Add support of spring boot nested jar for SymDB (#7678)

Spring boot use a special jar organisation for nested ones. It uses a
new jar protocol for URL: jar:nested:

Author: jpbempel

dd-java-agent/agent-debugger/src/main/java/com/datadog/debugger/symbol/JarScanner.java

@@ -12,6 +12,7 @@
 public class JarScanner {
   private static final Logger LOGGER = LoggerFactory.getLogger(JarScanner.class);
   private static final String JAR_FILE_PREFIX = "jar:file:";
+  private static final String JAR_NESTED_PREFIX = "jar:nested:";
   private static final String FILE_PREFIX = "file:";
   // Spring prefixes:
   // https://docs.spring.io/spring-boot/docs/current/reference/html/executable-jar.html
@@ -41,6 +42,11 @@ public static Path extractJarPath(ProtectionDomain protectionDomain) throws URIS
       if (idx != -1) {
         return getPathFromPrefixedFileName(locationStr, JAR_FILE_PREFIX, idx);
       }
+    } else if (locationStr.startsWith(JAR_NESTED_PREFIX)) {
+      int idx = locationStr.indexOf("/!BOOT-INF/");
+      if (idx != -1) {
+        return getPathFromPrefixedFileName(locationStr, JAR_NESTED_PREFIX, idx);
+      }
     } else if (locationStr.startsWith(FILE_PREFIX)) {
       return getPathFromPrefixedFileName(locationStr, FILE_PREFIX, locationStr.length());
     }

dd-java-agent/agent-debugger/src/test/java/com/datadog/debugger/symbol/JarScannerTest.java

@@ -1,11 +1,16 @@
 package com.datadog.debugger.symbol;
 
 import static org.junit.jupiter.api.Assertions.*;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
 
 import java.net.MalformedURLException;
 import java.net.URISyntaxException;
 import java.net.URL;
 import java.net.URLClassLoader;
+import java.security.CodeSource;
+import java.security.ProtectionDomain;
+import java.security.cert.Certificate;
 import org.junit.jupiter.api.Test;
 
 class JarScannerTest {
@@ -31,4 +36,15 @@ public void extractJarPathFromFile() throws ClassNotFoundException, URISyntaxExc
     Class<?> testClass = urlClassLoader.loadClass(CLASS_NAME);
     assertEquals(jarFileUrl.getFile(), JarScanner.extractJarPath(testClass).toString());
   }
+
+  @Test
+  public void extractJarPathFromNestedJar() throws URISyntaxException {
+    URL jarFileUrl = getClass().getResource("/debugger-symbol.jar");
+    URL mockLocation = mock(URL.class);
+    when(mockLocation.toString())
+        .thenReturn("jar:nested:" + jarFileUrl.getFile() + "/!BOOT-INF/classes/!");
+    CodeSource codeSource = new CodeSource(mockLocation, (Certificate[]) null);
+    ProtectionDomain protectionDomain = new ProtectionDomain(codeSource, null);
+    assertEquals(jarFileUrl.getFile(), JarScanner.extractJarPath(protectionDomain).toString());
+  }
 }