我的堆转储快照低于 2 个。每次拍的时间都不一样。恐怕是我注意到对象数量的增加是正常的吗？3个对象，浅堆和reatined堆有什么区别？
快照 1
Class Name | Objects | Shallow Heap | Retained Heap
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| | |
java.lang.String | 29,635 | 948,320 | >= 2,416,080
char[] | 28,722 | 2,208,984 | >= 2,208,984
java.lang.Object | 24,001 | 384,016 | >= 384,016
java.util.HashMap$Entry | 11,077 | 354,464 | >= 6,204,552
java.util.TreeMap$Entry | 10,316 | 412,640 | >= 416,064
java.util.TreeMap | 10,143 | 486,864 | >= 902,960
java.util.Hashtable$Entry | 7,773 | 248,736 | >= 459,944
byte[] | 7,439 | 3,345,408 | >= 3,345,408
java.util.HashMap$Entry[] | 7,323 | 641,816 | >= 6,329,016
java.util.HashMap | 7,301 | 350,448 | >= 6,310,048
java.lang.ref.Finalizer | 5,208 | 208,320 | >= 2,970,240
java.util.concurrent.atomic.AtomicInteger | 5,029 | 80,464 | >= 80,488
java.io.FileDescriptor | 5,007 | 120,168 | >= 200,296
java.lang.Object[] | 4,873 | 262,048 | >= 845,856
java.net.SocksSocketImpl | 4,857 | 543,984 | >= 1,620,944
java.net.Socket | 4,856 | 155,392 | >= 233,096
java.net.SocketInputStream | 4,855 | 233,040 | >= 498,160
java.net.Inet4Address | 4,817 | 154,144 | >= 203,600
com.mysql.jdbc.ConnectionPropertiesImpl$BooleanConnectionProperty| 4,400 | 281,600 | >= 281,608
java.util.ArrayList | 3,700 | 88,800 | >= 349,928
java.util.HashSet | 3,415 | 54,640 | >= 502,096
com.mysql.jdbc.StatementImpl | 3,386 | 514,672 | >= 5,481,192
Total: 22 of 2,443 entries; 2,421 more | 250,175 | 14,989,928 |
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快照 2
Class Name | Objects | Shallow Heap | Retained Heap
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| | |
byte[] | 8,816 | 3,401,752 | >= 3,401,752
char[] | 31,516 | 1,990,752 | >= 1,990,752
java.lang.String | 32,595 | 1,043,040 | >= 2,643,008
java.net.SocksSocketImpl | 6,905 | 773,360 | >= 2,311,056
java.util.HashMap$Entry[] | 8,731 | 763,160 | >= 7,448,192
com.mysql.jdbc.JDBC4ResultSet | 4,068 | 715,968 | >= 5,326,728
com.mysql.jdbc.StatementImpl | 4,070 | 618,640 | >= 6,596,656
java.util.TreeMap | 12,202 | 585,696 | >= 1,080,624
com.mysql.jdbc.Field | 4,059 | 584,496 | >= 1,071,968
java.lang.Object | 32,988 | 527,808 | >= 527,808
java.util.TreeMap$Entry | 12,346 | 493,840 | >= 494,896
java.util.HashMap | 8,709 | 418,032 | >= 7,471,688
java.util.HashMap$Entry | 12,611 | 403,552 | >= 7,312,464
java.net.SocketInputStream | 6,903 | 331,344 | >= 710,152
java.lang.Object[] | 5,592 | 302,352 | >= 845,248
java.lang.ref.Finalizer | 7,349 | 293,960 | >= 4,300,272
com.mysql.jdbc.ConnectionPropertiesImpl$BooleanConnectionProperty| 4,400 | 281,600 | >= 281,608
java.util.Hashtable$Entry | 8,015 | 256,480 | >= 489,904
java.net.Socket | 6,904 | 220,928 | >= 331,400
java.net.Inet4Address | 6,861 | 219,552 | >= 289,680
java.io.FileDescriptor | 7,108 | 170,592 | >= 284,336
com.mysql.jdbc.RowDataStatic | 4,056 | 129,792 | >= 454,272
Total: 22 of 2,446 entries; 2,424 more | 295,977 | 16,546,032 |
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第一个快照显示 14.3 mb，第二个是 15.8mb。我从运行时获取的那个显示波动。那么哪个是正确的内存使用以及如何指示任何内存泄漏？
Runtime runtime = Runtime.getRuntime();
// Run the garbage collector
//runtime.gc();
// Calculate the used memory
long memory = runtime.totalMemory() - runtime.freeMemory();
System.out.println("\n\nUsed memory is bytes: " + memory);
//Print the jvm heap size.
long heapSize = runtime.totalMemory();
System.out.println("\n\nHeap Size = " + heapSize);
int mb = 1024*1024;
System.out.println("##### Heap utilization statistics [MB] #####");
//Print used memory
System.out.println("Used Memory:" + (runtime.totalMemory() - runtime.freeMemory()) / mb);
//Print free memory
System.out.println("Free Memory:" + runtime.freeMemory() / mb);
//Print total available memory
System.out.println("Total Memory:" + runtime.totalMemory() / mb);
//Print Maximum available memory
System.out.println("Max Memory:" + runtime.maxMemory() / mb);