I wish to exclude some class files from my jar. I am using maven-assembly-plugin. It still adds the files. I dont get any error

The maven-assembly-plugin doesn't work like that.

There what you want to do is override the configuration of the assembly descriptor jar-with-dependencies and that's not possible.

If what you want to do is create a jar similar to the one created by the assembly jar-with-dependencies but without some specific classes of your own project, you have to write your own assembly and call it in the maven-assembly-plugin like what follows.

Assembly in src/assembly/jar-with-deps-with-exclude.xml :

<assembly
    xmlns="http://maven.apache.org/plugins/maven-assembly-plugin/assembly/1.1.3"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/plugins/maven-assembly-plugin/assembly/1.1.3 http://maven.apache.org/xsd/assembly-1.1.3.xsd">
    <!-- TODO: a jarjar format would be better -->
    <id>jar-with-dependencies-and-exclude-classes</id>
    <formats>
        <format>jar</format>
    </formats>
    <includeBaseDirectory>false</includeBaseDirectory>
    <dependencySets>
        <dependencySet>
            <outputDirectory>/</outputDirectory>
            <useProjectArtifact>false</useProjectArtifact>
            <unpack>true</unpack>
            <scope>runtime</scope>
        </dependencySet>
    </dependencySets>
    <fileSets>
        <fileSet>
            <outputDirectory>/</outputDirectory>
            <directory>${project.build.outputDirectory}</directory>
            <excludes>
                <exclude>com/uiservices/controllers/*.*</exclude>
            </excludes>
        </fileSet>
    </fileSets>
</assembly>

This will create an assembly with no the dependencies unpacked and with your classes added except the ones excluded.

And then in your pom.xml :

<plugin>
    <artifactId>maven-assembly-plugin</artifactId>
    <executions>
        <execution>
            <id>only</id>
            <phase>package</phase>
            <goals>
                <goal>single</goal>
            </goals>
            <configuration>
                <descriptors>
                    <descriptor>src/assembly/jar-with-deps-with-exclude.xml</descriptor> 
                </descriptors>
            </configuration>
        </execution>
    </executions>
</plugin>

---

But if what you need is your classical jar without excluded classes, you can exclude them in the maven-jar-plugin directly :

<plugin>
    <artifactId>maven-jar-plugin</artifactId>
    <configuration>
        <excludes>
            <exclude>com/uiservices/controllers/*.*</exclude>
        </excludes>
    </configuration>
</plugin>