查看当前JRE默认堆大小（default Heap size）

 下面两个命令用于查看当前JRE默认的堆大小，该方法适用于Java 6u20以及之后版本。

 

# 使用-server
 java -server -XX:+UnlockDiagnosticVMOptions -XX:+PrintFlagsFinal -version | grep -i heapsize 
 
 

  uintx ErgoHeapSizeLimit = 0 {product} 
 
 uintx InitialHeapSize := 519327936 {product} 
 
 uintx LargePageHeapSizeThreshold = 134217728 {product} 
 
 uintx MaxHeapSize := 8311013376 {product} 
 
java version "1.6.0_27-ea" 
 
Java(TM) SE Runtime Environment (build 1.6.0_27-ea-b01) 
 
Java HotSpot(TM) 64-Bit Server VM (build 20.2-b01, mixed mode) 
 
 
 
 

  # 使用-client 
 
java -client -XX:+UnlockDiagnosticVMOptions -XX:+PrintFlagsFinal -version | grep -i heapsize 
 

  uintx ErgoHeapSizeLimit = 0 {product} 
 
 uintx InitialHeapSize := 519327936 {product} 
 
 uintx LargePageHeapSizeThreshold = 134217728 {product} 
 
 uintx MaxHeapSize := 8311013376 {product} 
 
java version "1.6.0_27-ea" 
 
Java(TM) SE Runtime Environment (build 1.6.0_27-ea-b01) 
 
Java HotSpot(TM) 64-Bit Server VM (build 20.2-b01, mixed mode)