Can not connect to servers.

I am not sure this is in the right place but, one of my friends is having trouble connecting to servers so I had him force crash and this is what the report said.

Spoiler: Crash Report.

---- Minecraft Crash Report ----
// Sorry

Time: 5/21/15 6:50 PM
Description: Exception in server tick loop

java.lang.OutOfMemoryError: Java heap space
at java.util.HashMap.resize(HashMap.java:703)
at java.util.HashMap.putVal(HashMap.java:662)
at java.util.HashMap.put(HashMap.java:611)
at java.util.HashSet.add(HashSet.java:219)
at le.b(SourceFile:463)
at anj.a(SourceFile:349)
at anj.a(SourceFile:76)
at anj.a(SourceFile:63)
at ld.e(SourceFile:129)
at ld.c(SourceFile:81)
at lc$a.<init>(SourceFile:39)
at lc.a(SourceFile:231)
at lc.a(SourceFile:263)
at lx.a(SourceFile:225)
at lx.c(SourceFile:277)
at lx.a(SourceFile:132)
at lo.b(SourceFile:110)
at lo.c(SourceFile:56)
at ek.a(SourceFile:221)
at ll.c(SourceFile:168)
at net.minecraft.server.MinecraftServer.B(SourceFile:625)
at net.minecraft.server.MinecraftServer.A(SourceFile:535)
at bpo.A(SourceFile:152)
at net.minecraft.server.MinecraftServer.run(SourceFile:451)
at java.lang.Thread.run(Thread.java:745)


A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

-- System Details --
Details:
Minecraft Version: 1.8.4
Operating System: Windows 7 (amd64) version 6.1
CPU: 2x Intel(R) Core(TM)2 Duo CPU T6600 @ 2.20GHz
Java Version: 1.8.0_25, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 618040 bytes (0 MB) / 1060372480 bytes (1011 MB) up to 1060372480 bytes (1011 MB)
JVM Flags: 6 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M
IntCache: cache: 0, tcache: 0, allocated: 12, tallocated: 94
Profiler Position: N/A (disabled)
Player Count: 1 / 8; [lf['Perseus11238'/2877, l='Village and desert temple', x=-254.75, y=64.69, z=221.70]]
Type: Integrated Server (map_client.txt)
Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.

 

Thank you so much!