---
title: "Send custom HTTP headers"
description: "Learn how to send custom HTTP headers when converting HTML to PDF using Java and the Netty library. This guide offers detailed steps with code samples in Java and the Netty library, showing how to customize request headers."
language: 'Java'
library: 'Netty'
property: 'headers'
output: 'pdf'
related: ['accessing-secured-pages', 'using-cookies']
default: false
---

In this guide, we'll show you how to send custom HTTP headers when converting HTML to PDF using Java and the Netty library.

When converting HTML to PDF, you might need to send custom HTTP headers to access protected resources or provide additional information.

```java
import io.netty.bootstrap.Bootstrap;
import io.netty.channel.*;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioSocketChannel;
import io.netty.handler.codec.http.*;
import io.netty.util.CharsetUtil;

// You can get an API key at https://pdfshift.io
String apiKey = "sk_xxxxxxxxxxxx";

EventLoopGroup group = new NioEventLoopGroup();
try {
    Bootstrap b = new Bootstrap();
    b.group(group)
        .channel(NioSocketChannel.class)
        .handler(new ChannelInitializer<SocketChannel>() {
            @Override
            public void initChannel(SocketChannel ch) {
                ChannelPipeline p = ch.pipeline();
                p.addLast(new HttpClientCodec());
                p.addLast(new HttpObjectAggregator(1024 * 1024));
            }
        });

    Channel ch = b.connect("api.pdfshift.io", 443).sync().channel();

    FullHttpRequest request = new DefaultFullHttpRequest(
        HttpVersion.HTTP_1_1, HttpMethod.POST, "/v3/convert/pdf");
    
    request.headers().set(HttpHeaderNames.HOST, "api.pdfshift.io");
    request.headers().set("X-API-Key", apiKey);
    request.headers().set(HttpHeaderNames.CONTENT_TYPE, "application/json");
    
    String payload = "{\n" +
        "  \"source\": \"https://www.example.com\",\n" +
        "  \"headers\": {\n" +
        "    \"authorization\": \"Bearer token123\",\n" +
        "    \"user-agent\": \"MyApp/1.0\"\n" +
        "  }\n" +
        "}";
    
    request.content().writeBytes(payload.getBytes(CharsetUtil.UTF_8));
    request.headers().setInt(HttpHeaderNames.CONTENT_LENGTH, request.content().readableBytes());

    ChannelFuture f = ch.writeAndFlush(request);
    f.addListener(ChannelFutureListener.CLOSE);
    
    // Handle response and save PDF...
    
    System.out.println("The PDF document was generated and saved to result.pdf");
} finally {
    group.shutdownGracefully();
}
```

This allows you to customize the HTTP requests sent to the source URL.