java HTTP响应怎么解析

在 Java 中解析 HTTP 响应，通常取决于你使用的是哪种方式发送请求。下面按常见场景给你说明，并给示例。

一、使用 HttpURLConnection（JDK 原生）

1. 发送请求并获取响应

URL url = new URL("https://example.com/api");
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("GET");

int status = conn.getResponseCode();
BufferedReader reader = new BufferedReader(
        new InputStreamReader(conn.getInputStream(), "UTF-8"));

String line;
StringBuilder response = new StringBuilder();
while ((line = reader.readLine()) != null) {
    response.append(line);
}
reader.close();
conn.disconnect();

System.out.println(response.toString());

2. 解析 JSON 响应（示例）

import com.fasterxml.jackson.databind.ObjectMapper;

ObjectMapper mapper = new ObjectMapper();
Map<String, Object> map = mapper.readValue(response.toString(), Map.class);

二、使用 Apache HttpClient（常用）

1. 发送请求

CloseableHttpClient client = HttpClients.createDefault();
HttpGet get = new HttpGet("https://example.com/api");

CloseableHttpResponse response = client.execute(get);

2. 解析响应内容

HttpEntity entity = response.getEntity();
String result = EntityUtils.toString(entity, "UTF-8");

System.out.println(result);

3. 解析 JSON

ObjectMapper mapper = new ObjectMapper();
MyBean bean = mapper.readValue(result, MyBean.class);

三、使用 Spring RestTemplate

1. 直接解析为对象

RestTemplate restTemplate = new RestTemplate();
MyBean bean = restTemplate.getForObject(
        "https://example.com/api", MyBean.class);

2. 获取原始响应

ResponseEntity<String> response =
        restTemplate.getForEntity(url, String.class);
String body = response.getBody();

四、使用 Java 11+ HttpClient（推荐）

HttpClient client = HttpClient.newHttpClient();
HttpRequest request = HttpRequest.newBuilder()
        .uri(URI.create("https://example.com/api"))
        .build();

HttpResponse<String> response =
        client.send(request, HttpResponse.BodyHandlers.ofString());

System.out.println(response.statusCode());
System.out.println(response.body());

五、常见解析方式总结

六、常见坑

• 状态码 ≠ 200 时，可能要从 getErrorStream() 读错误
• 注意 字符编码
• 大响应避免一次性读入内存

如果你能告诉我：

• 用的是哪种 HTTP 客户端
• 响应是 JSON / XML / 文件
• Java 版本

我可以给你更精确的代码。