PlayerInteractEvent - getClickedBlock().getType() - NullPointerException

My problem is that when I click the air, it produces a NullPointerException. This is the piece of my plugin that contains the problem:

Code:java

 @EventHandler
public void onWaterFillTry(PlayerInteractEvent event) {
Player p = event.getPlayer();
ItemMeta meta = p.getItemInHand().getItemMeta();
Material m = event.getClickedBlock().getType();
if (m.equals(Material.GLASS)) {
event.getPlayer().sendMessage("No puedes recoger agua con una botella de almacenamiento de experiencia.");
event.setCancelled(true);
}else{
p.sendMessage("Nada");
}
}

Code:

[16:32:48 ERROR]: Could not pass event PlayerInteractEvent to CatExp v1.1.0
org.bukkit.event.EventException
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.ja
va:294) ~[craftbukkit.jar:git-Bukkit-1.7.9-R0.2-24-g07d4558-b3116jnks]
        at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.jav
a:62) ~[craftbukkit.jar:git-Bukkit-1.7.9-R0.2-24-g07d4558-b3116jnks]
        at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.j
ava:501) [craftbukkit.jar:git-Bukkit-1.7.9-R0.2-24-g07d4558-b3116jnks]
        at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.j
ava:486) [craftbukkit.jar:git-Bukkit-1.7.9-R0.2-24-g07d4558-b3116jnks]
        at org.bukkit.craftbukkit.v1_7_R4.event.CraftEventFactory.callPlayerInte
ractEvent(CraftEventFactory.java:225) [craftbukkit.jar:git-Bukkit-1.7.9-R0.2-24-
g07d4558-b3116jnks]
        at org.bukkit.craftbukkit.v1_7_R4.event.CraftEventFactory.callPlayerInte
ractEvent(CraftEventFactory.java:195) [craftbukkit.jar:git-Bukkit-1.7.9-R0.2-24-
g07d4558-b3116jnks]
        at net.minecraft.server.v1_7_R4.PlayerConnection.a(PlayerConnection.java
:993) [craftbukkit.jar:git-Bukkit-1.7.9-R0.2-24-g07d4558-b3116jnks]
        at net.minecraft.server.v1_7_R4.PacketPlayInArmAnimation.a(SourceFile:43
) [craftbukkit.jar:git-Bukkit-1.7.9-R0.2-24-g07d4558-b3116jnks]
        at net.minecraft.server.v1_7_R4.PacketPlayInArmAnimation.handle(SourceFi
le:9) [craftbukkit.jar:git-Bukkit-1.7.9-R0.2-24-g07d4558-b3116jnks]
        at net.minecraft.server.v1_7_R4.NetworkManager.a(NetworkManager.java:157
) [craftbukkit.jar:git-Bukkit-1.7.9-R0.2-24-g07d4558-b3116jnks]
        at net.minecraft.server.v1_7_R4.ServerConnection.c(SourceFile:134) [craf
tbukkit.jar:git-Bukkit-1.7.9-R0.2-24-g07d4558-b3116jnks]
        at net.minecraft.server.v1_7_R4.MinecraftServer.v(MinecraftServer.java:6
67) [craftbukkit.jar:git-Bukkit-1.7.9-R0.2-24-g07d4558-b3116jnks]
        at net.minecraft.server.v1_7_R4.DedicatedServer.v(DedicatedServer.java:2
58) [craftbukkit.jar:git-Bukkit-1.7.9-R0.2-24-g07d4558-b3116jnks]
        at net.minecraft.server.v1_7_R4.MinecraftServer.u(MinecraftServer.java:5
58) [craftbukkit.jar:git-Bukkit-1.7.9-R0.2-24-g07d4558-b3116jnks]
        at net.minecraft.server.v1_7_R4.MinecraftServer.run(MinecraftServer.java
:469) [craftbukkit.jar:git-Bukkit-1.7.9-R0.2-24-g07d4558-b3116jnks]
        at net.minecraft.server.v1_7_R4.ThreadServerApplication.run(SourceFile:6
28) [craftbukkit.jar:git-Bukkit-1.7.9-R0.2-24-g07d4558-b3116jnks]
Caused by: java.lang.NullPointerException
        at com.github.mcat95.CatExp.CatExp.onWaterFillTry(CatExp.java:138) ~[?:?
]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.7.0
_67]
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.7.0
_67]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1
.7.0_67]
        at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.7.0_67]
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.ja
va:292) ~[craftbukkit.jar:git-Bukkit-1.7.9-R0.2-24-g07d4558-b3116jnks]
        ... 15 more

 

MetalGearDaner 1) This should be in the Plugin Development section, not Bukkit Help
2) Put in a null check (hint: in this context, air is not a block)

 

I believe you are trying to get the type of a block that does not exist(Air), and that means it's accessing invalid information. That is what's throwing the errors, I'm pretty sure.