add http engine

hutool-core/src/main/java/cn/hutool/core/io/EmptyInputStream.java

@@ -0,0 +1,61 @@
+package cn.hutool.core.io;
+
+import java.io.InputStream;
+
+/**
+ * 空的流
+ *
+ * @author looly
+ */
+@SuppressWarnings("NullableProblems")
+public final class EmptyInputStream extends InputStream {
+	/**
+	 * 单例实例
+	 */
+	public static final EmptyInputStream INSTANCE = new EmptyInputStream();
+
+	private EmptyInputStream() {
+	}
+
+	@Override
+	public int available() {
+		return 0;
+	}
+
+	@Override
+	public void close() {
+	}
+
+	@Override
+	public void mark(final int readLimit) {
+	}
+
+	@Override
+	public boolean markSupported() {
+		return true;
+	}
+
+	@Override
+	public int read() {
+		return -1;
+	}
+
+	@Override
+	public int read(final byte[] buf) {
+		return -1;
+	}
+
+	@Override
+	public int read(final byte[] buf, final int off, final int len) {
+		return -1;
+	}
+
+	@Override
+	public void reset() {
+	}
+
+	@Override
+	public long skip(final long n) {
+		return 0L;
+	}
+}

hutool-core/src/main/java/cn/hutool/core/io/resource/HttpResource.java

@@ -0,0 +1,55 @@
+package cn.hutool.core.io.resource;
+
+import cn.hutool.core.lang.Assert;
+
+import java.io.InputStream;
+import java.io.Serializable;
+import java.net.URL;
+
+/**
+ * HTTP资源，用于自定义表单数据，可自定义Content-Type
+ *
+ * @author looly
+ * @since 5.7.17
+ */
+public class HttpResource implements Resource, Serializable {
+	private static final long serialVersionUID = 1L;
+
+	private final Resource resource;
+	private final String contentType;
+
+	/**
+	 * 构造
+	 *
+	 * @param resource    资源，非空
+	 * @param contentType Content-Type类型，{@code null}表示不设置
+	 */
+	public HttpResource(final Resource resource, final String contentType) {
+		this.resource = Assert.notNull(resource, "Resource must be not null !");
+		this.contentType = contentType;
+	}
+
+	@Override
+	public String getName() {
+		return resource.getName();
+	}
+
+	@Override
+	public URL getUrl() {
+		return resource.getUrl();
+	}
+
+	@Override
+	public InputStream getStream() {
+		return resource.getStream();
+	}
+
+	/**
+	 * 获取自定义Content-Type类型
+	 *
+	 * @return Content-Type类型
+	 */
+	public String getContentType() {
+		return this.contentType;
+	}
+}