diff --git a/src/com/wentch/redkale/convert/bson/BsonByteBufferWriter.java b/src/com/wentch/redkale/convert/bson/BsonByteBufferWriter.java
new file mode 100644
index 000000000..ac2356717
--- /dev/null
+++ b/src/com/wentch/redkale/convert/bson/BsonByteBufferWriter.java
@@ -0,0 +1,185 @@
+/*
+ * To change this license header, choose License Headers in Project Properties.
+ * To change this template file, choose Tools | Templates
+ * and open the template in the editor.
+ */
+package com.wentch.redkale.convert.bson;
+
+import java.nio.*;
+import java.nio.charset.*;
+import java.util.function.*;
+
+/**
+ *
+ * @author zhangjx
+ */
+public final class BsonByteBufferWriter extends BsonWriter {
+
+    private static final Charset UTF8 = Charset.forName("UTF-8");
+
+    private final Supplier<ByteBuffer> supplier;
+
+    private ByteBuffer[] buffers;
+
+    private int index;
+
+    public BsonByteBufferWriter(Supplier<ByteBuffer> supplier) {
+        this.supplier = supplier;
+    }
+
+    public ByteBuffer[] toBuffers() {
+        if (buffers == null) return new ByteBuffer[0];
+        for (int i = index; i < this.buffers.length; i++) {
+            ByteBuffer buf = this.buffers[i];
+            if (buf.position() != 0) buf.flip();
+        }
+        return this.buffers;
+    }
+
+    @Override
+    public byte[] toArray() {
+        if (buffers == null) return new byte[0];
+        int pos = 0;
+        byte[] bytes = new byte[this.count];
+        for (ByteBuffer buf : toBuffers()) {
+            int r = buf.remaining();
+            buf.get(bytes, pos, r);
+            buf.flip();
+            pos += r;
+        }
+        return bytes;
+    }
+
+    @Override
+    public ByteBuffer toBuffer() {
+        if (buffers == null) return null;
+        if (buffers.length == 1) return buffers[0];
+        final ByteBuffer rs = ByteBuffer.allocate(count);
+        for (ByteBuffer buf : toBuffers()) {
+            rs.put(buf);
+            buf.flip();
+        }
+        rs.flip();
+        return rs;
+    }
+
+    @Override
+    public void toBuffer(ByteBuffer buffer) {
+        throw new UnsupportedOperationException("Not supported yet.");
+    }
+
+    @Override
+    public int toBuffer(int offset, ByteBuffer buffer) {
+        throw new UnsupportedOperationException("Not supported yet.");
+    }
+
+    @Override
+    public String toString() {
+        return "bytes[" + count() + "]";
+    }
+
+    @Override
+    public BsonByteBufferWriter setTiny(boolean tiny) {
+        this.tiny = tiny;
+        return this;
+    }
+
+    @Override
+    public BsonByteBufferWriter fillRange(final int len) {
+        ByteBuffer buffer = this.buffers[index];
+        if (expand(len) == 0) {
+            buffer.position(buffer.position() + len);
+        } else {
+            int remain = len;  //还剩多少没有写
+            while (remain > 0) {
+                final int br = buffer.remaining();
+                if (remain > br) { //一个buffer写不完
+                    buffer.position(buffer.position() + br);
+                    buffer = nextByteBuffer();
+                    remain -= br;
+                } else {
+                    buffer.position(buffer.position() + remain);
+                    remain = 0;
+                }
+            }
+        }
+        this.count += len;
+        return this;
+    }
+
+    private int expand(final int byteLength) {
+        if (this.buffers == null) {
+            this.index = 0;
+            this.buffers = new ByteBuffer[]{supplier.get()};
+        }
+        ByteBuffer buffer = this.buffers[index];
+        if (!buffer.hasRemaining()) {
+            buffer.flip();
+            buffer = supplier.get();
+            ByteBuffer[] bufs = new ByteBuffer[this.buffers.length + 1];
+            System.arraycopy(this.buffers, 0, bufs, 0, this.buffers.length);
+            bufs[this.buffers.length] = buffer;
+            this.buffers = bufs;
+            this.index++;
+        }
+        int len = buffer.remaining();
+        int size = 0;
+        while (len < byteLength) {
+            buffer = supplier.get();
+            ByteBuffer[] bufs = new ByteBuffer[this.buffers.length + 1];
+            System.arraycopy(this.buffers, 0, bufs, 0, this.buffers.length);
+            bufs[this.buffers.length] = buffer;
+            this.buffers = bufs;
+            len += buffer.remaining();
+            size++;
+        }
+        return size;
+    }
+
+    @Override
+    public int rewriteTo(int position, byte... chs) {
+        return position += chs.length;
+    }
+
+    @Override
+    public void writeTo(final byte[] chs, final int start, final int len) {
+        if (expand(len) == 0) {
+            this.buffers[index].put(chs, start, len);
+        } else {
+            ByteBuffer buffer = this.buffers[index];
+            final int end = start + len;
+            int remain = len;  //还剩多少没有写
+            while (remain > 0) {
+                final int br = buffer.remaining();
+                if (remain > br) { //一个buffer写不完
+                    buffer.put(chs, end - remain, br);
+                    buffer = nextByteBuffer();
+                    remain -= br;
+                } else {
+                    buffer.put(chs, end - remain, remain);
+                    remain = 0;
+                }
+            }
+        }
+        this.count += len;
+    }
+
+    private ByteBuffer nextByteBuffer() {
+        this.buffers[this.index].flip();
+        return this.buffers[++this.index];
+    }
+
+    @Override
+    public void writeTo(final byte ch) {
+        expand(1);
+        this.buffers[index].put(ch);
+        count++;
+    }
+
+    @Override
+    protected boolean recycle() {
+        this.index = 0;
+        this.buffers = null;
+        return false;
+    }
+}
diff --git a/src/com/wentch/redkale/convert/bson/BsonConvert.java b/src/com/wentch/redkale/convert/bson/BsonConvert.java
index e69a90034..939a20231 100644
--- a/src/com/wentch/redkale/convert/bson/BsonConvert.java
+++ b/src/com/wentch/redkale/convert/bson/BsonConvert.java
@@ -9,6 +9,7 @@ import com.wentch.redkale.convert.*;
 import com.wentch.redkale.util.*;
 import java.lang.reflect.*;
 import java.nio.*;
+import java.util.function.*;
 
 /**
  * BSON协议格式: 
@@ -95,6 +96,28 @@ public final class BsonConvert extends Convert<BsonReader, BsonWriter> {
         factory.loadEncoder(type).convertTo(out, value);
     }
 
+    public ByteBuffer[] convertTo(final Supplier<ByteBuffer> supplier, final Type type, Object value) {
+        if (supplier == null || type == null) return null;
+        BsonByteBufferWriter out = new BsonByteBufferWriter(supplier);
+        if (value == null) {
+            out.writeNull();
+        } else {
+            factory.loadEncoder(type).convertTo(out, value);
+        }
+        return out.toBuffers();
+    }
+
+    public ByteBuffer[] convertTo(final Supplier<ByteBuffer> supplier, Object value) {
+        if (supplier == null) return null;
+        BsonByteBufferWriter out = new BsonByteBufferWriter(supplier);
+        if (value == null) {
+            out.writeNull();
+        } else {
+            factory.loadEncoder(value.getClass()).convertTo(out, value);
+        }
+        return out.toBuffers();
+    }
+
     public void convertTo(final BsonWriter out, Object value) {
         if (value == null) {
             out.writeNull();
diff --git a/src/com/wentch/redkale/convert/bson/BsonWriter.java b/src/com/wentch/redkale/convert/bson/BsonWriter.java
index eeb22efcd..16b86e3da 100644
--- a/src/com/wentch/redkale/convert/bson/BsonWriter.java
+++ b/src/com/wentch/redkale/convert/bson/BsonWriter.java
@@ -13,14 +13,14 @@ import java.nio.*;
  *
  * @author zhangjx
  */
-public final class BsonWriter implements Writer {
+public class BsonWriter implements Writer {
 
     private static final int defaultSize = Integer.getInteger("convert.bson.writer.buffer.defsize", 1024);
 
-    protected int count;
-
     private byte[] content;
 
+    protected int count;
+
     protected boolean tiny;
 
     public static ObjectPool<BsonWriter> createPool(int max) {
@@ -58,7 +58,7 @@ public final class BsonWriter implements Writer {
     }
 
     @Override
-    public boolean isTiny() {
+    public final boolean isTiny() {
         return tiny;
     }
 
@@ -75,7 +75,7 @@ public final class BsonWriter implements Writer {
      * @param len
      * @return
      */
-    public byte[] expand(int len) {
+    private byte[] expand(int len) {
         int newcount = count + len;
         if (newcount <= content.length) return content;
         byte[] newdata = new byte[Math.max(content.length * 3 / 2, newcount)];
@@ -96,22 +96,22 @@ public final class BsonWriter implements Writer {
         return position + chs.length;
     }
 
-    public int rewriteTo(int position, short value) {
+    public final int rewriteTo(int position, short value) {
         rewriteTo(position, (byte) (value >> 8), (byte) value);
         return position + 2;
     }
 
-    public int rewriteTo(int position, char value) {
+    public final int rewriteTo(int position, char value) {
         rewriteTo(position, (byte) ((value & 0xFF00) >> 8), (byte) (value & 0xFF));
         return position + 2;
     }
 
-    public int rewriteTo(int position, int value) {
+    public final int rewriteTo(int position, int value) {
         rewriteTo(position, (byte) (value >> 24), (byte) (value >> 16), (byte) (value >> 8), (byte) value);
         return position + 4;
     }
 
-    public int rewriteTo(int position, long value) {
+    public final int rewriteTo(int position, long value) {
         rewriteTo(position, (byte) (value >> 56), (byte) (value >> 48), (byte) (value >> 40), (byte) (value >> 32),
                 (byte) (value >> 24), (byte) (value >> 16), (byte) (value >> 8), (byte) value);
         return position + 8;
@@ -128,15 +128,11 @@ public final class BsonWriter implements Writer {
         content[count++] = ch;
     }
 
-    public void writeTo(final byte... chs) {
-        int len = chs.length;
-        expand(len);
-        System.arraycopy(chs, 0, content, count, len);
-        count += len;
+    public final void writeTo(final byte... chs) {
+        writeTo(chs, 0, chs.length);
     }
 
-    public void writeTo(final byte[] chs, final int start, final int end) {
-        int len = end - start;
+    public void writeTo(final byte[] chs, final int start, final int len) {
         expand(len);
         System.arraycopy(chs, start, content, count, len);
         count += len;
@@ -150,68 +146,59 @@ public final class BsonWriter implements Writer {
         return true;
     }
 
-    //------------------------------------------------------------------------
-    public int position() {
-        return this.count;
-    }
-
-    public final int count() {
-        return this.count;
-    }
-
-    public final void count(int count) {
-        if (count >= 0) this.count = count;
-    }
-
-    //-----------------------------------------------------------------------
     @Override
     public String toString() {
         return new String(content, 0, count);
     }
 
+    //------------------------------------------------------------------------
+    public final int count() {
+        return this.count;
+    }
+
     @Override
-    public void writeBoolean(boolean value) {
+    public final void writeBoolean(boolean value) {
         writeTo(value ? (byte) 1 : (byte) 0);
     }
 
     @Override
-    public void writeByte(byte value) {
+    public final void writeByte(byte value) {
         writeTo(value);
     }
 
     @Override
-    public void writeChar(final char value) {
+    public final void writeChar(final char value) {
         writeTo((byte) ((value & 0xFF00) >> 8), (byte) (value & 0xFF));
     }
 
     @Override
-    public void writeShort(short value) {
+    public final void writeShort(short value) {
         writeTo((byte) (value >> 8), (byte) value);
     }
 
     @Override
-    public void writeInt(int value) {
+    public final void writeInt(int value) {
         writeTo((byte) (value >> 24), (byte) (value >> 16), (byte) (value >> 8), (byte) value);
     }
 
     @Override
-    public void writeLong(long value) {
+    public final void writeLong(long value) {
         writeTo((byte) (value >> 56), (byte) (value >> 48), (byte) (value >> 40), (byte) (value >> 32),
                 (byte) (value >> 24), (byte) (value >> 16), (byte) (value >> 8), (byte) value);
     }
 
     @Override
-    public void writeFloat(float value) {
+    public final void writeFloat(float value) {
         writeInt(Float.floatToIntBits(value));
     }
 
     @Override
-    public void writeDouble(double value) {
+    public final void writeDouble(double value) {
         writeLong(Double.doubleToLongBits(value));
     }
 
     @Override
-    public void wirteClassName(String clazz) {
+    public final void wirteClassName(String clazz) {
         writeSmallString(clazz == null ? "" : clazz);
     }
 
@@ -279,7 +266,7 @@ public final class BsonWriter implements Writer {
      * @param value
      */
     @Override
-    public void writeSmallString(String value) {
+    public final void writeSmallString(String value) {
         if (value.isEmpty()) {
             writeTo((byte) 0);
             return;
@@ -296,7 +283,7 @@ public final class BsonWriter implements Writer {
     }
 
     @Override
-    public void writeString(String value) {
+    public final void writeString(String value) {
         if (value == null) {
             writeInt(Reader.SIGN_NULL);
             return;
@@ -315,16 +302,16 @@ public final class BsonWriter implements Writer {
     }
 
     @Override
-    public void writeArrayB(int size) {
+    public final void writeArrayB(int size) {
         writeInt(size);
     }
 
     @Override
-    public void writeArrayMark() {
+    public final void writeArrayMark() {
     }
 
     @Override
-    public void writeArrayE() {
+    public final void writeArrayE() {
     }
 
     @Override
@@ -333,11 +320,11 @@ public final class BsonWriter implements Writer {
     }
 
     @Override
-    public void writeMapMark() {
+    public final void writeMapMark() {
     }
 
     @Override
-    public void writeMapE() {
+    public final void writeMapE() {
     }
 
 }
diff --git a/src/com/wentch/redkale/convert/json/JsonByteBufferWriter.java b/src/com/wentch/redkale/convert/json/JsonByteBufferWriter.java
index 864a28101..54a604956 100644
--- a/src/com/wentch/redkale/convert/json/JsonByteBufferWriter.java
+++ b/src/com/wentch/redkale/convert/json/JsonByteBufferWriter.java
@@ -40,13 +40,14 @@ public final class JsonByteBufferWriter extends JsonWriter {
     protected boolean recycle() {
         this.index = 0;
         this.buffers = null;
-        return true;
+        return false;
     }
 
     public ByteBuffer[] toBuffers() {
         if (buffers == null) return new ByteBuffer[0];
         for (int i = index; i < this.buffers.length; i++) {
-            this.buffers[i].flip();
+            ByteBuffer buf = this.buffers[i];
+            if (buf.position() != 0) buf.flip();
         }
         return this.buffers;
     }