---
title: "Adding a text watermark"
description: "Learn how to add text watermarks to your PDFs using Java and the Netty library. This guide offers detailed steps with code samples in Java and the Netty library, showing how to apply text watermarks to protect your documents."
language: 'Java'
library: 'Netty'
property: 'watermark'
output: 'pdf'
related: ['adding-an-image-watermark', 'protecting-the-generated-pdf']
default: false
---

In this guide, we'll show you how to add text watermarks to your PDFs using Java and the Netty library.

When generating PDFs, you might want to add text watermarks to your documents for protection or branding purposes.

```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" +
        "  \"watermark\": {\n" +
        "    \"text\": \"CONFIDENTIAL\",\n" +
        "    \"opacity\": 0.3,\n" +
        "    \"size\": \"20px\",\n" +
        "    \"color\": \"#000000\"\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 add textual protection to your documents with customizable text.