Error与Exception

（1）Error类和Exception类都继承自Throwable类。

Error的继承关系：
java.lang.Object-> java.lang.Throwable-> java.lang.Error

Exception的继承关系：
java.lang.Object-> java.lang.Throwable-> java.lang.Exception

（2）二者的不同之处：

 Exception：

1．可以是可被控制(checked) 或不可控制的(unchecked)

2．表示一个由程序员导致的错误

3．应该在应用程序级被处理

 Error：

1．总是不可控制的(unchecked)

2．经常用来用于表示系统错误或低层资源的错误

3．如何可能的话，应该在系统级被捕捉

（3）Java 中异常类的继承关系图：
                                

Throwable Class Hierarchy

• class java.lang.Throwable (implements java.io.Serializable)
  • class java.lang.Error
    • class java.awt.AWTError
    • class java.lang.LinkageError
      • class java.lang.ClassCircularityError
      • class java.lang.ClassFormatError
      • class java.lang.ExceptionInInitializerError
      • class java.lang.IncompatibleClassChangeError
        • class java.lang.AbstractMethodError
        • class java.lang.IllegalAccessError
        • class java.lang.InstantiationError
        • class java.lang.NoSuchFieldError
        • class java.lang.NoSuchMethodError
      • class java.lang.NoClassDefFoundError
      • class java.lang.UnsatisfiedLinkError
      • class java.lang.VerifyError
    • class java.lang.ThreadDeath
    • class java.lang.VirtualMachineError
      • class java.lang.InternalError
      • class java.lang.OutOfMemoryError
      • class java.lang.StackOverflowError
      • class java.lang.UnknownError
  • class java.lang.Exception
    • class java.awt.AWTException
    • class java.security.acl.AclNotFoundException
    • class java.rmi.AlreadyBoundException
    • class java.lang.ClassNotFoundException
    • class java.lang.CloneNotSupportedException
      • class java.rmi.server.ServerCloneException
    • class java.util.zip.DataFormatException
    • class java.security.DigestException
    • class java.io.IOException
      • class java.io.CharConversionException
      • class java.io.EOFException
      • class java.io.FileNotFoundException
      • class java.io.InterruptedIOException
      • class java.net.MalformedURLException
      • class java.io.ObjectStreamException
        • class java.io.InvalidClassException
        • class java.io.InvalidObjectException
        • class java.io.NotActiveException
        • class java.io.NotSerializableException
        • class java.io.OptionalDataException
        • class java.io.StreamCorruptedException
        • class java.io.WriteAbortedException
      • class java.net.ProtocolException
      • class java.rmi.RemoteException
        • class java.rmi.AccessException
        • class java.rmi.ConnectException
        • class java.rmi.ConnectIOException
        • class java.rmi.server.ExportException
          • class java.rmi.server.SocketSecurityException
        • class java.rmi.MarshalException
        • class java.rmi.NoSuchObjectException
        • class java.rmi.ServerError
        • class java.rmi.ServerException
        • class java.rmi.ServerRuntimeException
        • class java.rmi.server.SkeletonMismatchException
        • class java.rmi.server.SkeletonNotFoundException
        • class java.rmi.StubNotFoundException
        • class java.rmi.UnexpectedException
        • class java.rmi.UnknownHostException
        • class java.rmi.UnmarshalException
      • class java.net.SocketException
        • class java.net.BindException
        • class java.net.ConnectException
        • class java.net.NoRouteToHostException
      • class java.io.SyncFailedException
      • class java.io.UTFDataFormatException
      • class java.net.UnknownHostException
      • class java.net.UnknownServiceException
      • class java.io.UnsupportedEncodingException
      • class java.util.zip.ZipException
    • class java.lang.IllegalAccessException
    • class java.lang.InstantiationException
    • class java.lang.InterruptedException
    • class java.beans.IntrospectionException
    • class java.lang.reflect.InvocationTargetException
    • class java.security.KeyException
      • class java.security.InvalidKeyException
      • class java.security.KeyManagementException
    • class java.security.acl.LastOwnerException
    • class java.security.NoSuchAlgorithmException
    • class java.lang.NoSuchFieldException
    • class java.lang.NoSuchMethodException
    • class java.security.NoSuchProviderException
    • class java.rmi.NotBoundException
    • class java.security.acl.NotOwnerException
    • class java.text.ParseException
    • class java.beans.PropertyVetoException
    • class java.lang.RuntimeException
      • class java.lang.ArithmeticException
      • class java.lang.ArrayStoreException
      • class java.lang.ClassCastException
      • class java.util.EmptyStackException
      • class java.lang.IllegalArgumentException
        • class java.lang.IllegalThreadStateException
        • class java.security.InvalidParameterException
        • class java.lang.NumberFormatException
      • class java.lang.IllegalMonitorStateException
      • class java.lang.IllegalStateException
        • class java.awt.IllegalComponentStateException
      • class java.lang.IndexOutOfBoundsException
        • class java.lang.ArrayIndexOutOfBoundsException
        • class java.lang.StringIndexOutOfBoundsException
      • class java.util.MissingResourceException
      • class java.lang.NegativeArraySizeException
      • class java.util.NoSuchElementException
      • class java.lang.NullPointerException
      • class java.security.ProviderException
      • class java.lang.SecurityException
        • class java.rmi.RMISecurityException
    • class java.sql.SQLException
      • class java.sql.SQLWarning
        • class java.sql.DataTruncation
    • class java.rmi.server.ServerNotActiveException
    • class java.security.SignatureException
    • class java.util.TooManyListenersException
    • class java.awt.datatransfer.UnsupportedFlavorException