要阻止爱普生热敏打印机的网络访问，可以使用以下代码示例：

1. 使用Python的requests库发送POST请求，将网络访问禁用：

import requests

printer_ip = "打印机IP地址"

# 禁用网络访问
payload = {
    "NETWORK_CONF": "DISABLE"
}

response = requests.post(f"http://{printer_ip}/WEBAPP/network_conf", data=payload)

if response.status_code == 200:
    print("网络访问已禁用")
else:
    print("禁用网络访问失败")

2. 使用Java的HttpClient库发送POST请求，将网络访问禁用：

import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.net.http.HttpHeaders;
import java.nio.charset.StandardCharsets;

public class EpsonPrinterNetworkAccess {
    public static void main(String[] args) {
        String printerIp = "打印机IP地址";
        
        // 禁用网络访问
        String payload = "NETWORK_CONF=DISABLE";
        
        HttpClient client = HttpClient.newHttpClient();
        HttpRequest request = HttpRequest.newBuilder()
                .uri(URI.create("http://" + printerIp + "/WEBAPP/network_conf"))
                .header("Content-Type", "application/x-www-form-urlencoded")
                .POST(HttpRequest.BodyPublishers.ofString(payload))
                .build();
        
        try {
            HttpResponse response = client.send(request, HttpResponse.BodyHandlers.ofString());
            if (response.statusCode() == 200) {
                System.out.println("网络访问已禁用");
            } else {
                System.out.println("禁用网络访问失败");
            }
        } catch (Exception e) {
            System.out.println("发送请求失败：" + e.getMessage());
        }
    }
}

请确保将代码示例中的 "打印机IP地址" 替换为实际的爱普生热敏打印机的IP地址。这些示例代码将通过发送POST请求到打印机的网络配置接口来禁用网络访问。