/*
* Copyright 2002-2010 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
*
* http://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.http.client;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import org.springframework.http.HttpHeaders;
import org.springframework.util.Assert;
/**
* Abstract base for {@link ClientHttpRequest} that makes sure that headers and body are not written multiple times.
*
* @author Arjen Poutsma
* @since 3.0
*/
public abstract class AbstractClientHttpRequest implements ClientHttpRequest {
private boolean executed = false;
private final HttpHeaders headers = new HttpHeaders();
private final ByteArrayOutputStream bufferedOutput = new ByteArrayOutputStream();
public final HttpHeaders getHeaders() {
return executed ? HttpHeaders.readOnlyHttpHeaders(headers) : this.headers;
}
public final OutputStream getBody() throws IOException {
checkExecuted();
return this.bufferedOutput;
}
public final ClientHttpResponse execute() throws IOException {
checkExecuted();
ClientHttpResponse result = executeInternal(this.headers, this.bufferedOutput.toByteArray());
this.executed = true;
return result;
}
private void checkExecuted() {
Assert.state(!this.executed, "ClientHttpRequest already executed");
}
/**
* Abstract template method that writes the given headers and content to the HTTP request.
* @param headers the HTTP headers
* @param bufferedOutput the body content
* @return the response object for the executed request
*/
protected abstract ClientHttpResponse executeInternal(HttpHeaders headers, byte[] bufferedOutput)
throws IOException;
}
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