diff --git a/common/src/main/java/com/numeron/common/State.java b/common/src/main/java/com/numeron/common/State.java
index bd24154..cadfa88 100644
--- a/common/src/main/java/com/numeron/common/State.java
+++ b/common/src/main/java/com/numeron/common/State.java
@@ -2,6 +2,6 @@
 
 public enum State {
 
-    Non, Empty, Loading, Failure, Success
+    Empty, Loading, Failure, Success
 
 }
diff --git a/stateful-livedata/src/main/java/com/numeron/stateful/livedata/Stateful.kt b/stateful-livedata/src/main/java/com/numeron/stateful/livedata/Stateful.kt
new file mode 100644
index 0000000..655e24c
--- /dev/null
+++ b/stateful-livedata/src/main/java/com/numeron/stateful/livedata/Stateful.kt
@@ -0,0 +1,17 @@
+package com.numeron.stateful.livedata
+
+import com.numeron.common.State
+
+interface Stateful<T> {
+
+    val state: State
+
+    fun onSuccess(c: (T) -> Unit): Stateful<T>
+
+    fun onFailure(c: (String, Throwable) -> Unit): Stateful<T>
+
+    fun onLoading(c: (String, Float) -> Unit): Stateful<T>
+
+    fun onMessage(c: (String) -> Unit): Stateful<T>
+
+}
\ No newline at end of file
diff --git a/stateful-livedata/src/main/java/com/numeron/stateful/livedata/StatefulCallback.kt b/stateful-livedata/src/main/java/com/numeron/stateful/livedata/StatefulCallback.kt
new file mode 100644
index 0000000..6848b99
--- /dev/null
+++ b/stateful-livedata/src/main/java/com/numeron/stateful/livedata/StatefulCallback.kt
@@ -0,0 +1,10 @@
+package com.numeron.stateful.livedata
+
+interface StatefulCallback<T> {
+
+    fun onSuccess(value: T)
+    fun onLoading(message: String, progress: Float)
+    fun onFailure(message: String, cause: Throwable)
+    fun onMessage(message: String): Unit = Unit
+
+}
\ No newline at end of file
diff --git a/stateful-livedata/src/main/java/com/numeron/stateful/livedata/StatefulException.kt b/stateful-livedata/src/main/java/com/numeron/stateful/livedata/StatefulException.kt
new file mode 100644
index 0000000..8a7c4cf
--- /dev/null
+++ b/stateful-livedata/src/main/java/com/numeron/stateful/livedata/StatefulException.kt
@@ -0,0 +1,3 @@
+package com.numeron.stateful.livedata
+
+class StatefulException(override val message: String, cause: Throwable? = null) : RuntimeException(message, cause)
\ No newline at end of file
diff --git a/stateful-livedata/src/main/java/com/numeron/stateful/livedata/StatefulExceptionHandler.kt b/stateful-livedata/src/main/java/com/numeron/stateful/livedata/StatefulExceptionHandler.kt
new file mode 100644
index 0000000..c52ffdc
--- /dev/null
+++ b/stateful-livedata/src/main/java/com/numeron/stateful/livedata/StatefulExceptionHandler.kt
@@ -0,0 +1,35 @@
+package com.numeron.stateful.livedata
+
+import kotlinx.coroutines.CoroutineExceptionHandler
+import java.net.ConnectException
+import java.net.SocketTimeoutException
+import java.net.UnknownHostException
+import kotlin.coroutines.CoroutineContext
+
+class StatefulExceptionHandler<T>(private val statefulLiveData: StatefulLiveData<T>) : CoroutineExceptionHandler {
+
+    override val key: CoroutineContext.Key<*>
+        get() = CoroutineExceptionHandler
+
+    override fun handleException(context: CoroutineContext, exception: Throwable) {
+        exception.printStackTrace()
+        when (exception) {
+            is StatefulException -> {
+                statefulLiveData.postFailure(exception, exception.message)
+            }
+            is ConnectException, is UnknownHostException -> {
+                statefulLiveData.postFailure(exception, "无法连接到服务器，请检查网络后重试。")
+            }
+            is SocketTimeoutException -> {
+                statefulLiveData.postFailure(exception, "网络连接超时，请检查网络后重试。")
+            }
+            is NullPointerException -> {
+                statefulLiveData.postFailure(exception, "没有获取到数据，请稍候重试！")
+            }
+            else -> {
+                statefulLiveData.postFailure(exception)
+            }
+        }
+    }
+
+}
\ No newline at end of file
diff --git a/stateful-livedata/src/main/java/com/numeron/stateful/livedata/StatefulImpl.kt b/stateful-livedata/src/main/java/com/numeron/stateful/livedata/StatefulImpl.kt
new file mode 100644
index 0000000..045ba44
--- /dev/null
+++ b/stateful-livedata/src/main/java/com/numeron/stateful/livedata/StatefulImpl.kt
@@ -0,0 +1,43 @@
+package com.numeron.stateful.livedata
+
+import com.numeron.common.State
+
+internal data class StatefulImpl<T>(
+        override val state: State,
+        internal val success: T? = null,
+        internal val failure: Throwable? = null,
+        internal val progress: Float = -1f,
+        internal val message: String? = null,
+        internal val version: Int = 0,
+        internal val previous: Int = 0
+) : Stateful<T> {
+
+    override fun onSuccess(c: (T) -> Unit): Stateful<T> {
+        if (state == State.Success && success != null) {
+            c(success)
+        }
+        return this
+    }
+
+    override fun onFailure(c: (String, Throwable) -> Unit): Stateful<T> {
+        if (state == State.Failure && failure != null) {
+            c(message!!, failure)
+        }
+        return this
+    }
+
+    override fun onLoading(c: (String, Float) -> Unit): Stateful<T> {
+        if (state == State.Loading) {
+            c(message!!, progress)
+        }
+        return this
+    }
+
+    override fun onMessage(c: (String) -> Unit): Stateful<T> {
+        if (version > previous && message != null) {
+            c(message)
+        }
+        return this
+    }
+
+}
diff --git a/stateful-livedata/src/main/java/com/numeron/status/StatefulLiveData.kt b/stateful-livedata/src/main/java/com/numeron/stateful/livedata/StatefulLiveData.kt
similarity index 61%
rename from stateful-livedata/src/main/java/com/numeron/status/StatefulLiveData.kt
rename to stateful-livedata/src/main/java/com/numeron/stateful/livedata/StatefulLiveData.kt
index 6786ef0..40d61ab 100644
--- a/stateful-livedata/src/main/java/com/numeron/status/StatefulLiveData.kt
+++ b/stateful-livedata/src/main/java/com/numeron/stateful/livedata/StatefulLiveData.kt
@@ -1,21 +1,19 @@
-package com.numeron.status
+package com.numeron.stateful.livedata
 
 import androidx.lifecycle.LiveData
 import com.numeron.common.State
 
 class StatefulLiveData<T> @JvmOverloads constructor(
-        private val empty: String = "没有数据",
         private val loading: String = "正在加载",
-        private val success: String = "加载成功",
         private val failure: String = "加载失败"
 ) : LiveData<Stateful<T>>() {
 
     private val impl: StatefulImpl<T>
-        get() = super.getValue() as? StatefulImpl<T> ?: StatefulImpl(State.Non)
+        get() = getValue() as? StatefulImpl ?: StatefulImpl(State.Empty)
 
     val value: T?
         @JvmName("value")
-        get() = (super.getValue() as? StatefulImpl)?.success
+        get() = (getValue() as? StatefulImpl)?.success
 
     val requireValue: T
         @JvmName("requireValue")
@@ -30,13 +28,8 @@ class StatefulLiveData<T> @JvmOverloads constructor(
         postValue(impl.copy(state = State.Loading, progress = progress, message = message))
     }
 
-    fun postSuccess(value: T, message: String? = this.success) {
-        postValue(impl.copy(state = State.Success, success = value, message = message))
-    }
-
-    @JvmOverloads
-    fun postEmpty(empty: String = this.empty) {
-        postValue(impl.copy(state = State.Empty, message = empty))
+    fun postSuccess(value: T) {
+        postValue(impl.copy(state = State.Success, success = value))
     }
 
     fun postFailure(cause: Throwable, message: String = this.failure) {
@@ -48,7 +41,18 @@ class StatefulLiveData<T> @JvmOverloads constructor(
     }
 
     fun postMessage(message: String) {
-        postValue(impl.copy(state = State.Non, message = message))
+        postValue(impl.copy(message = message, previous = impl.version, version = impl.version + 1))
+    }
+
+    companion object {
+
+        fun <T> LiveData<T>.toStateful(loading: String = "正在加载",
+                                       failure: String = "加载失败"): StatefulLiveData<T> {
+            val statefulLiveData = StatefulLiveData<T>(loading, failure)
+            observeForever(statefulLiveData::postSuccess)
+            return statefulLiveData
+        }
+
     }
 
 }
\ No newline at end of file
diff --git a/stateful-livedata/src/main/java/com/numeron/status/StatefulObserver.kt b/stateful-livedata/src/main/java/com/numeron/stateful/livedata/StatefulObserver.kt
similarity index 73%
rename from stateful-livedata/src/main/java/com/numeron/status/StatefulObserver.kt
rename to stateful-livedata/src/main/java/com/numeron/stateful/livedata/StatefulObserver.kt
index b53f856..157771a 100644
--- a/stateful-livedata/src/main/java/com/numeron/status/StatefulObserver.kt
+++ b/stateful-livedata/src/main/java/com/numeron/stateful/livedata/StatefulObserver.kt
@@ -1,12 +1,11 @@
-package com.numeron.status
+package com.numeron.stateful.livedata
 
 import androidx.lifecycle.Observer
 
 class StatefulObserver<T>(private val callback: StatefulCallback<T>) : Observer<Stateful<T>> {
 
     override fun onChanged(stateful: Stateful<T>?) {
-        stateful?.onEmpty(callback::onEmpty)
-                ?.onFailure(callback::onFailure)
+        stateful?.onFailure(callback::onFailure)
                 ?.onMessage(callback::onMessage)
                 ?.onLoading(callback::onLoading)
                 ?.onSuccess(callback::onSuccess)
diff --git a/stateful-livedata/src/main/java/com/numeron/status/Stateful.kt b/stateful-livedata/src/main/java/com/numeron/status/Stateful.kt
deleted file mode 100644
index 940abc9..0000000
--- a/stateful-livedata/src/main/java/com/numeron/status/Stateful.kt
+++ /dev/null
@@ -1,19 +0,0 @@
-package com.numeron.status
-
-import com.numeron.common.State
-
-interface Stateful<T> {
-
-    val state: State
-
-    fun onSuccess(c: (T, String?) -> Unit): Stateful<T>
-
-    fun onFailure(c: (Throwable, String?) -> Unit): Stateful<T>
-
-    fun onLoading(c: (Float, String?) -> Unit): Stateful<T>
-
-    fun onMessage(c: (String) -> Unit): Stateful<T>
-
-    fun onEmpty(c: (String) -> Unit): Stateful<T>
-
-}
\ No newline at end of file
diff --git a/stateful-livedata/src/main/java/com/numeron/status/StatefulCallback.kt b/stateful-livedata/src/main/java/com/numeron/status/StatefulCallback.kt
deleted file mode 100644
index 923a21c..0000000
--- a/stateful-livedata/src/main/java/com/numeron/status/StatefulCallback.kt
+++ /dev/null
@@ -1,12 +0,0 @@
-package com.numeron.status
-
-
-interface StatefulCallback<T> {
-
-    fun onSuccess(value: T, message: String?)
-    fun onLoading(progress: Float, message: String?)
-    fun onFailure(cause: Throwable, message: String?)
-    fun onMessage(message: String)
-    fun onEmpty(message: String)
-
-}
\ No newline at end of file
diff --git a/stateful-livedata/src/main/java/com/numeron/status/StatefulExceptionHandler.kt b/stateful-livedata/src/main/java/com/numeron/status/StatefulExceptionHandler.kt
deleted file mode 100644
index 007ab46..0000000
--- a/stateful-livedata/src/main/java/com/numeron/status/StatefulExceptionHandler.kt
+++ /dev/null
@@ -1,16 +0,0 @@
-package com.numeron.status
-
-import kotlinx.coroutines.CoroutineExceptionHandler
-import kotlin.coroutines.CoroutineContext
-
-class StatefulExceptionHandler<T>(private val statefulLiveData: StatefulLiveData<T>) : CoroutineExceptionHandler {
-
-    override val key: CoroutineContext.Key<*>
-        get() = CoroutineExceptionHandler
-
-    override fun handleException(context: CoroutineContext, exception: Throwable) {
-        exception.printStackTrace()
-        statefulLiveData.postFailure(exception)
-    }
-
-}
\ No newline at end of file
diff --git a/stateful-livedata/src/main/java/com/numeron/status/StatefulImpl.kt b/stateful-livedata/src/main/java/com/numeron/status/StatefulImpl.kt
deleted file mode 100644
index cd4f796..0000000
--- a/stateful-livedata/src/main/java/com/numeron/status/StatefulImpl.kt
+++ /dev/null
@@ -1,48 +0,0 @@
-package com.numeron.status
-
-import com.numeron.common.State
-
-internal data class StatefulImpl<T>(
-        override val state: State,
-        internal val success: T? = null,
-        internal val failure: Throwable? = null,
-        internal val progress: Float = -1f,
-        internal val message: String? = null
-) : Stateful<T> {
-
-    override fun onSuccess(c: (T, String?) -> Unit): Stateful<T> {
-        if (state == State.Success && success != null) {
-            c(success, message)
-        }
-        return this
-    }
-
-    override fun onFailure(c: (Throwable, String?) -> Unit): Stateful<T> {
-        if (state == State.Failure && failure != null) {
-            c(failure, message)
-        }
-        return this
-    }
-
-    override fun onLoading(c: (Float, String?) -> Unit): Stateful<T> {
-        if (state == State.Loading && progress > 0f) {
-            c(progress, message)
-        }
-        return this
-    }
-
-    override fun onEmpty(c: (String) -> Unit): Stateful<T> {
-        if (state == State.Empty && message != null) {
-            c(message)
-        }
-        return this
-    }
-
-    override fun onMessage(c: (String) -> Unit): Stateful<T> {
-        if (state == State.Non && message != null) {
-            c(message)
-        }
-        return this
-    }
-
-}