工具下載下傳連結：
http://iso.mirrors.ustc.edu.cn/eclipse/mat/1.7/rcp/MemoryAnalyzer-1.7.0.20170613-win32.win32.x86_64.zip
示例代碼：
import java.util.Map;
import java.util.HashMap;
public class JVMOutOfMemoryErrorSimulator {
private final static int NB_ITERATIONS = 500000;
// ~1 KB data footprint
private final static String LEAKING_DATA_PREFIX = "datadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadatadata";
// Map used to stored our leaking String instances
private static Map<String, String> leakingMap;
static {
leakingMap = new HashMap<String, String>();
}
public static void main(String[] args) {
System.out.println("JVM OutOfMemoryError Simulator 1.0");
System.out.println("Author: Pierre-Hugues Charbonneau");
System.out.println("http://javaeesupportpatterns.blogspot.com/");
try {
for (int i = 0; i < NB_ITERATIONS; i++) {
String data = LEAKING_DATA_PREFIX + i;
// Add data to our leaking Map data structure...
leakingMap.put(data, data);
}
} catch (Throwable any) {
if (any instanceof java.lang.OutOfMemoryError) {
System.out.println("OutOfMemoryError triggered! "
+ any.getMessage() + " [" + any + "]");
} else {
System.out.println("Unexpected Exception! " + any.getMessage()
+ " [" + any + "]");
}
}
System.out.println("simulator done!");
}
}
------------
程式輸出：
JVM OutOfMemoryError Simulator 1.0
Author: Pierre-Hugues Charbonneau
http://javaeesupportpatterns.blogspot.com/
java.lang.OutOfMemoryError: Java heap space
Dumping heap to java_pid15000.hprof ...
Heap dump file created [129086814 bytes in 0.464 secs]
Exception in thread "main"
Exception: java.lang.OutOfMemoryError thrown from the UncaughtExceptionHandler in thread "main"
dump檔案産生在工程目錄下：
D:\guolong\eclipsework\testWorkspace\TestProjectjava_pid15000.hprof
step1
導入上述dump檔案
step2:點，檢視可疑洩露項
step3 找到産生記憶體洩露的類，并點開詳情：
step4:定位産生洩露對象，類中變量的位置
HashMap源碼中，table屬性的位置：
HashMap源碼中，Node結構的定義：