问Gradle & Java:将文件作为依赖项添加

EN

$ ls
build.gradle  dependencies  src

$ ls dependencies/
Hello.java Hello.jar

$ ls src/
Temp.java

apply plugin: 'java'

dependencies {
        compile fileTree(dir: 'dependencies', include:'**/*.jar')
}

sourceSets {
    main {
        java {
            srcDirs = ['src']
        }
    }
}

task compile(type: JavaCompile) {
    source = file('src')
}

public class Hello{
        int l = 1;
        public Hello(){
                System.out.println(l);
        }

        public static void main(String[] args){
                Hello h = new Hello();
        }
}

public class Temp {

        public static void main( String[] args0){
        Hello h = new Hello();
        }

}

   $ java -classpath build/libs/testproject.jar Temp
Exception in thread "main" java.lang.NoClassDefFoundError: Hello
        at Temp.main(Temp.java:5)
Caused by: java.lang.ClassNotFoundException: Hello
        at java.net.URLClassLoader.findClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        ... 1 more