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java如何调用接口

2026-01-14 16:31:18Java

调用接口的基本方法

在Java中调用接口通常涉及实现接口或使用接口引用对象。以下是几种常见场景的示例：

定义接口

public interface MyInterface {
    void doSomething();
}

实现接口

public class MyClass implements MyInterface {
    @Override
    public void doSomething() {
        System.out.println("Doing something...");
    }
}

通过接口引用调用

MyInterface obj = new MyClass();
obj.doSomething();

调用REST API接口

对于HTTP接口调用，常用HttpURLConnection或第三方库如OkHttp/Apache HttpClient：

使用HttpURLConnection

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

int responseCode = conn.getResponseCode();
if (responseCode == 200) {
    BufferedReader in = new BufferedReader(new InputStreamReader(conn.getInputStream()));
    String inputLine;
    StringBuilder response = new StringBuilder();
    while ((inputLine = in.readLine()) != null) {
        response.append(inputLine);
    }
    in.close();
    System.out.println(response.toString());
}

使用Spring RestTemplate

RestTemplate restTemplate = new RestTemplate();
String result = restTemplate.getForObject("https://api.example.com/data", String.class);

调用WebService接口

使用JAX-WS生成客户端代码：

URL wsdlUrl = new URL("http://example.com/service?wsdl");
QName qname = new QName("http://example.com/", "MyService");
Service service = Service.create(wsdlUrl, qname);
MyInterface port = service.getPort(MyInterface.class);
port.doSomething();

异步接口调用

使用CompletableFuture实现异步调用：

CompletableFuture.supplyAsync(() -> {
    // 模拟耗时操作
    try { Thread.sleep(1000); } 
    catch (InterruptedException e) { e.printStackTrace(); }
    return "Result";
}).thenAccept(result -> System.out.println("Got: " + result));