com.jacob.com

Class LibraryLoader

java.lang.Object

com.jacob.com.LibraryLoader

public final class LibraryLoader
extends Object

Utility class to centralize the way in which the jacob JNI library is loaded.

This supports defining the path or library name using system properties or a custom resource file. If desired, jacob can auto-detect the correct version of the DLL for 32 or 64 bit windows, as long as you have named them differently.

1. If system property JACOB_DLL_PATH is defined, the file located there will be loaded as the jacob dll using System.load().
2. If system property JACOB_DLL_NAME is defined, the file located there will be loaded as the jacob dll.
3. If system property JACOB_DLL_NAME_X86 and JACOB_DLL_NAME_X64 are defined, the file located there will be loaded as the jacob dll, depending on the version of Windows.
4. If JACOB_DLL_NAME is defined in the com.jacob.com.JacobLibraryLoader resource file, the specified dll will be loaded from the java.library.path.
5. If JACOB_DLL_NAME_X86 and JACOB_DLL_NAME_X64 are defined in the com.jacob.com.JacobLibraryLoader resource file, the specified dll will be loaded from the java.library.path, depending on the version of Windows.
6. If none of the above are true, the default is to load the library named "jacob-<version>-<arch>" (or "jacob-<version>-<arch&rt;.dll") from the java.library.path.

The standard behavior for most applications is that LoadLibrary() will be called to load the dll. LoadLibary() searches directories specified in the variable java.library.path. This is why most test cases specify -Djava.library.path in their command line arguments.

JACOB_DLL_PATH submitted sourceforge ticket 1493647 Added 1.11
JACOB_DLL_NAME, JACOB_DLL_NAME_32, JACOB_DLL_NAME_64 submitted sourceforge ticket 1845039 Added 1.14M7

(实用程序类，用于集中加载jacob JNI库的方式。这支持使用系统属性或自定义资源文件定义路径或库名称。如果需要，jacob可以为32或64位窗口自动检测DLL的正确版本，只要您以不同的方式命名它们即可。如果定义了系统属性JACOB_DLL_PATH，则将使用System.load（）将位于此处的文件作为jacob dll加载。如果定义了系统属性JACOB_DLL_NAME，则位于该位置的文件将作为jacob dll加载。如果定义了系统属性JACOB_DLL_NAME_X86和JACOB_DLL_NAME_X64，则取决于Windows的版本，位于此处的文件将作为jacob dll加载。如果在com.jacob.com.JacobLibraryLoader资源文件中定义了JACOB_DLL_NAME，则将从java.library.path中加载指定的dll。如果在com.jacob.com.JacobLibraryLoader资源文件中定义了JACOB_DLL_NAME_X86和JACOB_DLL_NAME_X64，则取决于Windows的版本，将从java.library.path中加载指定的dll。如果以上都不是，则默认为从java.library.path加载名为“ jacob- <版本> - ”（或“ jacob- <版本> -

Author:

Scott Dickerson (sjd78), Jason Smith

Field Summary

Fields

Modifier and Type	Field and Description
static String	DLL_NAME_MODIFIER_32_BIT Appended to "jacob" when building DLL name This string must EXACTLY match the string in the build.xml file (构建DLL名称时附加到“ jacob”。此字符串必须与build.xml文件中的字符串完全匹配)
static String	DLL_NAME_MODIFIER_64_BIT Appended to "jacob" when building DLL name This string must EXACTLY match the string in the build.xml file (构建DLL名称时附加到“ jacob”。此字符串必须与build.xml文件中的字符串完全匹配)
static String	JACOB_DLL_NAME Name of system property (currently jacob.dll.name) that may contain an alternate name for the JNI library (default is 'jacob'). (系统属性的名称（当前为jacob.dll.name），其中可能包含JNI库的备用名称（默认为'jacob'）。)
static String	JACOB_DLL_NAME_X64 Name of system property (currently jacob.dll.name) that may contain an alternate name for the JNI library (default is 'jacob'), 64 bit windows. (系统属性的名称（当前为jacob.dll.name），其中可能包含JNI库的备用名称（默认为'jacob'），64位窗口。)
static String	JACOB_DLL_NAME_X86 Name of system property (currently jacob.dll.name) that may contain an alternate name for the JNI library (default is 'jacob'), 32 bit windows. (系统属性的名称（当前为jacob.dll.name），其中可能包含JNI库的备用名称（默认为'jacob'），32位窗口。)
static String	JACOB_DLL_PATH Name of system property (currently jacob.dll.path) that may contain an absolute path to the JNI library. (系统属性的名称（当前为jacob.dll.path），其中可能包含JNI库的绝对路径。)

Constructor Summary

Constructors

Constructor and Description
LibraryLoader()

Method Summary

Methods

Modifier and Type	Method and Description
static String	getPreferredDLLName() Developer note: This method MUST be synchronized with the DLL names created as part of the build process in build.xml (开发人员说明：此方法必须与在build.xml中作为生成过程的一部分创建的DLL名称同步。)
static void	loadJacobLibrary() Load the jacob dll either from an absolute path or by a library name, both of which may be defined in various ways. (从绝对路径或通过库名加载jacob dll，这两种定义都可以通过各种方式进行。)
protected static boolean	shouldLoad32Bit() Detects whether this is a 32-bit JVM. (检测这是否是32位JVM。)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

JACOB_DLL_PATH

public static final String JACOB_DLL_PATH

Name of system property (currently jacob.dll.path) that may contain an absolute path to the JNI library. (系统属性的名称（当前为jacob.dll.path），其中可能包含JNI库的绝对路径。)

See Also:

Constant Field Values

JACOB_DLL_NAME

public static final String JACOB_DLL_NAME

Name of system property (currently jacob.dll.name) that may contain an alternate name for the JNI library (default is 'jacob'). (系统属性的名称（当前为jacob.dll.name），其中可能包含JNI库的备用名称（默认为'jacob'）。)

See Also:

Constant Field Values

JACOB_DLL_NAME_X86

public static final String JACOB_DLL_NAME_X86

Name of system property (currently jacob.dll.name) that may contain an alternate name for the JNI library (default is 'jacob'), 32 bit windows. (系统属性的名称（当前为jacob.dll.name），其中可能包含JNI库的备用名称（默认为'jacob'），32位窗口。)

See Also:

Constant Field Values

JACOB_DLL_NAME_X64

public static final String JACOB_DLL_NAME_X64

Name of system property (currently jacob.dll.name) that may contain an alternate name for the JNI library (default is 'jacob'), 64 bit windows. (系统属性的名称（当前为jacob.dll.name），其中可能包含JNI库的备用名称（默认为'jacob'），64位窗口。)

See Also:

Constant Field Values

DLL_NAME_MODIFIER_32_BIT

public static final String DLL_NAME_MODIFIER_32_BIT

Appended to "jacob" when building DLL name This string must EXACTLY match the string in the build.xml file (构建DLL名称时附加到“ jacob”。此字符串必须与build.xml文件中的字符串完全匹配)

See Also:

Constant Field Values

DLL_NAME_MODIFIER_64_BIT

public static final String DLL_NAME_MODIFIER_64_BIT

Appended to "jacob" when building DLL name This string must EXACTLY match the string in the build.xml file (构建DLL名称时附加到“ jacob”。此字符串必须与build.xml文件中的字符串完全匹配)

See Also:

Constant Field Values

Constructor Detail

LibraryLoader

public LibraryLoader()

Method Detail

loadJacobLibrary

public static void loadJacobLibrary()

Load the jacob dll either from an absolute path or by a library name, both of which may be defined in various ways. (从绝对路径或通过库名加载jacob dll，这两种定义都可以通过各种方式进行。)

Throws:

UnsatisfiedLinkError - if the library does not exist.

getPreferredDLLName

public static String getPreferredDLLName()

Developer note: This method MUST be synchronized with the DLL names created as part of the build process in build.xml

The DLL name is "jacob\ .release"

(开发人员说明：此方法必须与在build.xml中作为构建过程的一部分创建的DLL名称同步。DLL名称为“ jacob \ .release”)

Returns:

the preferred name of the DLL adjusted for this platform and version without the ".dll" extension (为该平台和版本调整的DLL的首选名称，不带“ .dll”扩展名)

shouldLoad32Bit

protected static boolean shouldLoad32Bit()

Detects whether this is a 32-bit JVM. (检测这是否是32位JVM。)

Returns:

true if this is a 32-bit JVM. (如果是32位JVM。)