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hrmsEjb/net/sf/jasperreports/engine/util/ThreadLocalStack.java

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+package net.sf.jasperreports.engine.util;
+
+import java.util.LinkedList;
+
+public class ThreadLocalStack {
+  private final ThreadLocal threadStack = new ThreadLocal();
+  
+  public void push(Object o) {
+    LinkedList stack = this.threadStack.get();
+    if (stack == null) {
+      stack = new LinkedList();
+      this.threadStack.set(stack);
+    } 
+    stack.addFirst(o);
+  }
+  
+  public Object top() {
+    Object o = null;
+    LinkedList stack = this.threadStack.get();
+    if (stack != null && !stack.isEmpty())
+      o = stack.getFirst(); 
+    return o;
+  }
+  
+  public Object pop() {
+    Object o = null;
+    LinkedList stack = this.threadStack.get();
+    if (stack != null)
+      o = stack.removeFirst(); 
+    return o;
+  }
+  
+  public boolean empty() {
+    LinkedList stack = this.threadStack.get();
+    return (stack == null || stack.isEmpty());
+  }
+}