如何使jvm加载我的java.lang.String而不是rt.jar中的那个

Question

我经常研究java类加载器.现在我想编写一个与rt.jar中的类相同的包名和类名的类.例如,自己编写一个java.lang.String类,以及如何打破父代委托模型以使jvm加载我的java.lang.String而不是rt.jar中的那个.

尝试重新编辑Thx.↓↓↓

    D:\>java -verbose -Xbootclasspath/p:D:/myrt.jar -jar exe.jar
    [Opened D:\myrt.jar]
    [Opened C:\java\jre\lib\rt.jar]
    [Loaded java.lang.Object from C:\java\jre\lib\rt.jar]
    [Loaded java.lang.String from D:\myrt.jar]
    [Loaded java.io.Serializable from C:\java\jre\lib\rt.jar]
    [Loaded java.lang.reflect.GenericDeclaration from C:\java\jre\lib\rt.jar]
    [Loaded java.lang.reflect.Type from C:\java\jre\lib\rt.jar]
    [Loaded java.lang.reflect.AnnotatedElement from C:\java\jre\lib\rt.jar]
    [Loaded java.lang.Class from C:\java\jre\lib\rt.jar]
    Invalid layout of java.lang.String at value
    #
    # A fatal error has been detected by the Java Runtime Environment:
    #
    #  Internal Error (javaClasses.cpp:136), pid=6968, tid=4116
    #  fatal error: Invalid layout of preloaded class
    #
    # JRE version:  (7.0_45-b18) (build )
    # Java VM: Java HotSpot(TM) 64-Bit Server VM (24.45-b08 mixed mode windows-amd64
     compressed oops)
    # Failed to write core dump. Minidumps are not enabled by default on client vers
    ions of Windows
    #
    # An error report file with more information is saved as:
    # D:\\hs_err_pid6968.log
    #
    # If you would like to submit a bug report, please visit:

Answer 1

您可以使用-Xbootclasspath/pJVM启动时的选项执行此操作:

-Xbootclasspath/p:/path/to/yourimpl.jar

/p 代表"前置".

注意:-Xbootclasspath不是标准的java选项,因此不同供应商的JVM可能不支持它.