From e2b3c03fc4d2c4a8a1d0802bd2c290b4dc9d15ca Mon Sep 17 00:00:00 2001
From: Phillip Webb <pwebb@gopivotal.com>
Date: Mon, 2 Sep 2013 16:19:27 -0700
Subject: [PATCH] Refine LaunchedURLClassLoader load order

Refine the loading order of LaunchedURLClassLoader to consider the
root loader before locally bundled classes.

The prevents classes from locally bundled JARs from replacing system
classes.

Issue: #56232870
---
 .../boot/loader/LaunchedURLClassLoader.java   | 28 ++++++++++++++++++-
 1 file changed, 27 insertions(+), 1 deletion(-)

diff --git a/spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/LaunchedURLClassLoader.java b/spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/LaunchedURLClassLoader.java
index 451654a7b2..ba12d25755 100644
--- a/spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/LaunchedURLClassLoader.java
+++ b/spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/LaunchedURLClassLoader.java
@@ -31,6 +31,8 @@ import org.springframework.boot.loader.jar.RandomAccessJarFile;
  */
 public class LaunchedURLClassLoader extends URLClassLoader {
 
+	private final ClassLoader rootClassLoader;
+
 	/**
 	 * Create a new {@link LaunchedURLClassLoader} instance.
 	 * @param urls the URLs from which to load classes and resources
@@ -38,6 +40,17 @@ public class LaunchedURLClassLoader extends URLClassLoader {
 	 */
 	public LaunchedURLClassLoader(URL[] urls, ClassLoader parent) {
 		super(urls, parent);
+		this.rootClassLoader = findRootClassLoader(parent);
+	}
+
+	private ClassLoader findRootClassLoader(ClassLoader classLoader) {
+		while (classLoader != null) {
+			if (classLoader.getParent() == null) {
+				return classLoader;
+			}
+			classLoader = classLoader.getParent();
+		}
+		return null;
 	}
 
 	/**
@@ -59,11 +72,24 @@ public class LaunchedURLClassLoader extends URLClassLoader {
 	}
 
 	private Class<?> doLoadClass(String name) throws ClassNotFoundException {
+
+		// 1) Try the root class loader
+		try {
+			if (this.rootClassLoader != null) {
+				return this.rootClassLoader.loadClass(name);
+			}
+		}
+		catch (Exception ex) {
+		}
+
+		// 2) Try to find locally
 		try {
 			return findClass(name);
 		}
-		catch (ClassNotFoundException e) {
+		catch (Exception ex) {
 		}
+
+		// 3) Use standard loading
 		return super.loadClass(name, false);
 	}