io.trino.gateway.proxyserver.wrapper.MultiReadHttpServletRequest Maven / Gradle / Ivy

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/*
 * 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 io.trino.gateway.proxyserver.wrapper;

import jakarta.servlet.ReadListener;
import jakarta.servlet.ServletInputStream;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletRequestWrapper;

import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.util.Collections;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class MultiReadHttpServletRequest
        extends HttpServletRequestWrapper
{
    private final byte[] content;
    private final Map headerMap = new HashMap<>();

    public static void copy(InputStream in, OutputStream out)
            throws IOException
    {
        byte[] buffer = new byte[1024];
        while (true) {
            int bytesRead = in.read(buffer);
            if (bytesRead == -1) {
                break;
            }
            out.write(buffer, 0, bytesRead);
        }
    }

    public MultiReadHttpServletRequest(HttpServletRequest request)
            throws IOException
    {
        super(request);
        ByteArrayOutputStream bodyInOutputStream = new ByteArrayOutputStream();
        copy(request.getInputStream(), bodyInOutputStream);
        content = bodyInOutputStream.toByteArray();
    }

    /**
     * add a header with given name and value.
     */
    public void addHeader(String name, String value)
    {
        headerMap.put(name, value);
    }

    @Override
    public String getHeader(String name)
    {
        String headerValue = super.getHeader(name);
        if (headerMap.containsKey(name)) {
            headerValue = headerMap.get(name);
        }
        return headerValue;
    }

    /**
     * get the header names.
     */
    @Override
    public Enumeration getHeaderNames()
    {
        List names = Collections.list(super.getHeaderNames());
        for (String name : headerMap.keySet()) {
            names.add(name);
        }
        return Collections.enumeration(names);
    }

    @Override
    public Enumeration getHeaders(String name)
    {
        List values = Collections.list(super.getHeaders(name));
        if (headerMap.containsKey(name)) {
            values.add(headerMap.get(name));
        }
        return Collections.enumeration(values);
    }

    @Override
    public ServletInputStream getInputStream()
            throws IOException
    {
        final ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(content);
        return new ServletInputStream()
        {
            @Override
            public boolean isFinished()
            {
                return false;
            }

            @Override
            public boolean isReady()
            {
                return false;
            }

            @Override
            public void setReadListener(ReadListener readListener) {}

            @Override
            public int read()
                    throws IOException
            {
                return byteArrayInputStream.read();
            }
        };
    }

    @Override
    public BufferedReader getReader()
            throws IOException
    {
        return new BufferedReader(new InputStreamReader(this.getInputStream()));
    }
}