如果使用Maven打包成一个完整可执行的Jar包

原文链接：https://blog.dubby.cn/detail.html?id=9083

Maven提供了这么一个plugin，Apache Maven Shade Plugin。他的作用就是用来打包一个超级Jar包（被称作uber-jar），其中包含了他依赖的其他Jar包。

使用也是非常简单：

pom.xml:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>cn.dubby</groupId>
    <artifactId>undertow-demo</artifactId>
    <version>1.0</version>
    <packaging>jar</packaging>

    <properties>
        <java.version>1.8</java.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <undertow.version>1.4.21.Final</undertow.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>io.undertow</groupId>
            <artifactId>undertow-core</artifactId>
            <version>${undertow.version}</version>
        </dependency>
        <dependency>
            <groupId>io.undertow</groupId>
            <artifactId>undertow-servlet</artifactId>
            <version>${undertow.version}</version>
        </dependency>
        <dependency>
            <groupId>io.undertow</groupId>
            <artifactId>undertow-websockets-jsr</artifactId>
            <version>${undertow.version}</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                </configuration>
            </plugin>

            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-shade-plugin</artifactId>
                <version>3.1.0</version>
                <executions>
                    <execution>
                        <phase>package</phase>
                        <goals>
                            <goal>shade</goal>
                        </goals>
                        <configuration>
                            <transformers>
                                <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                                    <mainClass>cn.dubby.undertow.demo.HelloWorldServer</mainClass>
                                </transformer>
                            </transformers>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

</project>

关键的就是：

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-shade-plugin</artifactId>
    <version>3.1.0</version>
    <executions>
        <execution>
            <phase>package</phase>
            <goals>
                <goal>shade</goal>
            </goals>
            <configuration>
                <transformers>
                    <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                        <mainClass>cn.dubby.undertow.demo.HelloWorldServer</mainClass>
                    </transformer>
                </transformers>
            </configuration>
        </execution>
    </executions>
</plugin>

package cn.dubby.undertow.demo;

import io.undertow.Undertow;
import io.undertow.server.HttpHandler;
import io.undertow.server.HttpServerExchange;
import io.undertow.util.Headers;

/**
 * Created by yangzheng03 on 2018/1/4.
 */
public class HelloWorldServer {

    public static void main(final String[] args) {
        Undertow server = Undertow.builder()
                .addHttpListener(8080, "localhost")
                .setHandler(new HttpHandler() {
                    @Override
                    public void handleRequest(final HttpServerExchange exchange) throws Exception {
                        exchange.getResponseHeaders().put(Headers.CONTENT_TYPE, "text/plain");
                        exchange.getResponseSender().send("Hello World");
                    }
                }).build();
        server.start();
    }
}

因为这个plugin的goal绑定在package阶段，所以直接执行mvn package，然后cd进target目录，执行：

➜  target java -jar undertow-demo-1.0.jar         
一月 04, 2018 1:40:18 下午 org.xnio.Xnio <clinit>
INFO: XNIO version 3.3.8.Final
一月 04, 2018 1:40:18 下午 org.xnio.nio.NioXnio <clinit>
INFO: XNIO NIO Implementation Version 3.3.8.Final

就可以直接执行了~