycompany.MyMain"
</code></pre>

Command line:

<pre><code>gradle run -Dmyproperty=myvalue
</code></pre>

Or this:

build.gradle:

<pre><code>task execute (type:JavaExec) {
 main = "com.mycompany.MyMain"
 classpath = sourceSets.main.runtimeClasspath 
}
</code></pre>

Command line:

<pre><code>gradle execute -Dmyproperty=myvalue
</code></pre>

In either case, <code>myproperty</code> does not make it through. The code that begins running from <code>MyMain.main (...)</code> reads the <code>myproperty</code> system property as null/missing.

(2) I cannot pass command line arguments 

This is probably related to the first problem. In <code>exec-maven-plugin</code>, for example, command line args were themselves passed in via a system property. Is that the case with Gradle, or is there another way to pass command line arguments?

How do I get these variables through? Also, is it better to use <code>apply plugin: 'application'</code> or <code>task execute (type:JavaExec)</code>?

Problems passing system properties and parameters when running Java class via Gradle

集成测试

Java

作为快速集成测试的一部分，我正在尝试通过Gradle运行一个命令行Java应用程序。我正在从Maven移植我的构建脚本，这很容易通过exec-maven-plugin完成。我的两大要求是：能够将系统属性传递给可执行Java代码能够将命令行参数传递给可执行Java代码请注意，我并不是要在构建脚本中读取这些属性，而是要在脚...

问通过Gradle运行Java类时传递系统属性和参数时出现问题
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