解决方法：<appendAssemblyId>false</appendAssemblyId>

<build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>2.5</version>
                <configuration>
                    <source>${maven.compiler.source}</source>
                    <target>${maven.compiler.target}</target>
                    <encoding>UTF-8</encoding>
                    <compilerArguments>
                        <verbose/>
                        <bootclasspath>${java.home}/lib/rt.jar;${java.home}/lib/jce.jar</bootclasspath>
                        <extdirs>${project.basedir}/src/main/resources/lib</extdirs>
                    </compilerArguments>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-jar-plugin</artifactId>
                <configuration>
                    <classesDirectory>target/classes/</classesDirectory>
                </configuration>
            </plugin>
            
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-assembly-plugin</artifactId>
                <version>3.1.0</version>
                <configurati>
<--默认为true，则打包时会出现两个jar包，一个带 assembly id，一个不带，带assembly id的包含第三方依赖，
我们通常不需要assembly id ,所以这里设置为false -->
                <appendAssemblyId>false</appendAssemblyId>
                    <descriptors>
                        <descriptor>src/main/resources/lib/assembly.xml</descriptor>
                    </descriptors>
                    <outputDirectory>target</outputDirectory>
                </configuration>
                <executions>
                    <execution>
                        <id>make-assembly</id> <!-- this is used for inheritance merges -->
                        <phase>package</phase> <!-- 指定在打包节点执行jar包合并操作 -->
                        <goals>
                            <goal>single</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

assembly.xml

<?xml version='1.0' encoding='UTF-8'?>
<assembly xmlns="http://maven.apache.org/plugins/maven-assembly-plugin/assembly/1.1.0"
          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
          xsi:schemaLocation="http://maven.apache.org/plugins/maven-assembly-plugin/assembly/1.1.0
                    http://maven.apache.org/xsd/assembly-1.1.0.xsd">
    <id>release</id>
    <formats>
        <format>jar</format>
    </formats>
    <includeBaseDirectory>false</includeBaseDirectory>
    <fileSets>
        <fileSet>
            <directory>${project.build.directory}/classes</directory>
            <outputDirectory>./</outputDirectory>
            <excludes>
                <exclude>/lib/netty-3.7.0.Final.jar</exclude>
            </excludes>
        </fileSet>
    </fileSets>
    <dependencySets>
        <dependencySet>
            <!--<outputDirectory>/</outputDirectory>-->
            <includes>
                <!-- 把netty-3.7.0.Final打包进来，使用nls-service-sdk.jar 时需要用到，避免jar包冲突 -->
                <include>io.netty:netty</include>
            </includes>
            <useProjectArtifact>false</useProjectArtifact>
            <!-- 把打包进来的依赖解压缩  -->
            <unpack>true</unpack>
        </dependencySet>
    </dependencySets>
</assembly>