http://xml.apache.org/commons/components/external/: xml-commons provides an Apache-hosted set of DOM, SAX, and JAXP interfaces for use in other xml-based projects. Our hope is that we can standardize on both a common version and packaging scheme for these critical XML standards interfaces to make the lives of both our developers and users easier. The External Components portion of xml-commons contains interfaces that are defined by external standards organizations. For DOM, that's the W3C; for SAX it's David Megginson and sax.sourceforge.net; for JAXP it's Sun. 
public class javax.xml.xpath.XPathException extends java.lang.Exception
  minor version: 0
  major version: 59
  flags: flags: (0x0021) ACC_PUBLIC, ACC_SUPER
  this_class: javax.xml.xpath.XPathException
  super_class: java.lang.Exception
{
  private final java.lang.Throwable cause;
    descriptor: Ljava/lang/Throwable;
    flags: (0x0012) ACC_PRIVATE, ACC_FINAL

  private static final long serialVersionUID;
    descriptor: J
    flags: (0x001a) ACC_PRIVATE, ACC_STATIC, ACC_FINAL
    ConstantValue: -1837080260374986980

  public void <init>(java.lang.String);
    descriptor: (Ljava/lang/String;)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=3, locals=2, args_size=2
        start local 0 // javax.xml.xpath.XPathException this
        start local 1 // java.lang.String message
         0: .line 50
            aload 0 /* this */
            aload 1 /* message */
            invokespecial java.lang.Exception.<init>:(Ljava/lang/String;)V
         1: .line 51
            aload 1 /* message */
            ifnonnull 3
         2: .line 52
            new java.lang.NullPointerException
            dup
            ldc "message can't be null"
            invokespecial java.lang.NullPointerException.<init>:(Ljava/lang/String;)V
            athrow
         3: .line 54
      StackMap locals: javax.xml.xpath.XPathException java.lang.String
      StackMap stack:
            aload 0 /* this */
            aconst_null
            putfield javax.xml.xpath.XPathException.cause:Ljava/lang/Throwable;
         4: .line 55
            return
        end local 1 // java.lang.String message
        end local 0 // javax.xml.xpath.XPathException this
      LocalVariableTable:
        Start  End  Slot     Name  Signature
            0    5     0     this  Ljavax/xml/xpath/XPathException;
            0    5     1  message  Ljava/lang/String;
    MethodParameters:
         Name  Flags
      message  

  public void <init>(java.lang.Throwable);
    descriptor: (Ljava/lang/Throwable;)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=3, locals=2, args_size=2
        start local 0 // javax.xml.xpath.XPathException this
        start local 1 // java.lang.Throwable cause
         0: .line 67
            aload 0 /* this */
            aload 1 /* cause */
            ifnonnull 1
            aconst_null
            goto 2
      StackMap locals:
      StackMap stack: uninitialized-this
         1: aload 1 /* cause */
            invokevirtual java.lang.Throwable.toString:()Ljava/lang/String;
      StackMap locals: uninitialized-this java.lang.Throwable
      StackMap stack: uninitialized-this java.lang.String
         2: invokespecial java.lang.Exception.<init>:(Ljava/lang/String;)V
         3: .line 68
            aload 0 /* this */
            aload 1 /* cause */
            putfield javax.xml.xpath.XPathException.cause:Ljava/lang/Throwable;
         4: .line 69
            aload 1 /* cause */
            ifnonnull 6
         5: .line 70
            new java.lang.NullPointerException
            dup
            ldc "cause can't be null"
            invokespecial java.lang.NullPointerException.<init>:(Ljava/lang/String;)V
            athrow
         6: .line 72
      StackMap locals: javax.xml.xpath.XPathException java.lang.Throwable
      StackMap stack:
            return
        end local 1 // java.lang.Throwable cause
        end local 0 // javax.xml.xpath.XPathException this
      LocalVariableTable:
        Start  End  Slot   Name  Signature
            0    7     0   this  Ljavax/xml/xpath/XPathException;
            0    7     1  cause  Ljava/lang/Throwable;
    MethodParameters:
       Name  Flags
      cause  

  public java.lang.Throwable getCause();
    descriptor: ()Ljava/lang/Throwable;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // javax.xml.xpath.XPathException this
         0: .line 75
            aload 0 /* this */
            getfield javax.xml.xpath.XPathException.cause:Ljava/lang/Throwable;
            areturn
        end local 0 // javax.xml.xpath.XPathException this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Ljavax/xml/xpath/XPathException;

  public void printStackTrace(java.io.PrintStream);
    descriptor: (Ljava/io/PrintStream;)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // javax.xml.xpath.XPathException this
        start local 1 // java.io.PrintStream s
         0: .line 79
            aload 0 /* this */
            invokevirtual javax.xml.xpath.XPathException.getCause:()Ljava/lang/Throwable;
            ifnull 3
         1: .line 80
            aload 0 /* this */
            invokevirtual javax.xml.xpath.XPathException.getCause:()Ljava/lang/Throwable;
            aload 1 /* s */
            invokevirtual java.lang.Throwable.printStackTrace:(Ljava/io/PrintStream;)V
         2: .line 81
            aload 1 /* s */
            ldc "--------------- linked to ------------------"
            invokevirtual java.io.PrintStream.println:(Ljava/lang/String;)V
         3: .line 84
      StackMap locals:
      StackMap stack:
            aload 0 /* this */
            aload 1 /* s */
            invokespecial java.lang.Exception.printStackTrace:(Ljava/io/PrintStream;)V
         4: .line 85
            return
        end local 1 // java.io.PrintStream s
        end local 0 // javax.xml.xpath.XPathException this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    5     0  this  Ljavax/xml/xpath/XPathException;
            0    5     1     s  Ljava/io/PrintStream;
    MethodParameters:
      Name  Flags
      s     

  public void printStackTrace();
    descriptor: ()V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=1, args_size=1
        start local 0 // javax.xml.xpath.XPathException this
         0: .line 88
            aload 0 /* this */
            getstatic java.lang.System.err:Ljava/io/PrintStream;
            invokevirtual javax.xml.xpath.XPathException.printStackTrace:(Ljava/io/PrintStream;)V
         1: .line 89
            return
        end local 0 // javax.xml.xpath.XPathException this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    2     0  this  Ljavax/xml/xpath/XPathException;

  public void printStackTrace(java.io.PrintWriter);
    descriptor: (Ljava/io/PrintWriter;)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // javax.xml.xpath.XPathException this
        start local 1 // java.io.PrintWriter s
         0: .line 92
            aload 0 /* this */
            invokevirtual javax.xml.xpath.XPathException.getCause:()Ljava/lang/Throwable;
            ifnull 3
         1: .line 93
            aload 0 /* this */
            invokevirtual javax.xml.xpath.XPathException.getCause:()Ljava/lang/Throwable;
            aload 1 /* s */
            invokevirtual java.lang.Throwable.printStackTrace:(Ljava/io/PrintWriter;)V
         2: .line 94
            aload 1 /* s */
            ldc "--------------- linked to ------------------"
            invokevirtual java.io.PrintWriter.println:(Ljava/lang/String;)V
         3: .line 97
      StackMap locals:
      StackMap stack:
            aload 0 /* this */
            aload 1 /* s */
            invokespecial java.lang.Exception.printStackTrace:(Ljava/io/PrintWriter;)V
         4: .line 98
            return
        end local 1 // java.io.PrintWriter s
        end local 0 // javax.xml.xpath.XPathException this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    5     0  this  Ljavax/xml/xpath/XPathException;
            0    5     1     s  Ljava/io/PrintWriter;
    MethodParameters:
      Name  Flags
      s     
}
SourceFile: "XPathException.java"