Java Error Help and Identification

Hello there, im currently having a huge issue with my server. Im running a minecraft server with java enviroment 7, 1.5 GB, max 10 players, download speed of 24 and upload of 4.2. Im running it wired to ethernet on windows operating system. My plugins are listed below(Im aware that more plugins equals more lag). The error is also below. Whats weird about this error is that it happens at completley random times to random people. Some of my players can no longer play bceasue it almost dc's them immedtiatly. Some dc every couple of minutes or hours and some have never had it happen to them. We have good times and bad times too. This error can occur with as little as one person on. Im aware of what this basically says. That the java network has recieved something from the minecraft server the closes a previouly open port abruptly. However it is so vague and i'm not great at figuring these things. If you have any ideas on what this could be, i would really apreciate it. Also, let me know if there is anything else that you need to know, or any thing i can do.

The error:​

07:37 PM [SEVERE] java.net.SocketException: Socket closed
07:37 PM [SEVERE] at java.net.SocketOutputStream.socketWrite(Unknown Source)
07:37 PM [SEVERE] at java.net.SocketOutputStream.write(Unknown Source)
07:37 PM [SEVERE] at java.io.BufferedOutputStream.flushBuffer(Unknown Source)
07:37 PM [SEVERE] at java.io.BufferedOutputStream.flush(Unknown Source)
07:37 PM [SEVERE] at java.io.DataOutputStream.flush(Unknown Source)
07:37 PM [SEVERE] at net.minecraft.server.NetworkWriterThread.run(SourceFile:103)​

Plugins:​

- World Guard

- World Borders

- LagMeter

- AntiPub

- RegionClaim

- No lagg

- MineQuery

- Pail Plus

- ColoredSigns

- War

- Stargate

- PEX

- Multiverse-Core

- Essentails Core (except Protect)

- McGroovy

- NoLagg

- MobArena

- Found Diamonds

- Simple Spleef

- NoCheat

- VanishNoPacket

- Chestshop

- Iconomy

- Lwc


- Stargates DHD

- BKcommonLib

- InfinitePlots

- InfiniteClaims

- CraftBukkitUpToDate

- CoreProtect

- NoSpawnEggs

-PvPantilogger

-multivesre inventories​

 

You're running out of memory.

That's a ridiculous amount of plugins btw.

 

Yah i know its alot, but even when I bump it upto 6 GB ram, one player, and no lag it still happens. Are you sure that's what it is? It seems so ridiculous and also, why doesnt it give me "Cant keep up" message?