diff --git a/src/main/java/org/redkale/net/AsyncIOGroup.java b/src/main/java/org/redkale/net/AsyncIOGroup.java
index 60503cfd1..d23324f7c 100644
--- a/src/main/java/org/redkale/net/AsyncIOGroup.java
+++ b/src/main/java/org/redkale/net/AsyncIOGroup.java
@@ -27,7 +27,7 @@ import org.redkale.util.*;
 @ResourceType(AsyncGroup.class)
 public class AsyncIOGroup extends AsyncGroup {
 
-    private boolean started;
+    private final AtomicBoolean started = new AtomicBoolean();
 
     private boolean skipClose;
 
@@ -108,20 +108,18 @@ public class AsyncIOGroup extends AsyncGroup {
 
     @Override
     public AsyncGroup start() {
-        if (started) {
-            return this;
-        }
         if (closed.get()) {
             throw new RedkaleException("group is closed");
         }
-        for (int i = 0; i < this.ioReadThreads.length; i++) {
-            this.ioReadThreads[i].start();
-            if (this.ioWriteThreads[i] != this.ioReadThreads[i]) {
-                this.ioWriteThreads[i].start();
+        if (started.compareAndSet(false, true)) {
+            for (int i = 0; i < this.ioReadThreads.length; i++) {
+                this.ioReadThreads[i].start();
+                if (this.ioWriteThreads[i] != this.ioReadThreads[i]) {
+                    this.ioWriteThreads[i].start();
+                }
             }
+            //connectThread用时才初始化
         }
-        //connectThread用时才初始化
-        started = true;
         return this;
     }
 
diff --git a/src/main/java/org/redkale/net/http/HttpHeaders.java b/src/main/java/org/redkale/net/http/HttpHeaders.java
index 8c8908c81..382d46aee 100644
--- a/src/main/java/org/redkale/net/http/HttpHeaders.java
+++ b/src/main/java/org/redkale/net/http/HttpHeaders.java
@@ -12,6 +12,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.function.BiConsumer;
+import java.util.function.Predicate;
 import org.redkale.convert.TextConvert;
 import org.redkale.convert.json.JsonConvert;
 import org.redkale.util.RedkaleException;
@@ -103,14 +104,21 @@ public class HttpHeaders implements RestHeaders, Serializable {
 
     @Override
     public void forEach(BiConsumer<String, String> consumer) {
+        forEach((Predicate) null, consumer);
+    }
+
+    @Override
+    public void forEach(Predicate<String> filter, BiConsumer<String, String> consumer) {
         if (map != null) {
             map.forEach((k, v) -> {
-                if (v instanceof Collection) {
-                    for (Object item : (Collection) v) {
-                        consumer.accept(k, item == null ? null : item.toString());
+                if (filter == null || filter.test(k)) {
+                    if (v instanceof Collection) {
+                        for (Object item : (Collection) v) {
+                            consumer.accept(k, item == null ? null : item.toString());
+                        }
+                    } else {
+                        consumer.accept(k, v == null ? null : v.toString());
                     }
-                } else {
-                    consumer.accept(k, v == null ? null : v.toString());
                 }
             });
         }
diff --git a/src/main/java/org/redkale/net/http/HttpSimpleClient.java b/src/main/java/org/redkale/net/http/HttpSimpleClient.java
index d79dfd42f..800381cb4 100644
--- a/src/main/java/org/redkale/net/http/HttpSimpleClient.java
+++ b/src/main/java/org/redkale/net/http/HttpSimpleClient.java
@@ -246,18 +246,17 @@ public class HttpSimpleClient extends Client<HttpSimpleConnection, HttpSimpleReq
         array.put((method.toUpperCase() + " " + (urlpos > 0 ? url.substring(urlpos) : "/") + " HTTP/1.1\r\n").getBytes(StandardCharsets.UTF_8));
         array.put(("Host: " + uri.getHost() + "\r\n").getBytes(StandardCharsets.UTF_8));
 
-        array.put(("Content-Length: " + (body == null ? 0 : body.length) + "\r\n").getBytes(StandardCharsets.UTF_8));
+        array.put(HttpSimpleRequest.contentLengthBytes(body));
         if (headers == null || !headers.containsIgnoreCase("User-Agent")) {
             array.put(header_bytes_useragent);
         }
-        if (headers == null || !headers.containsIgnoreCase("Connection")) {
-            array.put(header_bytes_connclose);
-        }
+        array.put(header_bytes_connclose);
         if (headers == null || !headers.containsIgnoreCase(Rest.REST_HEADER_TRACEID)) {
             array.put((Rest.REST_HEADER_TRACEID + ": " + traceid + "\r\n").getBytes(StandardCharsets.UTF_8));
         }
         if (headers != null) {
-            headers.forEach((k, v) -> array.put((k + ": " + v + "\r\n").getBytes(StandardCharsets.UTF_8)));
+            headers.forEach(k -> !k.equalsIgnoreCase("Connection") && !k.equalsIgnoreCase("Content-Length"),
+                (k, v) -> array.put((k + ": " + v + "\r\n").getBytes(StandardCharsets.UTF_8)));
         }
         array.put((byte) '\r', (byte) '\n');
         if (body != null) {
@@ -336,7 +335,7 @@ public class HttpSimpleClient extends Client<HttpSimpleConnection, HttpSimpleReq
         public void readInIOThread(CompletionHandler<Integer, ByteBuffer> handler) {
             this.channel.readInIOThread(handler);
         }
-        
+
         public void write(ByteTuple array, CompletionHandler<Integer, Void> handler) {
             this.channel.write(array, handler);
         }
diff --git a/src/main/java/org/redkale/net/http/HttpSimpleRequest.java b/src/main/java/org/redkale/net/http/HttpSimpleRequest.java
index 8ad98873e..ebf36fb6b 100644
--- a/src/main/java/org/redkale/net/http/HttpSimpleRequest.java
+++ b/src/main/java/org/redkale/net/http/HttpSimpleRequest.java
@@ -147,7 +147,8 @@ public class HttpSimpleRequest extends ClientRequest implements java.io.Serializ
         array.put(("Content-Type: " + contentType0 + "\r\n").getBytes(StandardCharsets.UTF_8));
         array.put(contentLengthBytes(clientBody));
         if (headers != null) {
-            headers.forEach((k, v) -> array.put((k + ": " + v + "\r\n").getBytes(StandardCharsets.UTF_8)));
+            headers.forEach(k -> !k.equalsIgnoreCase("Content-Type") && !k.equalsIgnoreCase("Content-Length"),
+                (k, v) -> array.put((k + ": " + v + "\r\n").getBytes(StandardCharsets.UTF_8)));
         }
         array.put((byte) '\r', (byte) '\n');
         //写body    
@@ -160,7 +161,7 @@ public class HttpSimpleRequest extends ClientRequest implements java.io.Serializ
         return headers != null && headers.containsIgnoreCase(name);
     }
 
-    protected byte[] contentLengthBytes(byte[] clientBody) {
+    protected static byte[] contentLengthBytes(byte[] clientBody) {
         int len = clientBody == null ? 0 : clientBody.length;
         if (len < contentLengthArray.length) {
             return contentLengthArray[len];
diff --git a/src/main/java/org/redkale/net/http/RestHeaders.java b/src/main/java/org/redkale/net/http/RestHeaders.java
index 1023c42a6..ddb555353 100644
--- a/src/main/java/org/redkale/net/http/RestHeaders.java
+++ b/src/main/java/org/redkale/net/http/RestHeaders.java
@@ -9,6 +9,7 @@ import java.io.Serializable;
 import java.util.List;
 import java.util.Map;
 import java.util.function.BiConsumer;
+import java.util.function.Predicate;
 
 /**
  * 用于RestService类的方法的参数获取HttpHeaders
@@ -30,6 +31,8 @@ public interface RestHeaders {
 
     public void forEach(BiConsumer<String, String> consumer);
 
+    public void forEach(Predicate<String> filter, BiConsumer<String, String> consumer);
+
     public String[] names();
 
     public boolean contains(String name);