feat(java): provide additional methods in java info

[SemyonSinchenko]

Describe the enhancement requested

At least we should override equals(), toString() and hashCode. It is nice to have also methods that checks is a property group in the info and methods for getting a property group by its type. These methods are important because the underlying collections are private members of info classes and the end user cannot call them.

Component(s)

Java

[Thespica]

VertexInfo and EdgeInfo can check if a PropertyGroup is in the info:

incubator-graphar/maven-projects/info/src/main/java/org/apache/graphar/info/VertexInfo.java

Lines 95 to 97 in 0bf48c1

	public boolean hasPropertyGroup(PropertyGroup propertyGroup) {
	return cachedPropertyGroups.hasPropertyGroup(propertyGroup);
	}

incubator-graphar/maven-projects/info/src/main/java/org/apache/graphar/info/EdgeInfo.java

Lines 142 to 144 in 0bf48c1

	public boolean hasPropertyGroup(PropertyGroup propertyGroup) {
	return cachedPropertyGroups.hasPropertyGroup(propertyGroup);
	}

And we can also get a PropertyGroup by type of a Propery which is in this PG in an EdgeInfo(yes, VertexInfo seems missed that method. Maybe this function should be called getBelongedPropertyGroup?):

incubator-graphar/maven-projects/info/src/main/java/org/apache/graphar/info/EdgeInfo.java

Lines 158 to 160 in 0bf48c1

	public PropertyGroup getPropertyGroup(String property) {
	return cachedPropertyGroups.getPropertyGroup(property);
	}

[SemyonSinchenko]

I was trying to map existing spark infos to the new java info and realized that some methods are missing, but it looks like they are just named differently. Thanks!

[SemyonSinchenko]

I will open a PR with equals, toString and hashCode only.

[Thespica]

I will open a PR with equals, toString and hashCode only.

Beyond this, you can add the missed method getPropertyGroup to VertexInfo. Maybe rename it to getBelongedPropertyGroup for VertexInfo and EdgeInfo will be better?