diff --git a/docs/convert.md b/docs/convert.md
index cc2e96abf..9f5983261 100644
--- a/docs/convert.md
+++ b/docs/convert.md
@@ -324,7 +324,9 @@ public class InnerCoderEntity {
 
             @Override
             public InnerCoderEntity convertFrom(Reader in) {
-                if (in.readObjectB(InnerCoderEntity.class) == null) return null;
+                if (!in.readObjectB(this)) {
+                    return null;
+                }
                 int index = 0;
                 final Object[] params = new Object[deMembers.length];
                 while (in.hasNext()) {
@@ -336,7 +338,7 @@ public class InnerCoderEntity {
                         params[index++] = member.read(in);
                     }
                 }
-                in.readObjectE(InnerCoderEntity.class);
+                in.readObjectE();
                 return InnerCoderEntity.create(params[0] == null ? 0 : (Integer) params[0], (String) params[1]);
             }
         };
diff --git a/src/main/java/org/redkale/convert/ArrayDecoder.java b/src/main/java/org/redkale/convert/ArrayDecoder.java
index da35fcb57..205a98ae2 100644
--- a/src/main/java/org/redkale/convert/ArrayDecoder.java
+++ b/src/main/java/org/redkale/convert/ArrayDecoder.java
@@ -90,19 +90,12 @@ public class ArrayDecoder<R extends Reader, T> implements Decodeable<R, T[]> {
     public T[] convertFrom(R in) {
         this.checkInited();
         final Decodeable<R, T> itemDecoder = this.componentDecoder;
-        int len = in.readArrayB(itemDecoder);
-        if (len == Reader.SIGN_NULL) {
+        if (!in.readArrayB(itemDecoder)) {
             return null;
         }
         final List<T> result = new ArrayList();
-        if (len == Reader.SIGN_VARIABLE) {
-            while (in.hasNext()) {
-                result.add(itemDecoder.convertFrom(in));
-            }
-        } else { // 固定长度
-            for (int i = 0; i < len; i++) {
-                result.add(itemDecoder.convertFrom(in));
-            }
+        while (in.hasNext()) {
+            result.add(itemDecoder.convertFrom(in));
         }
         in.readArrayE();
         T[] rs = this.componentArrayFunction.apply(result.size());
diff --git a/src/main/java/org/redkale/convert/CollectionDecoder.java b/src/main/java/org/redkale/convert/CollectionDecoder.java
index a4b188375..1660161f1 100644
--- a/src/main/java/org/redkale/convert/CollectionDecoder.java
+++ b/src/main/java/org/redkale/convert/CollectionDecoder.java
@@ -95,19 +95,12 @@ public class CollectionDecoder<R extends Reader, T> implements Decodeable<R, Col
     public Collection<T> convertFrom(R in) {
         this.checkInited();
         final Decodeable<R, T> itemDecoder = this.componentDecoder;
-        int size = in.readArrayB(itemDecoder);
-        if (size == Reader.SIGN_NULL) {
+        if (!in.readArrayB(itemDecoder)) {
             return null;
         }
         final Collection<T> result = this.creator.create();
-        if (size == Reader.SIGN_VARIABLE) {
-            while (in.hasNext()) {
-                result.add(itemDecoder.convertFrom(in));
-            }
-        } else { // 固定长度
-            for (int i = 0; i < size; i++) {
-                result.add(itemDecoder.convertFrom(in));
-            }
+        while (in.hasNext()) {
+            result.add(itemDecoder.convertFrom(in));
         }
         in.readArrayE();
         return result;
diff --git a/src/main/java/org/redkale/convert/MapDecoder.java b/src/main/java/org/redkale/convert/MapDecoder.java
index a163c1bbc..63ba91dd5 100644
--- a/src/main/java/org/redkale/convert/MapDecoder.java
+++ b/src/main/java/org/redkale/convert/MapDecoder.java
@@ -118,25 +118,15 @@ public class MapDecoder<R extends Reader, K, V> implements Decodeable<R, Map<K,
         this.checkInited();
         Decodeable<R, K> kdecoder = this.keyDecoder;
         Decodeable<R, V> vdecoder = this.valueDecoder;
-        int len = in.readMapB(kdecoder, vdecoder);
-        if (len == Reader.SIGN_NULL) {
+        if (!in.readMapB(kdecoder, vdecoder)) {
             return null;
         }
         final Map<K, V> result = this.creator.create();
-        if (len == Reader.SIGN_VARIABLE) {
-            while (in.hasNext()) {
-                K key = kdecoder.convertFrom(in);
-                in.readColon();
-                V value = vdecoder.convertFrom(in);
-                result.put(key, value);
-            }
-        } else { // 固定长度
-            for (int i = 0; i < len; i++) {
-                K key = kdecoder.convertFrom(in);
-                in.readColon();
-                V value = vdecoder.convertFrom(in);
-                result.put(key, value);
-            }
+        while (in.hasNext()) {
+            K key = kdecoder.convertFrom(in);
+            in.readColon();
+            V value = vdecoder.convertFrom(in);
+            result.put(key, value);
         }
         in.readMapE();
         return result;
diff --git a/src/main/java/org/redkale/convert/ObjectDecoder.java b/src/main/java/org/redkale/convert/ObjectDecoder.java
index 80096be9a..71a8ce68a 100644
--- a/src/main/java/org/redkale/convert/ObjectDecoder.java
+++ b/src/main/java/org/redkale/convert/ObjectDecoder.java
@@ -360,8 +360,7 @@ public class ObjectDecoder<R extends Reader, T> implements Decodeable<R, T> {
     @Override
     public T convertFrom(final R in) {
         this.checkInited();
-        final String clazz = in.readObjectB(typeClass);
-        if (clazz == null) {
+        if (!in.readObjectB(this)) {
             return null;
         }
         if (this.creator == null) {
@@ -384,7 +383,7 @@ public class ObjectDecoder<R extends Reader, T> implements Decodeable<R, T> {
                     member.getAttribute().set(result, val);
                 }
             }
-            in.readObjectE(typeClass);
+            in.readObjectE();
             return result;
         } else { // 带参数的构造函数
             final DeMember<R, T, ?>[] constructorFields = this.creatorConstructorMembers;
@@ -411,7 +410,7 @@ public class ObjectDecoder<R extends Reader, T> implements Decodeable<R, T> {
                     }
                 }
             }
-            in.readObjectE(typeClass);
+            in.readObjectE();
             if (this.creator == null) {
                 return null;
             }
diff --git a/src/main/java/org/redkale/convert/Reader.java b/src/main/java/org/redkale/convert/Reader.java
index 8d2da9942..f76caab3f 100644
--- a/src/main/java/org/redkale/convert/Reader.java
+++ b/src/main/java/org/redkale/convert/Reader.java
@@ -16,20 +16,6 @@ import org.redkale.annotation.Nullable;
  */
 public abstract class Reader {
 
-    /**
-     * 集合对象为null
-     *
-     * @see #readArrayB(org.redkale.convert.Decodeable)
-     */
-    public static final short SIGN_NULL = -1;
-
-    /**
-     * 不确定的长度， 比如解析json数组
-     *
-     * @see #readArrayB(org.redkale.convert.Decodeable)
-     */
-    public static final short SIGN_VARIABLE = -2;
-
     /**
      * 设置Reader的内容，通常结合对象池使用
      *
@@ -62,32 +48,26 @@ public abstract class Reader {
     public abstract void readColon();
 
     /**
-     * 读取对象的类名， 返回 null 表示对象为null， 返回空字符串表示当前class与返回的class一致，返回非空字符串表示class是当前class的子类。
+     * 读取对象，返回false表示对象为null
      *
-     * @param clazz 类名
-     *
-     * @return 返回字段数
+     * @param decoder Decodeable
+     * @return 是否存在对象
      */
-    public String readObjectB(final Class clazz) {
-        return null;
-    }
+    public abstract boolean readObjectB(final Decodeable decoder);
 
     /**
      * 读取对象的尾端
      *
-     * @param clazz 类名
      */
-    public abstract void readObjectE(final Class clazz);
+    public abstract void readObjectE();
 
     /**
-     * 读取数组的开头并返回数组的长度
+     * 读取数组，返回false表示数组为null
      *
-     * @see #SIGN_NULL
-     * @see #SIGN_VARIABLE
      * @param componentDecoder Decodeable
-     * @return 返回数组的长度
+     * @return 是否存在对象
      */
-    public abstract int readArrayB(@Nullable Decodeable componentDecoder);
+    public abstract boolean readArrayB(@Nullable Decodeable componentDecoder);
 
     /**
      * 读取数组的尾端
@@ -95,13 +75,13 @@ public abstract class Reader {
     public abstract void readArrayE();
 
     /**
-     * 读取map的开头并返回map的size
+     * 读取map，返回false表示map为null
      *
      * @param keyDecoder Decodeable
      * @param valueDecoder Decodeable
-     * @return 返回map的size
+     * @return 是否存在对象
      */
-    public abstract int readMapB(Decodeable keyDecoder, Decodeable valueDecoder);
+    public abstract boolean readMapB(Decodeable keyDecoder, Decodeable valueDecoder);
 
     /**
      * 读取Map的尾端
diff --git a/src/main/java/org/redkale/convert/StreamDecoder.java b/src/main/java/org/redkale/convert/StreamDecoder.java
index a1a61611b..1561c0b27 100644
--- a/src/main/java/org/redkale/convert/StreamDecoder.java
+++ b/src/main/java/org/redkale/convert/StreamDecoder.java
@@ -80,19 +80,12 @@ public class StreamDecoder<R extends Reader, T> implements Decodeable<R, Stream<
     public Stream<T> convertFrom(R in) {
         this.checkInited();
         final Decodeable<R, T> itemDecoder = this.componentDecoder;
-        int len = in.readArrayB(itemDecoder);
-        if (len == Reader.SIGN_NULL) {
+        if (!in.readArrayB(itemDecoder)) {
             return null;
         }
         final List<T> result = new ArrayList();
-        if (len == Reader.SIGN_VARIABLE) {
-            while (in.hasNext()) {
-                result.add(itemDecoder.convertFrom(in));
-            }
-        } else { // 固定长度
-            for (int i = 0; i < len; i++) {
-                result.add(itemDecoder.convertFrom(in));
-            }
+        while (in.hasNext()) {
+            result.add(itemDecoder.convertFrom(in));
         }
         in.readArrayE();
         return result.stream();
diff --git a/src/main/java/org/redkale/convert/ext/BoolArraySimpledCoder.java b/src/main/java/org/redkale/convert/ext/BoolArraySimpledCoder.java
index f4d14abb2..8e7761e16 100644
--- a/src/main/java/org/redkale/convert/ext/BoolArraySimpledCoder.java
+++ b/src/main/java/org/redkale/convert/ext/BoolArraySimpledCoder.java
@@ -40,32 +40,22 @@ public final class BoolArraySimpledCoder<R extends Reader, W extends Writer> ext
 
     @Override
     public boolean[] convertFrom(R in) {
-        int len = in.readArrayB(BoolSimpledCoder.instance);
-        if (len == Reader.SIGN_NULL) {
+        if (!in.readArrayB(BoolSimpledCoder.instance)) {
             return null;
         }
-        if (len == Reader.SIGN_VARIABLE) {
-            int size = 0;
-            boolean[] data = new boolean[8];
-            while (in.hasNext()) {
-                if (size >= data.length) {
-                    boolean[] newdata = new boolean[data.length + 4];
-                    System.arraycopy(data, 0, newdata, 0, size);
-                    data = newdata;
-                }
-                data[size++] = in.readBoolean();
+        int size = 0;
+        boolean[] data = new boolean[8];
+        while (in.hasNext()) {
+            if (size >= data.length) {
+                boolean[] newdata = new boolean[data.length + 4];
+                System.arraycopy(data, 0, newdata, 0, size);
+                data = newdata;
             }
-            in.readArrayE();
-            boolean[] newdata = new boolean[size];
-            System.arraycopy(data, 0, newdata, 0, size);
-            return newdata;
-        } else {
-            boolean[] values = new boolean[len];
-            for (int i = 0; i < values.length; i++) {
-                values[i] = in.readBoolean();
-            }
-            in.readArrayE();
-            return values;
+            data[size++] = in.readBoolean();
         }
+        in.readArrayE();
+        boolean[] newdata = new boolean[size];
+        System.arraycopy(data, 0, newdata, 0, size);
+        return newdata;
     }
 }
diff --git a/src/main/java/org/redkale/convert/ext/ByteBufferSimpledCoder.java b/src/main/java/org/redkale/convert/ext/ByteBufferSimpledCoder.java
index c0848d5cc..e96bb143e 100644
--- a/src/main/java/org/redkale/convert/ext/ByteBufferSimpledCoder.java
+++ b/src/main/java/org/redkale/convert/ext/ByteBufferSimpledCoder.java
@@ -41,30 +41,20 @@ public final class ByteBufferSimpledCoder<R extends Reader, W extends Writer> ex
 
     @Override
     public ByteBuffer convertFrom(R in) {
-        int len = in.readArrayB(ByteSimpledCoder.instance);
-        if (len == Reader.SIGN_NULL) {
+        if (!in.readArrayB(ByteSimpledCoder.instance)) {
             return null;
         }
-        if (len == Reader.SIGN_VARIABLE) {
-            int size = 0;
-            byte[] data = new byte[8];
-            while (in.hasNext()) {
-                if (size >= data.length) {
-                    byte[] newdata = new byte[data.length + 4];
-                    System.arraycopy(data, 0, newdata, 0, size);
-                    data = newdata;
-                }
-                data[size++] = in.readByte();
+        int size = 0;
+        byte[] data = new byte[8];
+        while (in.hasNext()) {
+            if (size >= data.length) {
+                byte[] newdata = new byte[data.length + 4];
+                System.arraycopy(data, 0, newdata, 0, size);
+                data = newdata;
             }
-            in.readArrayE();
-            return ByteBuffer.wrap(data, 0, size);
-        } else {
-            byte[] values = new byte[len];
-            for (int i = 0; i < values.length; i++) {
-                values[i] = in.readByte();
-            }
-            in.readArrayE();
-            return ByteBuffer.wrap(values);
+            data[size++] = in.readByte();
         }
+        in.readArrayE();
+        return ByteBuffer.wrap(data, 0, size);
     }
 }
diff --git a/src/main/java/org/redkale/convert/ext/CharArraySimpledCoder.java b/src/main/java/org/redkale/convert/ext/CharArraySimpledCoder.java
index d72f299cb..26b3a4eaf 100644
--- a/src/main/java/org/redkale/convert/ext/CharArraySimpledCoder.java
+++ b/src/main/java/org/redkale/convert/ext/CharArraySimpledCoder.java
@@ -40,32 +40,22 @@ public final class CharArraySimpledCoder<R extends Reader, W extends Writer> ext
 
     @Override
     public char[] convertFrom(R in) {
-        int len = in.readArrayB(CharSimpledCoder.instance);
-        if (len == Reader.SIGN_NULL) {
+        if (!in.readArrayB(CharSimpledCoder.instance)) {
             return null;
         }
-        if (len == Reader.SIGN_VARIABLE) {
-            int size = 0;
-            char[] data = new char[8];
-            while (in.hasNext()) {
-                if (size >= data.length) {
-                    char[] newdata = new char[data.length + 4];
-                    System.arraycopy(data, 0, newdata, 0, size);
-                    data = newdata;
-                }
-                data[size++] = in.readChar();
+        int size = 0;
+        char[] data = new char[8];
+        while (in.hasNext()) {
+            if (size >= data.length) {
+                char[] newdata = new char[data.length + 4];
+                System.arraycopy(data, 0, newdata, 0, size);
+                data = newdata;
             }
-            in.readArrayE();
-            char[] newdata = new char[size];
-            System.arraycopy(data, 0, newdata, 0, size);
-            return newdata;
-        } else {
-            char[] values = new char[len];
-            for (int i = 0; i < values.length; i++) {
-                values[i] = in.readChar();
-            }
-            in.readArrayE();
-            return values;
+            data[size++] = in.readChar();
         }
+        in.readArrayE();
+        char[] newdata = new char[size];
+        System.arraycopy(data, 0, newdata, 0, size);
+        return newdata;
     }
 }
diff --git a/src/main/java/org/redkale/convert/ext/CompletionHandlerSimpledCoder.java b/src/main/java/org/redkale/convert/ext/CompletionHandlerSimpledCoder.java
index b9520b53a..f784ce58a 100644
--- a/src/main/java/org/redkale/convert/ext/CompletionHandlerSimpledCoder.java
+++ b/src/main/java/org/redkale/convert/ext/CompletionHandlerSimpledCoder.java
@@ -29,7 +29,7 @@ public final class CompletionHandlerSimpledCoder<R extends Reader, W extends Wri
 
     @Override
     public CompletionHandler convertFrom(R in) {
-        in.readObjectB(CompletionHandler.class);
+        in.readObjectB(this);
         return null;
     }
 }
diff --git a/src/main/java/org/redkale/convert/ext/DoubleArraySimpledCoder.java b/src/main/java/org/redkale/convert/ext/DoubleArraySimpledCoder.java
index eb225c70c..d713354de 100644
--- a/src/main/java/org/redkale/convert/ext/DoubleArraySimpledCoder.java
+++ b/src/main/java/org/redkale/convert/ext/DoubleArraySimpledCoder.java
@@ -41,33 +41,23 @@ public final class DoubleArraySimpledCoder<R extends Reader, W extends Writer> e
 
     @Override
     public double[] convertFrom(R in) {
-        int len = in.readArrayB(DoubleSimpledCoder.instance);
-        if (len == Reader.SIGN_NULL) {
+        if (!in.readArrayB(DoubleSimpledCoder.instance)) {
             return null;
         }
-        if (len == Reader.SIGN_VARIABLE) {
-            int size = 0;
-            double[] data = new double[8];
-            while (in.hasNext()) {
-                if (size >= data.length) {
-                    double[] newdata = new double[data.length + 4];
-                    System.arraycopy(data, 0, newdata, 0, size);
-                    data = newdata;
-                }
-                data[size++] = in.readDouble();
+        int size = 0;
+        double[] data = new double[8];
+        while (in.hasNext()) {
+            if (size >= data.length) {
+                double[] newdata = new double[data.length + 4];
+                System.arraycopy(data, 0, newdata, 0, size);
+                data = newdata;
             }
-            in.readArrayE();
-            double[] newdata = new double[size];
-            System.arraycopy(data, 0, newdata, 0, size);
-            return newdata;
-        } else {
-            double[] values = new double[len];
-            for (int i = 0; i < values.length; i++) {
-                values[i] = in.readDouble();
-            }
-            in.readArrayE();
-            return values;
+            data[size++] = in.readDouble();
         }
+        in.readArrayE();
+        double[] newdata = new double[size];
+        System.arraycopy(data, 0, newdata, 0, size);
+        return newdata;
     }
 
     public static final class DoubleStreamSimpledCoder<R extends Reader, W extends Writer>
diff --git a/src/main/java/org/redkale/convert/ext/FloatArraySimpledCoder.java b/src/main/java/org/redkale/convert/ext/FloatArraySimpledCoder.java
index b5ad5fce8..8afd1d448 100644
--- a/src/main/java/org/redkale/convert/ext/FloatArraySimpledCoder.java
+++ b/src/main/java/org/redkale/convert/ext/FloatArraySimpledCoder.java
@@ -40,32 +40,22 @@ public final class FloatArraySimpledCoder<R extends Reader, W extends Writer> ex
 
     @Override
     public float[] convertFrom(R in) {
-        int len = in.readArrayB(FloatSimpledCoder.instance);
-        if (len == Reader.SIGN_NULL) {
+        if (!in.readArrayB(FloatSimpledCoder.instance)) {
             return null;
         }
-        if (len == Reader.SIGN_VARIABLE) {
-            int size = 0;
-            float[] data = new float[8];
-            while (in.hasNext()) {
-                if (size >= data.length) {
-                    float[] newdata = new float[data.length + 4];
-                    System.arraycopy(data, 0, newdata, 0, size);
-                    data = newdata;
-                }
-                data[size++] = in.readFloat();
+        int size = 0;
+        float[] data = new float[8];
+        while (in.hasNext()) {
+            if (size >= data.length) {
+                float[] newdata = new float[data.length + 4];
+                System.arraycopy(data, 0, newdata, 0, size);
+                data = newdata;
             }
-            in.readArrayE();
-            float[] newdata = new float[size];
-            System.arraycopy(data, 0, newdata, 0, size);
-            return newdata;
-        } else {
-            float[] values = new float[len];
-            for (int i = 0; i < values.length; i++) {
-                values[i] = in.readFloat();
-            }
-            in.readArrayE();
-            return values;
+            data[size++] = in.readFloat();
         }
+        in.readArrayE();
+        float[] newdata = new float[size];
+        System.arraycopy(data, 0, newdata, 0, size);
+        return newdata;
     }
 }
diff --git a/src/main/java/org/redkale/convert/ext/IntArraySimpledCoder.java b/src/main/java/org/redkale/convert/ext/IntArraySimpledCoder.java
index a2fa94358..50f573c7c 100644
--- a/src/main/java/org/redkale/convert/ext/IntArraySimpledCoder.java
+++ b/src/main/java/org/redkale/convert/ext/IntArraySimpledCoder.java
@@ -41,33 +41,23 @@ public final class IntArraySimpledCoder<R extends Reader, W extends Writer> exte
 
     @Override
     public int[] convertFrom(R in) {
-        int len = in.readArrayB(IntSimpledCoder.instance);
-        if (len == Reader.SIGN_NULL) {
+        if (!in.readArrayB(IntSimpledCoder.instance)) {
             return null;
         }
-        if (len == Reader.SIGN_VARIABLE) {
-            int size = 0;
-            int[] data = new int[8];
-            while (in.hasNext()) {
-                if (size >= data.length) {
-                    int[] newdata = new int[data.length + 4];
-                    System.arraycopy(data, 0, newdata, 0, size);
-                    data = newdata;
-                }
-                data[size++] = in.readInt();
+        int size = 0;
+        int[] data = new int[8];
+        while (in.hasNext()) {
+            if (size >= data.length) {
+                int[] newdata = new int[data.length + 4];
+                System.arraycopy(data, 0, newdata, 0, size);
+                data = newdata;
             }
-            in.readArrayE();
-            int[] newdata = new int[size];
-            System.arraycopy(data, 0, newdata, 0, size);
-            return newdata;
-        } else {
-            int[] values = new int[len];
-            for (int i = 0; i < values.length; i++) {
-                values[i] = in.readInt();
-            }
-            in.readArrayE();
-            return values;
+            data[size++] = in.readInt();
         }
+        in.readArrayE();
+        int[] newdata = new int[size];
+        System.arraycopy(data, 0, newdata, 0, size);
+        return newdata;
     }
 
     public static final class IntStreamSimpledCoder<R extends Reader, W extends Writer>
diff --git a/src/main/java/org/redkale/convert/ext/LongArraySimpledCoder.java b/src/main/java/org/redkale/convert/ext/LongArraySimpledCoder.java
index 586408fd7..f3e1fd697 100644
--- a/src/main/java/org/redkale/convert/ext/LongArraySimpledCoder.java
+++ b/src/main/java/org/redkale/convert/ext/LongArraySimpledCoder.java
@@ -41,33 +41,23 @@ public final class LongArraySimpledCoder<R extends Reader, W extends Writer> ext
 
     @Override
     public long[] convertFrom(R in) {
-        int len = in.readArrayB(LongSimpledCoder.instance);
-        if (len == Reader.SIGN_NULL) {
+        if (!in.readArrayB(LongSimpledCoder.instance)) {
             return null;
         }
-        if (len == Reader.SIGN_VARIABLE) {
-            int size = 0;
-            long[] data = new long[8];
-            while (in.hasNext()) {
-                if (size >= data.length) {
-                    long[] newdata = new long[data.length + 4];
-                    System.arraycopy(data, 0, newdata, 0, size);
-                    data = newdata;
-                }
-                data[size++] = in.readLong();
+        int size = 0;
+        long[] data = new long[8];
+        while (in.hasNext()) {
+            if (size >= data.length) {
+                long[] newdata = new long[data.length + 4];
+                System.arraycopy(data, 0, newdata, 0, size);
+                data = newdata;
             }
-            in.readArrayE();
-            long[] newdata = new long[size];
-            System.arraycopy(data, 0, newdata, 0, size);
-            return newdata;
-        } else {
-            long[] values = new long[len];
-            for (int i = 0; i < values.length; i++) {
-                values[i] = in.readLong();
-            }
-            in.readArrayE();
-            return values;
+            data[size++] = in.readLong();
         }
+        in.readArrayE();
+        long[] newdata = new long[size];
+        System.arraycopy(data, 0, newdata, 0, size);
+        return newdata;
     }
 
     public static final class LongStreamSimpledCoder<R extends Reader, W extends Writer>
diff --git a/src/main/java/org/redkale/convert/ext/ShortArraySimpledCoder.java b/src/main/java/org/redkale/convert/ext/ShortArraySimpledCoder.java
index a75769932..7beef6169 100644
--- a/src/main/java/org/redkale/convert/ext/ShortArraySimpledCoder.java
+++ b/src/main/java/org/redkale/convert/ext/ShortArraySimpledCoder.java
@@ -40,32 +40,22 @@ public final class ShortArraySimpledCoder<R extends Reader, W extends Writer> ex
 
     @Override
     public short[] convertFrom(R in) {
-        int len = in.readArrayB(ShortSimpledCoder.instance);
-        if (len == Reader.SIGN_NULL) {
+        if (!in.readArrayB(ShortSimpledCoder.instance)) {
             return null;
         }
-        if (len == Reader.SIGN_VARIABLE) {
-            int size = 0;
-            short[] data = new short[8];
-            while (in.hasNext()) {
-                if (size >= data.length) {
-                    short[] newdata = new short[data.length + 4];
-                    System.arraycopy(data, 0, newdata, 0, size);
-                    data = newdata;
-                }
-                data[size++] = in.readShort();
+        int size = 0;
+        short[] data = new short[8];
+        while (in.hasNext()) {
+            if (size >= data.length) {
+                short[] newdata = new short[data.length + 4];
+                System.arraycopy(data, 0, newdata, 0, size);
+                data = newdata;
             }
-            in.readArrayE();
-            short[] newdata = new short[size];
-            System.arraycopy(data, 0, newdata, 0, size);
-            return newdata;
-        } else {
-            short[] values = new short[len];
-            for (int i = 0; i < values.length; i++) {
-                values[i] = in.readShort();
-            }
-            in.readArrayE();
-            return values;
+            data[size++] = in.readShort();
         }
+        in.readArrayE();
+        short[] newdata = new short[size];
+        System.arraycopy(data, 0, newdata, 0, size);
+        return newdata;
     }
 }
diff --git a/src/main/java/org/redkale/convert/ext/StringArraySimpledCoder.java b/src/main/java/org/redkale/convert/ext/StringArraySimpledCoder.java
index 3812e1061..70df490af 100644
--- a/src/main/java/org/redkale/convert/ext/StringArraySimpledCoder.java
+++ b/src/main/java/org/redkale/convert/ext/StringArraySimpledCoder.java
@@ -40,32 +40,22 @@ public final class StringArraySimpledCoder<R extends Reader, W extends Writer> e
 
     @Override
     public String[] convertFrom(R in) {
-        int len = in.readArrayB(StringSimpledCoder.instance);
-        if (len == Reader.SIGN_NULL) {
+        if (!in.readArrayB(StringSimpledCoder.instance)) {
             return null;
         }
-        if (len == Reader.SIGN_VARIABLE) {
-            int size = 0;
-            String[] data = new String[8];
-            while (in.hasNext()) {
-                if (size >= data.length) {
-                    String[] newdata = new String[data.length + 4];
-                    System.arraycopy(data, 0, newdata, 0, size);
-                    data = newdata;
-                }
-                data[size++] = in.readString();
+        int size = 0;
+        String[] data = new String[8];
+        while (in.hasNext()) {
+            if (size >= data.length) {
+                String[] newdata = new String[data.length + 4];
+                System.arraycopy(data, 0, newdata, 0, size);
+                data = newdata;
             }
-            in.readArrayE();
-            String[] newdata = new String[size];
-            System.arraycopy(data, 0, newdata, 0, size);
-            return newdata;
-        } else {
-            String[] values = new String[len];
-            for (int i = 0; i < values.length; i++) {
-                values[i] = in.readString();
-            }
-            in.readArrayE();
-            return values;
+            data[size++] = in.readString();
         }
+        in.readArrayE();
+        String[] newdata = new String[size];
+        System.arraycopy(data, 0, newdata, 0, size);
+        return newdata;
     }
 }
diff --git a/src/main/java/org/redkale/convert/json/JsonByteBufferReader.java b/src/main/java/org/redkale/convert/json/JsonByteBufferReader.java
index 498b74bd4..3f2c59afb 100644
--- a/src/main/java/org/redkale/convert/json/JsonByteBufferReader.java
+++ b/src/main/java/org/redkale/convert/json/JsonByteBufferReader.java
@@ -8,7 +8,6 @@ package org.redkale.convert.json;
 import java.nio.ByteBuffer;
 import java.nio.charset.UnmappableCharacterException;
 import org.redkale.convert.*;
-import static org.redkale.convert.Reader.*;
 import org.redkale.util.ByteTreeNode;
 
 /**
@@ -170,42 +169,43 @@ public class JsonByteBufferReader extends JsonReader {
     }
 
     /**
-     * 判断下一个非空白字符是否为{
+     * 读取对象，返回false表示对象为null
      *
-     * @return SIGN_VARIABLE 或 SIGN_NULL
+     * @param decoder Decodeable
+     * @return 是否存在对象
      */
     @Override
-    public final String readObjectB(final Class clazz) {
+    public final boolean readObjectB(Decodeable decoder) {
         char ch = nextGoodChar(true);
         if (ch == '{') {
-            return "";
+            return true;
         }
         if (ch == 'n' && nextChar() == 'u' && nextChar() == 'l' && nextChar() == 'l') {
-            return null;
+            return false;
         }
         if (ch == 'N' && nextChar() == 'U' && nextChar() == 'L' && nextChar() == 'L') {
-            return null;
+            return false;
         }
         throw new ConvertException("a json object must begin with '{' (position = " + position + ") but '" + ch + "'");
     }
 
     /**
-     * 判断下一个非空白字符是否为[
+     * 读取数组，返回false表示数组为null
      *
-     * @param decoder Decodeable
-     * @return SIGN_VARIABLE 或 SIGN_NULL
+     * @param componentDecoder Decodeable
+     * @return 是否存在对象
      */
     @Override
-    public final int readArrayB(Decodeable decoder) {
+    public final boolean readArrayB(Decodeable componentDecoder) {
         char ch = nextGoodChar(true);
         if (ch == '[' || ch == '{') {
-            return SIGN_VARIABLE;
+            return true;
         }
         if (ch == 'n' && nextChar() == 'u' && nextChar() == 'l' && nextChar() == 'l') {
-            return SIGN_NULL;
+            return false;
         }
         if (ch == 'N' && nextChar() == 'U' && nextChar() == 'L' && nextChar() == 'L') {
-            return SIGN_NULL;
+            return false;
         }
         int pos = this.position;
         throw new ConvertException("a json array must begin with '[' (position = " + pos + ") but '" + ch + "'");
diff --git a/src/main/java/org/redkale/convert/json/JsonMultiArrayDecoder.java b/src/main/java/org/redkale/convert/json/JsonMultiArrayDecoder.java
index e42c10e4b..5df54d98d 100644
--- a/src/main/java/org/redkale/convert/json/JsonMultiArrayDecoder.java
+++ b/src/main/java/org/redkale/convert/json/JsonMultiArrayDecoder.java
@@ -35,8 +35,7 @@ public class JsonMultiArrayDecoder implements Decodeable<JsonReader, Object[]> {
 
     @Override
     public Object[] convertFrom(JsonReader in) {
-        int len = in.readArrayB(null);
-        if (len == Reader.SIGN_NULL) {
+        if (!in.readArrayB(null)) {
             return null;
         }
         // len must be Reader.SIGN_VARIABLE
diff --git a/src/main/java/org/redkale/convert/json/JsonMultiImplDecoder.java b/src/main/java/org/redkale/convert/json/JsonMultiImplDecoder.java
index ca213b16a..ca8f601fb 100644
--- a/src/main/java/org/redkale/convert/json/JsonMultiImplDecoder.java
+++ b/src/main/java/org/redkale/convert/json/JsonMultiImplDecoder.java
@@ -102,8 +102,7 @@ public class JsonMultiImplDecoder<T> implements Decodeable<JsonReader, T> {
 
     @Override
     public T convertFrom(JsonReader in) {
-        final String clazz = in.readObjectB(null);
-        if (clazz == null) {
+        if (!in.readObjectB(this)) {
             return null;
         }
         ObjectDecoder decoder = this.firstDecoder;
@@ -150,7 +149,7 @@ public class JsonMultiImplDecoder<T> implements Decodeable<JsonReader, T> {
                 params[++index] = new Object[] {member.getAttribute(), member.read(in)};
             }
         }
-        in.readObjectE(null);
+        in.readObjectE();
         if (decoder.getConstructorMembers() == null) { // 空构造函数
             T result = (T) decoder.getCreator().create();
             for (int i = 0; i <= index; i++) {
diff --git a/src/main/java/org/redkale/convert/json/JsonReader.java b/src/main/java/org/redkale/convert/json/JsonReader.java
index e01007d44..818d86e1f 100644
--- a/src/main/java/org/redkale/convert/json/JsonReader.java
+++ b/src/main/java/org/redkale/convert/json/JsonReader.java
@@ -8,7 +8,6 @@ package org.redkale.convert.json;
 import java.nio.charset.StandardCharsets;
 import java.util.*;
 import org.redkale.convert.*;
-import static org.redkale.convert.Reader.*;
 import org.redkale.util.ByteTreeNode;
 import org.redkale.util.Utility;
 
@@ -270,75 +269,58 @@ public class JsonReader extends Reader {
     }
 
     /**
-     * 判断下一个非空白字符是否为{
+     * 读取对象，返回false表示对象为null
      *
-     * @param clazz 类名
-     * @return 返回 null 表示对象为null， 返回空字符串表示当前class与返回的class一致，返回非空字符串表示class是当前class的子类。
+     * @param decoder Decodeable
+     * @return 是否存在对象
      */
     @Override
-    public String readObjectB(final Class clazz) {
+    public boolean readObjectB(final Decodeable decoder) {
         if (this.text.length == 0) {
-            return null;
+            return false;
         }
         char ch = nextGoodChar(true);
         if (ch == '{') {
-            return "";
+            return true;
         }
         if (ch == 'n' && text[++position] == 'u' && text[++position] == 'l' && text[++position] == 'l') {
-            return null;
+            return false;
         }
         if (ch == 'N' && text[++position] == 'U' && text[++position] == 'L' && text[++position] == 'L') {
-            return null;
+            return false;
         }
         throw new ConvertException("a json object must begin with '{' (position = " + position + ") but '" + ch
                 + "' in " + new String(this.text));
     }
 
     @Override
-    public final void readObjectE(final Class clazz) {
+    public final void readObjectE() {
         // do nothing
     }
 
     /**
-     * 判断下一个非空白字符是否为{
-     *
-     * @param keyDecoder Decodeable
-     * @param valuedecoder Decodeable
-     * @return SIGN_VARIABLE 或 SIGN_NULL
-     */
-    @Override
-    public final int readMapB(Decodeable keyDecoder, Decodeable valuedecoder) {
-        return readArrayB(keyDecoder);
-    }
-
-    @Override
-    public final void readMapE() {
-        // do nothing
-    }
-
-    /**
-     * 判断下一个非空白字符是否为[
+     * 读取数组，返回false表示数组为null
      *
      * @param componentDecoder Decodeable
-     * @return SIGN_VARIABLE 或 SIGN_NULL
+     * @return 是否存在对象
      */
     @Override
-    public int readArrayB(Decodeable componentDecoder) {
+    public boolean readArrayB(Decodeable componentDecoder) {
         if (this.text.length == 0) {
-            return SIGN_NULL;
+            return false;
         }
         char ch = nextGoodChar(true);
         if (ch == '[') {
-            return SIGN_VARIABLE;
+            return true;
         }
         if (ch == '{') {
-            return SIGN_VARIABLE;
+            return true;
         }
         if (ch == 'n' && text[++position] == 'u' && text[++position] == 'l' && text[++position] == 'l') {
-            return SIGN_NULL;
+            return false;
         }
         if (ch == 'N' && text[++position] == 'U' && text[++position] == 'L' && text[++position] == 'L') {
-            return SIGN_NULL;
+            return false;
         }
         throw new ConvertException("a json array text must begin with '[' (position = " + position + ") but '" + ch
                 + "' in " + new String(this.text));
@@ -349,6 +331,23 @@ public class JsonReader extends Reader {
         // do nothing
     }
 
+    /**
+     * 读取map，返回false表示map为null
+     *
+     * @param keyDecoder Decodeable
+     * @param valueDecoder Decodeable
+     * @return 是否存在对象
+     */
+    @Override
+    public final boolean readMapB(Decodeable keyDecoder, Decodeable valueDecoder) {
+        return readArrayB(keyDecoder);
+    }
+
+    @Override
+    public final void readMapE() {
+        // do nothing
+    }
+
     /** 判断下一个非空白字符是否: */
     @Override
     public void readColon() {
@@ -720,33 +719,24 @@ public class JsonReader extends Reader {
 
     @Override
     public final byte[] readByteArray() {
-        int len = readArrayB(null);
-        if (len == Reader.SIGN_NULL) {
+        boolean has = readArrayB(null);
+        if (!has) {
             return null;
         }
-        if (len == Reader.SIGN_VARIABLE) {
-            int size = 0;
-            byte[] data = new byte[8];
-            while (hasNext()) {
-                if (size >= data.length) {
-                    byte[] newdata = new byte[data.length + 4];
-                    System.arraycopy(data, 0, newdata, 0, size);
-                    data = newdata;
-                }
-                data[size++] = readByte();
+        int size = 0;
+        byte[] data = new byte[8];
+        while (hasNext()) {
+            if (size >= data.length) {
+                byte[] newdata = new byte[data.length + 4];
+                System.arraycopy(data, 0, newdata, 0, size);
+                data = newdata;
             }
-            readArrayE();
-            byte[] newdata = new byte[size];
-            System.arraycopy(data, 0, newdata, 0, size);
-            return newdata;
-        } else { // 固定长度
-            byte[] values = new byte[len];
-            for (int i = 0; i < values.length; i++) {
-                values[i] = readByte();
-            }
-            readArrayE();
-            return values;
+            data[size++] = readByte();
         }
+        readArrayE();
+        byte[] newdata = new byte[size];
+        System.arraycopy(data, 0, newdata, 0, size);
+        return newdata;
     }
 
     @Override
diff --git a/src/main/java/org/redkale/convert/pb/ProtobufReader.java b/src/main/java/org/redkale/convert/pb/ProtobufReader.java
index e79ea5d74..b088730b9 100644
--- a/src/main/java/org/redkale/convert/pb/ProtobufReader.java
+++ b/src/main/java/org/redkale/convert/pb/ProtobufReader.java
@@ -110,22 +110,12 @@ public class ProtobufReader extends Reader {
     }
 
     @Override
-    public final String readObjectB(final Class clazz) {
-        return hasNext() ? "" : null;
+    public final boolean readObjectB(final Decodeable decoder) {
+        return hasNext();
     }
 
     @Override
-    public final void readObjectE(final Class clazz) {
-        // do nothing
-    }
-
-    @Override
-    public final int readMapB(Decodeable keyDecoder, Decodeable valueDecoder) {
-        return Reader.SIGN_VARIABLE;
-    }
-
-    @Override
-    public final void readMapE() {
+    public final void readObjectE() {
         // do nothing
     }
 
@@ -133,11 +123,11 @@ public class ProtobufReader extends Reader {
      * 判断下一个非空白字符是否为[
      *
      * @param componentDecoder Decodeable
-     * @return SIGN_VARIABLE 或 SIGN_NULL
+     * @return 是否存在对象
      */
     @Override
-    public final int readArrayB(Decodeable componentDecoder) {
-        return Reader.SIGN_VARIABLE;
+    public final boolean readArrayB(Decodeable componentDecoder) {
+        return true;
     }
 
     @Override
@@ -145,6 +135,16 @@ public class ProtobufReader extends Reader {
         // do nothing
     }
 
+    @Override
+    public final boolean readMapB(Decodeable keyDecoder, Decodeable valueDecoder) {
+        return true;
+    }
+
+    @Override
+    public final void readMapE() {
+        // do nothing
+    }
+
     /** 判断下一个非空白字节是否: */
     @Override
     public final void readColon() {
diff --git a/src/test/java/org/redkale/test/convert/InnerCoderEntityTest.java b/src/test/java/org/redkale/test/convert/InnerCoderEntityTest.java
index 19cb550ef..680d64fbf 100644
--- a/src/test/java/org/redkale/test/convert/InnerCoderEntityTest.java
+++ b/src/test/java/org/redkale/test/convert/InnerCoderEntityTest.java
@@ -106,7 +106,9 @@ public class InnerCoderEntityTest {
 
                 @Override
                 public InnerCoderEntity convertFrom(Reader in) {
-                    if (in.readObjectB(InnerCoderEntity.class) == null) return null;
+                    if (!in.readObjectB(this)) {
+                        return null;
+                    }
                     int index = 0;
                     final Object[] params = new Object[deMembers.length];
                     while (in.hasNext()) {
@@ -118,7 +120,7 @@ public class InnerCoderEntityTest {
                             params[index++] = member.read(in);
                         }
                     }
-                    in.readObjectE(InnerCoderEntity.class);
+                    in.readObjectE();
                     return InnerCoderEntity.create(params[0] == null ? 0 : (Integer) params[0], (String) params[1]);
                 }
             };