Minor polishing and renaming

Author: Anatoly Mozgov

README.md

@@ -1,5 +1,7 @@
 # ibm-heapdump-spring-boot-actuator
-A lib to make the Spring Boot Actuator `/actuator/heapdump` endpoint work on IBM JRE
+A library that that makes the Spring Boot Actuator `/actuator/heapdump` endpoint work both on IBM J9 JVM and on HotSpot JVM. 
+
+First tries to see if the app is on J9 JVM, and falls back to Spring Boot default if it doesn't seem so. 
 
 # Usage
 
@@ -13,17 +15,17 @@ A lib to make the Spring Boot Actuator `/actuator/heapdump` endpoint work on IBM
 </dependency>
 ```
 
-2. Configure `IBMHeapdumpMvcEndpoint` bean
+2. Configure `J9HeapdumpMvcEndpoint` bean
 ```
-import com.github.sa1nt.ibmheapdump.IBMHeapdumpMvcEndpoint;
+import com.github.sa1nt.ibmheapdump.J9HeapdumpMvcEndpoint;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 
 @Configuration
-public class IbmHeapdumpConfiguration {
+public class IBMHeapdumpConfiguration {
  @Bean
- public IBMHeapdumpMvcEndpoint ibmHeapdumpMvcEndpoint() {
- return new IBMHeapdumpMvcEndpoint();
+ public J9HeapdumpMvcEndpoint ibmHeapdumpMvcEndpoint() {
+ return new J9HeapdumpMvcEndpoint();
  }
 }
 ```

pom.xml

@@ -12,7 +12,7 @@
 
  <groupId>com.github.sa1nt</groupId>
  <artifactId>ibm-heapdump-spring-boot-actuator</artifactId>
- <version>0.2</version>
+ <version>0.3</version>
 
  <dependencies>
  <dependency>

src/main/java/com/github/sa1nt/ibmheapdump/IBMHeapdumpMvcEndpoint.java

@@ -0,0 +1,47 @@
+package com.github.sa1nt.ibmheapdump;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.springframework.boot.actuate.endpoint.mvc.HeapdumpMvcEndpoint;
+import org.springframework.util.ClassUtils;
+import org.springframework.util.ReflectionUtils;
+
+import java.io.File;
+import java.lang.reflect.Method;
+import java.util.concurrent.TimeUnit;
+
+public class J9HeapdumpMvcEndpoint extends HeapdumpMvcEndpoint {
+ private static final Log logger = LogFactory.getLog(J9HeapdumpMvcEndpoint.class);
+
+ private static final String DUMP_CLASS_NAME = "com.ibm.jvm.Dump";
+ private static final String DUMP_METHOD_NAME = "heapDumpToFile";
+
+ public J9HeapdumpMvcEndpoint() {
+ super(TimeUnit.SECONDS.toMillis(10));
+ }
+
+ @Override
+ protected HeapDumper createHeapDumper() throws HeapDumperUnavailableException {
+ try {
+ Class<?> ibmDumpClass = ClassUtils.forName(DUMP_CLASS_NAME, null);
+ Method ibmDumpMethod = ReflectionUtils.findMethod(ibmDumpClass, DUMP_METHOD_NAME, String.class);
+ logger.debug("Initializing J9 HeapDumper");
+ return new J9JvmHeapDumper(ibmDumpMethod);
+ } catch (ClassNotFoundException e) {
+ logger.debug("Initializing default HeapDumper");
+ return super.createHeapDumper();
+ }
+ }
+
+ static class J9JvmHeapDumper implements HeapDumper {
+ private final Method dumpMethod;
+
+ J9JvmHeapDumper(Method dumpMethod) {
+ this.dumpMethod = dumpMethod;
+ }
+
+ public void dumpHeap(File file, boolean live) {
+ ReflectionUtils.invokeMethod(dumpMethod, null, file.getAbsolutePath());
+ }
+ }
+}