fix code

hutool-http/src/main/java/org/dromara/hutool/http/client/Request.java

@@ -380,7 +380,7 @@ public class Request implements HeaderOperation<Request> {
 
 		// 根据内容赋值默认Content-Type
 		if (StrUtil.isBlank(header(HeaderName.CONTENT_TYPE))) {
-			header(HeaderName.CONTENT_TYPE, body.getContentType(charset()), true);
+			header(HeaderName.CONTENT_TYPE, body.contentType(charset()), true);
 		}
 
 		return this;

hutool-http/src/main/java/org/dromara/hutool/http/client/body/HttpBody.java

@@ -38,18 +38,27 @@ public interface HttpBody {
 	 *
 	 * @return Content-Type值
 	 */
-	String getContentType();
+	String contentType();
+
+	/**
+	 * 获取写出字节长度，未知为-1
+	 *
+	 * @return 长度
+	 */
+	default long contentLength() {
+		return -1;
+	}
 
 	/**
 	 * 获取指定编码的Content-Type，类似于：application/json;charset=UTF-8<br>
-	 * 如果{@link #getContentType()} 已经包含编码信息，则编码信息一致直接返回，否则替换为指定编码。
+	 * 如果{@link #contentType()} 已经包含编码信息，则编码信息一致直接返回，否则替换为指定编码。
 	 *
 	 * @param charset 编码
 	 * @return Content-Type
-	 * @see #getContentType()
+	 * @see #contentType()
 	 */
-	default String getContentType(final Charset charset) {
+	default String contentType(final Charset charset) {
-		String contentType = getContentType();
+		String contentType = contentType();
 		if (null == contentType) {
 			return null;
 		}

hutool-http/src/main/java/org/dromara/hutool/http/client/body/MultipartBody.java

@@ -80,14 +80,14 @@ public class MultipartBody extends FormBody<MultipartBody> {
 	 * @return Multipart的Content-Type类型
 	 */
 	@Override
-	public String getContentType() {
+	public String contentType() {
 		return CONTENT_TYPE_MULTIPART_PREFIX + boundary;
 	}
 
 	@Override
-	public String getContentType(final Charset charset) {
+	public String contentType(final Charset charset) {
 		// multipart的Content-Type头指定"Content-Type; boundary=XXXX"，编码无效
-		return getContentType();
+		return contentType();
 	}
 
 	/**

hutool-http/src/main/java/org/dromara/hutool/http/client/body/ResourceBody.java

@@ -67,7 +67,12 @@ public class ResourceBody implements HttpBody {
 	}
 
 	@Override
-	public String getContentType() {
+	public String contentType() {
 		return this.resource.getContentType();
 	}
+
+	@Override
+	public long contentLength() {
+		return resource.size();
+	}
 }

hutool-http/src/main/java/org/dromara/hutool/http/client/body/ResponseBody.java

@@ -54,10 +54,15 @@ public class ResponseBody implements HttpBody, Closeable {
 	}
 
 	@Override
-	public String getContentType() {
+	public String contentType() {
 		return response.header(HeaderName.CONTENT_TYPE);
 	}
 
+	@Override
+	public long contentLength() {
+		return response.contentLength();
+	}
+
 	@Override
 	public InputStream getStream() {
 		return this.bodyStream;

hutool-http/src/main/java/org/dromara/hutool/http/client/body/UrlEncodedFormBody.java

@@ -29,6 +29,8 @@ import java.util.Map;
  */
 public class UrlEncodedFormBody extends FormBody<UrlEncodedFormBody> {
 
+	private byte[] content;
+
 	/**
 	 * 创建 Http request body
 	 *
@@ -51,13 +53,38 @@ public class UrlEncodedFormBody extends FormBody<UrlEncodedFormBody> {
 	}
 
 	@Override
-	public void write(final OutputStream out) {
+	public UrlEncodedFormBody form(final String name, final Object value) {
-		final byte[] bytes = ByteUtil.toBytes(UrlQuery.of(form, UrlQuery.EncodeMode.FORM_URL_ENCODED).build(charset), charset);
+		// 有新键值对加入时，清空生成的字节
-		IoUtil.write(out, false, bytes);
+		if(null != this.content){
+			this.content = null;
+		}
+		return super.form(name, value);
 	}
 
 	@Override
-	public String getContentType() {
+	public void write(final OutputStream out) {
+		IoUtil.write(out, getGeneratedBytes());
+	}
+
+	@Override
+	public String contentType() {
 		return ContentType.FORM_URLENCODED.toString(charset);
 	}
+
+	@Override
+	public long contentLength() {
+		return getGeneratedBytes().length;
+	}
+
+	/**
+	 * 获取生成的字节数组
+	 *
+	 * @return 生成的字节数组
+	 */
+	private byte[] getGeneratedBytes() {
+		if (null == this.content) {
+			this.content = ByteUtil.toBytes(UrlQuery.of(form, UrlQuery.EncodeMode.FORM_URL_ENCODED).build(charset), charset);
+		}
+		return this.content;
+	}
 }

hutool-http/src/main/java/org/dromara/hutool/http/client/engine/httpclient4/HttpClient4BodyEntity.java

@@ -69,6 +69,6 @@ public class HttpClient4BodyEntity extends AbstractHttpEntity {
 
 	@Override
 	public long getContentLength() {
-		return -1;
+		return body.contentLength();
 	}
 }

hutool-http/src/main/java/org/dromara/hutool/http/client/engine/httpclient5/HttpClient5BodyEntity.java

@@ -66,6 +66,6 @@ public class HttpClient5BodyEntity extends AbstractHttpEntity {
 
 	@Override
 	public long getContentLength() {
-		return -1;
+		return body.contentLength();
 	}
 }

hutool-http/src/main/java/org/dromara/hutool/http/client/engine/okhttp/OkHttpRequestBody.java

@@ -16,6 +16,8 @@ import org.dromara.hutool.http.client.body.HttpBody;
 import okhttp3.MediaType;
 import okio.BufferedSink;
 
+import java.io.IOException;
+
 /**
  * OkHttp的请求体实现，通过{@link HttpBody}转换实现
  *
@@ -39,6 +41,11 @@ public class OkHttpRequestBody extends okhttp3.RequestBody {
 		return null;
 	}
 
+	@Override
+	public long contentLength() throws IOException {
+		return this.body.contentLength();
+	}
+
 	@Override
 	public void writeTo(final BufferedSink bufferedSink) {
 		body.writeClose(bufferedSink.outputStream());