eagerly load NestedExceptionUtils to avoid potential getMessage deadlock on OSGi (SPR-5607)

git-svn-id: https://src.springframework.org/svn/spring-framework/trunk@1149 50f2f4bb-b051-0410-bef5-90022cba6387

org.springframework.core/src/main/java/org/springframework/core/NestedCheckedException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2007 the original author or authors.
+ * Copyright 2002-2009 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -39,6 +39,12 @@ public abstract class NestedCheckedException extends Exception {
 	/** Use serialVersionUID from Spring 1.2 for interoperability */
 	private static final long serialVersionUID = 7100714597678207546L;
 
+	static {
+		// Eagerly load the NestedExceptionUtils class to avoid classloader deadlock
+		// issues on OSGi when calling getMessage(). Reported by Don Brown; SPR-5607.
+		NestedExceptionUtils.class.getName();
+	}
+
 
 	/**
 	 * Construct a <code>NestedCheckedException</code> with the specified detail message.

org.springframework.core/src/main/java/org/springframework/core/NestedIOException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2007 the original author or authors.
+ * Copyright 2002-2009 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -19,12 +19,14 @@ package org.springframework.core;
 import java.io.IOException;
 
 /**
- * Subclass of IOException that properly handles a root cause,
+ * Subclass of {@link IOException} that properly handles a root cause,
  * exposing the root cause just like NestedChecked/RuntimeException does.
  *
+ * <p>Proper root cause handling has not been added to standard IOException before
+ * Java 6, which is why we need to do it ourselves for Java 5 compatibility purposes.
+ *
  * <p>The similarity between this class and the NestedChecked/RuntimeException
- * class is unavoidable, as this class needs to derive from IOException
- * and cannot derive from NestedCheckedException.
+ * class is unavoidable, as this class needs to derive from IOException.
  *
  * @author Juergen Hoeller
  * @since 2.0
@@ -35,6 +37,13 @@ import java.io.IOException;
  */
 public class NestedIOException extends IOException {
 
+	static {
+		// Eagerly load the NestedExceptionUtils class to avoid classloader deadlock
+		// issues on OSGi when calling getMessage(). Reported by Don Brown; SPR-5607.
+		NestedExceptionUtils.class.getName();
+	}
+
+
 	/**
 	 * Construct a <code>NestedIOException</code> with the specified detail message.
 	 * @param msg the detail message

org.springframework.core/src/main/java/org/springframework/core/NestedRuntimeException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2007 the original author or authors.
+ * Copyright 2002-2009 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -39,6 +39,12 @@ public abstract class NestedRuntimeException extends RuntimeException {
 	/** Use serialVersionUID from Spring 1.2 for interoperability */
 	private static final long serialVersionUID = 5439915454935047936L;
 
+	static {
+		// Eagerly load the NestedExceptionUtils class to avoid classloader deadlock
+		// issues on OSGi when calling getMessage(). Reported by Don Brown; SPR-5607.
+		NestedExceptionUtils.class.getName();
+	}
+
 
 	/**
 	 * Construct a <code>NestedRuntimeException</code> with the specified detail message.

org.springframework.web/src/main/java/org/springframework/web/util/NestedServletException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2007 the original author or authors.
+ * Copyright 2002-2009 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,14 +21,17 @@ import javax.servlet.ServletException;
 import org.springframework.core.NestedExceptionUtils;
 
 /**
- * Subclass of ServletException that properly handles a root cause in terms
+ * Subclass of {@link ServletException} that properly handles a root cause in terms
  * of message and stacktrace, just like NestedChecked/RuntimeException does.
- * Note that the plain ServletException doesn't expose its root cause at all,
- * neither in the exception message nor in printed stack traces!
+ *
+ * <p>Note that the plain ServletException doesn't expose its root cause at all,
+ * neither in the exception message nor in printed stack traces! While this might
+ * be fixed in later Servlet API variants (which even differ per vendor for the
+ * same API version), it is not reliably available on Servlet 2.4 (the minimum
+ * version required by Spring 3.x), which is why we need to do it ourselves.
  *
  * <p>The similarity between this class and the NestedChecked/RuntimeException
- * class is unavoidable, as this class needs to derive from ServletException
- * and cannot derive from NestedCheckedException.
+ * class is unavoidable, as this class needs to derive from ServletException.
  *
  * @author Juergen Hoeller
  * @since 1.2.5
@@ -42,6 +45,12 @@ public class NestedServletException extends ServletException {
 	/** Use serialVersionUID from Spring 1.2 for interoperability */
 	private static final long serialVersionUID = -5292377985529381145L;
 
+	static {
+		// Eagerly load the NestedExceptionUtils class to avoid classloader deadlock
+		// issues on OSGi when calling getMessage(). Reported by Don Brown; SPR-5607.
+		NestedExceptionUtils.class.getName();
+	}
+
 
 	/**
 	 * Construct a <code>NestedServletException</code> with the specified detail message.