java写postman

Postman是一个流行的API开发工具，它允许用户创建、测试和分享HTTP请求。在Java环境中，虽然Postman本身不是一个编程库，但是你可以通过编程的方式模拟POST等HTTP请求。以下是一个简单的示例，展示如何使用Java的HttpURLConnection或者第三方库如Apache HttpClient来发送POST请求：

**使用HttpURLConnection (基础版)：**

import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;

public void sendPostRequest(String url, String requestBody) {
    try {
        URL obj = new URL(url);
        HttpURLConnection con = (HttpURLConnection) obj.openConnection();
        con.setRequestMethod("POST");
        con.setRequestProperty("Content-Type", "application/json; charset=UTF-8");

        // 发送请求体
        OutputStream os = con.getOutputStream();
        byte[] requestBytes = requestBody.getBytes("UTF-8");
        os.write(requestBytes);
        os.flush();
        os.close();

        int responseCode = con.getResponseCode();
        System.out.println("Response Code : " + responseCode);

        if (responseCode == HttpURLConnection.HTTP_OK) {
            // Read the response
            BufferedReader in = new BufferedReader(new InputStreamReader(con.getInputStream()));
            String inputLine;
            StringBuffer response = new StringBuffer();

            while ((inputLine = in.readLine()) != null) {
                response.append(inputLine);
            }
            in.close();
            System.out.println(response.toString());
        } else {
            throw new RuntimeException("Failed : HTTP error code : " + responseCode);
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
}

**使用Apache HttpClient (高级版):**

import org.apache.http.HttpEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;

public void sendPostRequestWithHttpClient(String url, String requestBody) {
    try (CloseableHttpClient httpClient = HttpClients.createDefault();
         HttpPost httpPost = new HttpPost(url)) {

        httpPost.setHeader("Content-type", "application/json");
        httpPost.setEntity(new StringEntity(requestBody));

        CloseableHttpResponse response = httpClient.execute(httpPost);
        HttpEntity entity = response.getEntity();

        // Check for errors and read the response
        if (entity != null) {
            System.out.println(entity.getContent().toString());
        } else {
            System.out.println("No content received.");
        }

        response.close();
    } catch (Exception e) {
        e.printStackTrace();
    }
}