PHP调用DeepSeek API的完整指南-牛翰网

简介

本文将介绍如何使用 PHP 调用 DeepSeek API，实现流式对话并保存对话记录。PHP 版本使用面向对象的方式实现，代码结构清晰，易于维护。

1. 环境准备

1.1 系统要求

PHP 7.0 或更高版本
PHP cURL 扩展
文件写入权限

1.2 项目结构

deepseek-project/
├── main.php          # 主程序
└── conversation.txt  # 对话记录文件

2. 完整代码实现

<?php

class DeepSeekChat {
    private $url = 'https://api.siliconflow.cn/v1/chat/completions';
    private $apiKey = 'YOUR_API_KEY';  // 替换为你的 API Key
    private $logFile = 'conversation.txt';

    public function __construct() {
        // 确保日志文件存在且可写
        if (!file_exists($this->logFile)) {
            touch($this->logFile);
        }
    }

    private function saveToFile($content, $isQuestion = false) {
        $timestamp = date('Y-m-d H:i:s');
        $text = $isQuestion 
            ? "\n[$timestamp] Question:\n$content\n\n[$timestamp] Answer:\n"
            : $content;
        
        file_put_contents($this->logFile, $text, FILE_APPEND);
    }

    private function processStreamingResponse($handle) {
        $buffer = '';
        while (!feof($handle)) {
            $chunk = fread($handle, 1024);
            $buffer .= $chunk;

            // 处理缓冲区中的每一行
            while (($pos = strpos($buffer, "\n")) !== false) {
                $line = substr($buffer, 0, $pos);
                $buffer = substr($buffer, $pos + 1);

                if (strlen(trim($line)) > 0) {
                    if (strpos($line, 'data: ') === 0) {
                        $data = substr($line, 6); // 移除 "data: " 前缀
                        if ($data === '[DONE]') {
                            continue;
                        }

                        $json = json_decode($data, true);
                        if ($json && isset($json['choices'][0]['delta']['content'])) {
                            $content = $json['choices'][0]['delta']['content'];
                            echo $content;
                            flush();
                            $this->saveToFile($content);
                        }
                    }
                }
            }
        }
    }

    public function chat() {
        while (true) {
            echo "\n请输入您的问题 (输入 q 退出): ";
            $question = trim(fgets(STDIN));

            if ($question === 'q') {
                echo "程序已退出\n";
                break;
            }

            // 保存问题
            $this->saveToFile($question, true);

            // 准备请求数据
            $data = [
                'model' => 'deepseek-ai/DeepSeek-V3',
                'messages' => [
                    [
                        'role' => 'user',
                        'content' => $question
                    ]
                ],
                'stream' => true,
                'max_tokens' => 2048,
                'temperature' => 0.7,
                'top_p' => 0.7,
                'top_k' => 50,
                'frequency_penalty' => 0.5,
                'n' => 1,
                'response_format' => [
                    'type' => 'text'
                ]
            ];

            // 准备 cURL 请求
            $ch = curl_init($this->url);
            curl_setopt_array($ch, [
                CURLOPT_POST => true,
                CURLOPT_POSTFIELDS => json_encode($data),
                CURLOPT_RETURNTRANSFER => true,
                CURLOPT_HTTPHEADER => [
                    'Content-Type: application/json',
                    'Authorization: Bearer ' . $this->apiKey
                ],
                CURLOPT_WRITEFUNCTION => function($ch, $data) {
                    echo $data;
                    return strlen($data);
                }
            ]);

            try {
                // 发送请求并处理响应
                $handle = curl_exec($ch);
                
                if (curl_errno($ch)) {
                    throw new Exception(curl_error($ch));
                }

                // 添加分隔符
                echo "\n----------------------------------------\n";
                $this->saveToFile("\n----------------------------------------\n");

            } catch (Exception $e) {
                $error_msg = "请求错误: " . $e->getMessage() . "\n";
                echo $error_msg;
                $this->saveToFile($error_msg);
            } finally {
                curl_close($ch);
            }
        }
    }
}

// 运行程序
$chatbot = new DeepSeekChat();
$chatbot->chat();

3. 代码详解

3.1 类结构

DeepSeekChat: 主类，封装所有功能
__construct: 构造函数，初始化日志文件
saveToFile: 保存对话记录
processStreamingResponse: 处理流式响应
chat: 主对话循环

3.2 关键功能

文件操作

private function saveToFile($content, $isQuestion = false) {
    $timestamp = date('Y-m-d H:i:s');
    $text = $isQuestion 
        ? "\n[$timestamp] Question:\n$content\n\n[$timestamp] Answer:\n"
        : $content;
    
    file_put_contents($this->logFile, $text, FILE_APPEND);
}

cURL 配置

curl_setopt_array($ch, [
    CURLOPT_POST => true,
    CURLOPT_POSTFIELDS => json_encode($data),
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_HTTPHEADER => [
        'Content-Type: application/json',
        'Authorization: Bearer ' . $this->apiKey
    ]
]);