PHP中高效解析API JSON数据并提取特定信息

<?php
// 定义API端点URL
$api_url = 'https://www.lbank.site/request/tick?symbol=alts';

// 使用file_get_contents获取API响应内容
$content = file_get_contents($api_url);

// 检查是否成功获取内容
if ($content === FALSE) {
    die('无法从API获取数据。请检查URL或网络连接。');
}

echo "原始API响应内容：\n";
echo $content;
?>

<?php
// 假设 $content 已经包含了API的JSON响应字符串
// $content = '{"data":[{"symbol":"4jnet/usdt","c":{"price":"0.000000011816"}},{"symbol":"doe/usdt","c":{"price":"0.0606"}}]}'; // 示例JSON结构

$jsontoobject = json_decode($content);

// 检查JSON解析是否成功
if (json_last_error() !== JSON_ERROR_NONE) {
    die('JSON解析失败: ' . json_last_error_msg());
}

echo "\n解析后的PHP对象结构：\n";
print_r($jsontoobject);
?>

<?php
// 假设 $jsontoobject 已经包含了API解析后的PHP对象
// $jsontoobject = json_decode('{"data":[{"symbol":"4jnet/usdt","vol":"5078919159375.1975","amount":"58729.3647","c":{"price":"0.000000011816","usd":"0.00","cny":"0.00"},"toCny":"6.36","change":"-5.98","h":{"price":"0.000000015042","usd":"0.00","cny":"0.00"},"l":{"price":"0.000000010099","usd":"0.00","cny":"0.00"},"dir":"buy","toUsd":"1.00","platform":"LBANK","timestamp":1639627875492},{"symbol":"doe/usdt","vol":"6164668.8295","amount":"323916.8607","c":{"price":"0.0606","usd":"0.06060","cny":"0.38589"},"toCny":"6.36790","change":"33.48","h":{"price":"0.0625","usd":"0.06250","cny":"0.39799"},"l":{"price":"0.0433","usd":"0.04330","cny":"0.27573"},"dir":"buy","toUsd":"1.00000","platform":"LBANK","timestamp":1639627874171}]}'); // 示例解析后的对象

$target_symbol = '4jnet/usdt';
$result_object = null;

// 遍历 $jsontoobject->data 数组中的每个对象
if (isset($jsontoobject->data) && is_array($jsontoobject->data)) {
    foreach ($jsontoobject->data as $item_object) {
        // 检查当前对象的 'symbol' 属性是否与目标匹配
        if (isset($item_object->symbol) && $item_object->symbol === $target_symbol) {
            $result_object = $item_object;
            break; // 找到目标后即可停止遍历
        }
    }
}

// 检查是否找到了目标对象
if ($result_object) {
    echo "\n找到的目标对象：\n";
    print_r($result_object);

    // 访问并打印特定字段，例如 'c' 对象中的 'price'
    if (isset($result_object->c->price)) {
        $price = $result_object->c->price;
        echo "\n{$target_symbol} 的当前价格是: " . $price . "\n";
    } else {
        echo "\n未找到 {$target_symbol} 的价格信息。\n";
    }
} else {
    echo "\n未找到符号为 '{$target_symbol}' 的数据。\n";
}
?>

<?php
// 1. 定义API端点URL和目标符号
$api_url = 'https://www.lbank.site/request/tick?symbol=alts';
$target_symbol = '4jnet/usdt';

// 2. 从API获取原始JSON内容
$content = file_get_contents($api_url);

// 错误处理：检查是否成功获取内容
if ($content === FALSE) {
    die('错误：无法从API获取数据。请检查URL或网络连接。');
}

// 3. 将JSON字符串解析为PHP对象
$jsontoobject = json_decode($content);

// 错误处理：检查JSON解析是否成功
if (json_last_error() !== JSON_ERROR_NONE) {
    die('错误：JSON解析失败。原因：' . json_last_error_msg());
}

$result_object = null;

// 4. 遍历解析后的数据，查找目标符号
// 假设API返回的JSON结构是 {"data": [...]}
if (isset($jsontoobject->data) && is_array($jsontoobject->data)) {
    foreach ($jsontoobject->data as $item_object) {
        // 确保 symbol 属性存在且匹配
        if (isset($item_object->symbol) && $item_object->symbol === $target_symbol) {
            $result_object = $item_object;
            break; // 找到后立即停止遍历
        }
    }
} else {
    die('错误：API响应数据结构不符合预期，未找到 "data" 数组。');
}


// 5. 提取并输出目标信息
if ($result_object) {
    // 检查并访问嵌套的价格信息
    if (isset($result_object->c->price)) {
        $price = $result_object->c->price;
        echo "{$target_symbol} 的当前价格是: " . $price . "\n";
    } else {
        echo "未找到 {$target_symbol} 的价格信息（c.price字段缺失）。\n";
    }
} else {
    echo "未找到符号为 '{$target_symbol}' 的数据。\n";
}

?>