java -cp 与 java -jar

java -cp（或java -classpath）

Designated to perform operational dependency jar and master classes require absolute path. When specifying a plurality jar, linux use of ":", windows ";" separated. You can also use the full name -classpath. Support wildcard "*." java -cp classpath, behind -cp classpath, the interpreter will find the path to a specified class file.
Format java -cp;. MyClass.jar packagename.mainclassname
e.g.
java -cp .;c:/classes/myClass.jar;d:/classes/*.jar packagename.mainclassname
java -cp D:\spark\spark-2.3.3\assembly\target\scala-2.11\jars\* org.apache.spark.deploy.master.Master
jar on the classpath may use wildcards.
packagename.mainclassname fully qualified class name mian method comprising, if there are a plurality of classes having the classpath main method by -cp inlet may conveniently selected program.
Use -jar option, java.exe will ignore -cp, -classpath and the parameters of the environment variable CLASSPATH.

java -jar

Designated to run jar, will be used MANIFEST.MF file in the META-INF generated when packaged, Main-Class which specifies the main class. You can not specify other dependent jar. ava -jar myClass.jar, when the command is executed, will use the directory META-INF \ MANIFEST.MF file in the file, there is a parameter called Main-Class, which describes the class java -jar command execution.
Java -jar myClass.jar format
e.g.
java -jar myClass.jar
java -jar E:\workspace\idmapping\target\idmapping-1.0-SNAPSHOT.jar

Specifies the main-class of two ways

When packaged Maven main-class specified in the build pom.xml
Specified in the META-INF \ MANIFEST.MF file

pom.xml of the build configuration

    <build>
        <!--<finalName>test-1.0-SNAPSHOT</finalName>-->
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.1</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                </configuration>
            </plugin>
            <plugin>
                <artifactId>maven-assembly-plugin</artifactId>
                <configuration>
                    <archive>
                        <manifest>
                        <mainClass>packagename.mainclassname</mainClass>
                        </manifest>
                    </archive>
                    <descriptorRefs>
                        <descriptorRef>jar-with-dependencies</descriptorRef>
                    </descriptorRefs>
                </configuration>
                <!--下面是为了使用 mvn package命令，如果不加则使用mvn assembly-->
                <executions>
                    <execution>
                        <id>make-assemble</id>
                        <phase>package</phase>
                        <goals>
                            <goal>single</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

META-INF \ MANIFEST.MF file specified:

Manifest-Version: 1.0
Main-Class: packagename.mainclassname

Derived using maven package, if there is no play into dependencies pom in the file, there is no dependencies.
1. Packing designated main class, can be directly used java -jar xxx.jar.
2. Packing main class is not specified, can java -cp xxx.jar main class name (absolute path).
3. To refer to other jar package, you can use java -classpath $ CLASSPATH: xxxx.jar main class name (absolute path). Wherein -classpath specified class need to be introduced.

reference