java - 为什么我的应用程序启动时间超过 2 分钟？

Question

我正在我的 Windows 7 64 位计算机上运行一个用 swing 制作的图形化 java 应用程序。

我的应用程序是一个可运行的 jar 文件，我使用以下命令从命令提示符启动它:

C:\path\to\jre\java.exe -jar myProg.jar

我的问题是，当我使用 JRE8 32 位时会遇到巨大的性能问题，而在使用 JRE7 32 位或 JRE8 64 位时则不会。
请注意，应用程序是使用相同的 jar 文件运行的；唯一的区别是它由不同的 JRE 运行。

我尝试了不同的 JRE8 版本，但问题仍然存在...

当我在使用“-verbose”参数时比较两个输出时，我发现我得到了超过 1500 个带有文本的输出:'[从共享对象文件加载 xxxxxx]' 对于 JRE7 而我没有得到 JRE8。< br/>也许它可能以某种方式链接？

有人知道问题出在哪里吗？

---

这是 JRE7 的一些输出

[Loaded MainFrame.MainFrame$XtrFileFilter from rsrc:./]
[Loaded java.awt.event.HierarchyListener from shared objects file]
[Loaded java.lang.InterruptedException from shared objects file]
[Loaded java.io.FileWriter from shared objects file]
[Loaded javax.swing.CellEditor from shared objects file]
[Loaded javax.swing.table.TableCellEditor from shared objects file]
[Loaded java.awt.image.RenderedImage from shared objects file]
[Loaded java.awt.image.WritableRenderedImage from shared objects file]
[Loaded java.awt.image.BufferedImage from shared objects file]
[Loaded sun.awt.util.IdentityArrayList from c:\Program Files (x86)\Java\jdk1.7.0_45\jre\lib\rt.jar]
[Loaded java.awt.Window$Type from c:\Program Files (x86)\Java\jdk1.7.0_45\jre\lib\rt.jar]
[Loaded java.util.concurrent.atomic.AtomicBoolean from shared objects file]
[Loaded sun.awt.AWTAccessor$WindowAccessor from c:\Program Files (x86)\Java\jdk1.7.0_45\jre\lib\rt.jar]
[Loaded java.awt.Window$1 from c:\Program Files (x86)\Java\jdk1.7.0_45\jre\lib\rt.jar]
[Loaded sun.awt.AWTAccessor$FrameAccessor from c:\Program Files (x86)\Java\jdk1.7.0_45\jre\lib\rt.jar]
[Loaded java.awt.Frame$1 from c:\Program Files (x86)\Java\jdk1.7.0_45\jre\lib\rt.jar]
[Loaded java.awt.ComponentOrientation from shared objects file]
[Loaded java.awt.Component$3 from c:\Program Files (x86)\Java\jdk1.7.0_45\jre\lib\rt.jar]
[Loaded javax.swing.ImageIcon from shared objects file]
[Loaded MainFrame.Simulation.Simulation from rsrc:./]
[Loaded MainFrame.Optimization.Optimization from rsrc:./]
[Loaded MainFrame.Convergence.Convergence from rsrc:./]
[Loaded java.awt.event.WindowEvent from shared objects file]
[Loaded MainFrame.Menu from rsrc:./]

这是一些 JRE8 输出

[Loaded MainFrame.MainFrame from rsrc:./]
[Loaded java.util.EventListener from c:\Program Files (x86)\Java\jre1.8.0_45\lib\rt.jar]
[Loaded java.awt.event.ActionListener from c:\Program Files (x86)\Java\jre1.8.0_45\lib\rt.jar]
[Loaded javax.swing.Action from c:\Program Files (x86)\Java\jre1.8.0_45\lib\rt.jar]
[Loaded sun.reflect.NativeMethodAccessorImpl from c:\Program Files (x86)\Java\jre1.8.0_45\lib\rt.jar]
[Loaded sun.reflect.DelegatingMethodAccessorImpl from c:\Program Files (x86)\Java\jre1.8.0_45\lib\rt.jar]
[Loaded javax.swing.UIManager from c:\Program Files (x86)\Java\jre1.8.0_45\lib\rt.jar]
[Loaded javax.swing.UIManager$LookAndFeelInfo from c:\Program Files (x86)\Java\jre1.8.0_45\lib\rt.jar]
[Loaded sun.awt.OSInfo from c:\Program Files (x86)\Java\jre1.8.0_45\lib\rt.jar]
[Loaded sun.awt.OSInfo$WindowsVersion from c:\Program Files (x86)\Java\jre1.8.0_45\lib\rt.jar]
[Loaded sun.awt.OSInfo$1 from c:\Program Files (x86)\Java\jre1.8.0_45\lib\rt.jar]
[Loaded sun.awt.OSInfo$OSType from c:\Program Files (x86)\Java\jre1.8.0_45\lib\rt.jar]
[Loaded java.awt.Toolkit from c:\Program Files (x86)\Java\jre1.8.0_45\lib\rt.jar]
[Loaded sun.awt.AWTAccessor$ToolkitAccessor from c:\Program Files (x86)\Java\jre1.8.0_45\lib\rt.jar]
[Loaded java.awt.Toolkit$4 from c:\Program Files (x86)\Java\jre1.8.0_45\lib\rt.jar]
[Loaded sun.awt.AWTAccessor from c:\Program Files (x86)\Java\jre1.8.0_45\lib\rt.jar]
[Loaded java.awt.Toolkit$5 from c:\Program Files (x86)\Java\jre1.8.0_45\lib\rt.jar]
[Loaded java.util.ResourceBundle$Control from c:\Program Files (x86)\Java\jre1.8.0_45\lib\rt.jar]
[Loaded sun.util.CoreResourceBundleControl from c:\Program Files (x86)\Java\jre1.8.0_45\lib\rt.jar]

---

我为 JRE7 和 JRE8 运行了 Xshare:dump，得到了以下结果:

JRE7:

Loading classes to share ... done.
Rewriting and unlinking classes ... done.
Calculating hash values for String objects .. done.
Calculating fingerprints ... done.
Removing unshareable information ... done.
Moving common symbols to metadata section at 0x3a033570 ... done.
Moving vmSymbols to metadata section at 0x3a1d2170 ... done.
Moving the remaining symbols to metadata section at 0x3a1d3478 ... done.
Moved 44361 symbols, 1703760 bytes.
Moving pre-ordered read-only objects to shared space at 0x38a30000 ... done.
Moving read-only objects to shared space at 0x38e129b0 ... done.
Moving string char arrays to shared space at 0x38e20cd8 ... done.
Moving pre-ordered read-write objects to shared space at 0x39430000 ... done.
Moving read-write objects to shared space at 0x399e8fb0 ... done.
Moving String objects to shared space at 0x39a3e920 ... done.
Read-write space ends at 0x39a7dd28, 6610216 bytes.
Updating references to shared objects ... done.

An error has occurred while processing the shared archive file.
Unable to create shared archive file c:\Program Files (x86)\Java\jdk1.7.0_45\jre\bin\client\classes.jsa.
Error occurred during initialization of VM
Unable to use shared archive.

JRE8:

Allocated shared space: 27394048 bytes at 0x14a00000
Loading classes to share ...
Preload Warning: Cannot find javax/swing/JComponent$2
Preload Warning: Cannot find javax/swing/RepaintManager$1$1
Preload Warning: Cannot find javax/swing/plaf/metal/MetalLookAndFeel$MetalLazyValue
Preload Warning: Cannot find javax/swing/plaf/metal/MetalLookAndFeel$MetalLazyValue$1
Preload Warning: Cannot find javax/swing/text/AbstractDocument$InsertStringResult
Preload Warning: Cannot find sun/awt/windows/WToolkit$3$1
Preload Warning: Cannot find sun/java2d/Disposer$2
Preload Warning: Cannot find sun/java2d/d3d/D3DScreenUpdateManager$1
Preload Warning: Cannot find sun/java2d/d3d/D3DScreenUpdateManager$1$1
Loading classes to share: done.
Rewriting and linking classes ...
Rewriting and linking classes: done
Number of classes 2383
    instance classes   =  2369
    obj array classes  =     6
    type array classes =     8
Calculating fingerprints ... done.
Removing unshareable information ... done.
Shared Lookup Cache Table Buckets = 4108 bytes
Shared Lookup Cache Table Body = 50352 bytes
ro space:   5650016 [ 47.7% of total] out of  12582912 bytes [44.9% used] at 0x14a00000
rw space:   5396096 [ 45.6% of total] out of  12582912 bytes [42.9% used] at 0x15600000
md space:    753892 [  6.4% of total] out of   2097152 bytes [35.9% used] at 0x16200000
mc space:     34032 [  0.3% of total] out of    131072 bytes [26.0% used] at 0x16400000
total   :  11834036 [100.0% of total] out of  27394048 bytes [43.2% used]

Answer 1

也许是 Shared Class Data您的安装存档丢失或损坏。

您可以按照 “Regenerating the Shared Archive” 下文档中的建议进行尝试

To regenerate the archive, log in as the administrator; in networked situations, log on to a machine of the same architecture as the Java SE installation and ensure that you have permission to write to the installation directory. Then execute the command

java -Xshare:dump Diagnostic information will be printed as the archive is generated.

请注意，如果失败，您可以强制使用共享数据来获取错误消息(而不是减速)，如同一页所述:

Manually Controlling Class Data Sharing

The class data sharing feature is automatically enabled when conditions allow it to be used. The following command line options are present primarily for diagnostic and debugging purposes and may change or be removed in future releases.

-Xshare:off

Disable class data sharing.

-Xshare:on

Require class data sharing to be enabled. If it could not be enabled for various reasons, print an error message and exit.

-Xshare:auto

The default; enable class data sharing whenever possible.