1、重写底层代码，解决积木报表导出数据较大时，请求报错问题：Exceeded limit on max bytes to buffer : 262144

src/main/java/org/springframework/core/codec/AbstractDataBufferDecoder.java

+/*
+ * Copyright 2002-2019 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.core.codec;
+
+import org.reactivestreams.Publisher;
+import org.springframework.core.ResolvableType;
+import org.springframework.core.io.buffer.DataBuffer;
+import org.springframework.core.io.buffer.DataBufferUtils;
+import org.springframework.lang.Nullable;
+import org.springframework.util.MimeType;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+
+import java.util.Map;
+
+/**
+ * 重写SpringWebFex底层 为了解决GateWay报错：Exceeded limit on max bytes to buffer : 262144 错误
+ * Abstract base class for {@code Decoder} implementations that can decode
+ * a {@code DataBuffer} directly to the target element type.
+ *
+ * <p>Sub-classes must implement {@link #decodeDataBuffer} to provide a way to
+ * transform a {@code DataBuffer} to the target data type. The default
+ * {@link #decode} implementation transforms each individual data buffer while
+ * {@link #decodeToMono} applies "reduce" and transforms the aggregated buffer.
+ *
+ * <p>Sub-classes can override {@link #decode} in order to split the input stream
+ * along different boundaries (e.g. on new line characters for {@code String})
+ * or always reduce to a single data buffer (e.g. {@code Resource}).
+ *
+ * @author Rossen Stoyanchev
+ * @since 5.0
+ * @param <T> the element type
+ *  https://blog.csdn.net/fujiakai/article/details/134972127
+ */
+@SuppressWarnings("deprecation")
+public abstract class AbstractDataBufferDecoder<T> extends AbstractDecoder<T> {
+
+	private int maxInMemorySize = 10*256 * 1024*10;
+
+
+	protected AbstractDataBufferDecoder(MimeType... supportedMimeTypes) {
+		super(supportedMimeTypes);
+	}
+
+
+	/**
+	 * Configure a limit on the number of bytes that can be buffered whenever
+	 * the input stream needs to be aggregated. This can be a result of
+	 * decoding to a single {@code DataBuffer},
+	 * {@link java.nio.ByteBuffer ByteBuffer}, {@code byte[]},
+	 * {@link org.springframework.core.io.Resource Resource}, {@code String}, etc.
+	 * It can also occur when splitting the input stream, e.g. delimited text,
+	 * in which case the limit applies to data buffered between delimiters.
+	 * <p>By default this is set to 256K.
+	 * @param byteCount the max number of bytes to buffer, or -1 for unlimited
+	 * @since 5.1.11
+	 */
+	public void setMaxInMemorySize(int byteCount) {
+		this.maxInMemorySize = byteCount;
+	}
+
+	/**
+	 * Return the {@link #setMaxInMemorySize configured} byte count limit.
+	 * @since 5.1.11
+	 */
+	public int getMaxInMemorySize() {
+		return this.maxInMemorySize;
+	}
+
+
+	@Override
+	public Flux<T> decode(Publisher<DataBuffer> input, ResolvableType elementType,
+			@Nullable MimeType mimeType, @Nullable Map<String, Object> hints) {
+
+		return Flux.from(input).map(buffer -> decodeDataBuffer(buffer, elementType, mimeType, hints));
+	}
+
+	@Override
+	public Mono<T> decodeToMono(Publisher<DataBuffer> input, ResolvableType elementType,
+			@Nullable MimeType mimeType, @Nullable Map<String, Object> hints) {
+
+		return DataBufferUtils.join(input, this.maxInMemorySize)
+				.map(buffer -> decodeDataBuffer(buffer, elementType, mimeType, hints));
+	}
+
+	/**
+	 * How to decode a {@code DataBuffer} to the target element type.
+	 * @deprecated as of 5.2, please implement
+	 * {@link #decode(DataBuffer, ResolvableType, MimeType, Map)} instead
+	 */
+	@Deprecated
+	@Nullable
+	protected T decodeDataBuffer(DataBuffer buffer, ResolvableType elementType,
+			@Nullable MimeType mimeType, @Nullable Map<String, Object> hints) {
+
+		return decode(buffer, elementType, mimeType, hints);
+	}
+
+}