import java.io.*;
class avlnode
{
public int data,bf;
public avlnode lchild,rchild,parent;
}
class avl
{
avlnode root=null;
avlnode p=null;
avlnode prev=null;
public void insert(int ele)
{
avlnode temp=new avlnode();
temp.data=ele;
temp.lchild=null;
temp.rchild=null;
temp.parent=null;
p=new avlnode();
prev=new avlnode();
p=root;
if(root==null)
{
root=temp;
}
else
{
while(p!=null)
{
prev=p;
if(p.data>temp.data)
{
p=p.lchild;
}
else
{
p=p.rchild;
}
}
if(prev.data>temp.data)
{
prev.lchild=temp;
prev.lchild.parent=prev;
prev.bf+=1;
}
else
{
prev.rchild=temp;
prev.rchild.parent=prev;
prev.bf-=1;
}
// calculating balance factor..
while((prev!=null) && (prev.bf!=2) && (prev.bf!=-2))
{
p=prev;
prev=prev.parent;
if(prev!=null)
{
if(p==prev.lchild)
prev.bf+=1;
else
prev.bf-=1;
}
}
System.out.println("The tree before rotation");
dispre(root);
if((prev!=null) && (prev.bf==2))
{
switch(p.bf)
{
case 1:
System.out.println("left-left rotation");
ll_rotate();
dispre(root);
break;
case -1:
System.out.println("left-right rotation");
lr_rotate();
dispre(root);
break;
}
}
if((prev!=null) && (prev.bf==-2))
{
switch(p.bf)
{
case 1:
System.out.println("right-left rotation");
rl_rotate();
dispre(root);
break;
case -1:
System.out.println("right-right rotaion");
rr_rotate();
dispre(root);
break;
}
}
}
}
public void ll_rotate()
{
p.parent=prev.parent;
if(prev.parent!=null)
{
prev.parent.lchild=p;
}
p.rchild=prev;
prev.lchild=null;
if(prev==root)
root=p;
prev.bf=0;
p.bf=0;
}
public void rr_rotate()
{
p.parent=prev.parent;
if(prev.parent!=null)
{
prev.parent.rchild=p;
}
p.lchild=prev;
prev.rchild=null;
if(prev==root)
root=p;
prev.bf=0;
p.bf=0;
}
public void lr_rotate()
{
avlnode t=p.rchild;
if(t.lchild!=null)
p.rchild=t.lchild;
else
p.rchild=null;
if(t.rchild!=null)
prev.lchild=t.rchild;
else
prev.lchild=null;
if(prev.parent!=null)
{
t.parent=prev.parent;
prev.parent.lchild=t;
}

else
{
t.parent=null;
root=t;
}
t.rchild=prev;
t.lchild=p;
t.bf=0;
p.bf=0;
prev.bf=0;
}
public void rl_rotate()
{
avlnode t=p.lchild;
if(t.rchild!=null)
p.lchild=t.rchild;
else
p.lchild=null;

if(t.lchild!=null)
prev.rchild=t.lchild;
else
prev.rchild=null;
if(prev.parent!=null)
{
t.parent=prev.parent;
prev.parent.rchild=t;
}
else
{
t.parent=null;
root=t;
}
t.lchild=prev;
t.rchild=p;
t.bf=0;
p.bf=0;
prev.bf=0;

}
public void dispre(avlnode currentnode)
{
if(currentnode!=null)
{
dispre(currentnode.lchild);
System.out.println(currentnode.data+" bf:"+currentnode.bf);
dispre(currentnode.rchild);
}
}
}
class avlmain
{
public static void main(String[] args)throws IOException
{
System.out.println("AVL Tree");
DataInputStream in=new DataInputStream(System.in);
System.out.println("Enter your choice");

avl tree=new avl();
int ans;
do
{
System.out.println("Enter a data");
int val=Integer.parseInt(in.readLine());
tree.insert(val);
System.out.println("Press 1 to insert");
ans=Integer.parseInt(in.readLine());
}while(ans==1);
}
}

So what is the error you are getting .The title seems like compiler is throwing warnings.

Post your error messages here..

Look at those compiler warnings. The compiler will also suggest to you an argumnet to use during compilation. Do so, and it will tell you exactly what needs to be changed.

Look at those compiler warnings. The compiler will also suggest to you an argumnet to use during compilation. Do so, and it will tell you exactly what needs to be changed.

This ^^. Most likely you will have to use the xlint switch and specify deprecated.

Note: avlnode.java uses or overrides a deprecated API.
Note: Recompile with -Xlint:deprecation for details.

"Recompile with -Xlint:deprecation for details"

You have been told this repeatedly. Why not do it?