java httpclient get请求

Java HttpClient是一个用于发送HTTP请求的工具，可以发送GET请求、POST请求等等。其中，GET请求是一种请求方法，用于获取服务器上的资源或数据。通过Java HttpClient发送GET请求，可以让Java程序模拟浏览器发送HTTP请求，获取服务器上的数据信息。

相关问题

java HttpClient get请求返回值输出JSON

可以使用HttpClient发送GET请求获取JSON数据，并将其输出到控制台。以下是一个示例代码：

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.URI;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.util.EntityUtils;
import org.json.JSONObject;

public class HttpClientExample {

    public static void main(String[] args) throws Exception {

        HttpClient client = HttpClientBuilder.create().build();
        HttpGet request = new HttpGet();
        request.setURI(new URI("https://jsonplaceholder.typicode.com/todos/1"));

        HttpResponse response = client.execute(request);

        BufferedReader in = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));

        StringBuilder result = new StringBuilder();
        String line;
        while ((line = in.readLine()) != null) {
            result.append(line);
        }

        JSONObject jsonObject = new JSONObject(result.toString());
        System.out.println(jsonObject.toString());

        EntityUtils.consume(response.getEntity());

    }

}

此代码将向`https://jsonplaceholder.typicode.com/todos/1`发送GET请求，并将返回的JSON数据输出到控制台。请注意，我们创建了一个`HttpClient`实例并使用它来执行请求。在响应中，我们读取实体内容并将其转换为字符串。然后，我们将字符串转换为`JSONObject`并将其输出到控制台。最后，我们将实体内容消耗掉，以便可以重复使用连接。

java httpclient发送请求

Java HttpClient是一个发送HTTP请求的开源库，可以用来发送GET、POST等请求。下面是使用HttpClient发送POST请求的示例代码：

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;
import org.apache.http.util.EntityUtils;

public class HttpClientExample {
    public static void main(String[] args) {
        CloseableHttpClient httpClient = HttpClients.createDefault();
        try {
            HttpPost httpPost = new HttpPost("http://example.com/api/endpoint");
            httpPost.addHeader("Content-Type", "application/json");
            
            String jsonData = "{\"key1\":\"value1\", \"key2\":\"value2\"}";
            StringEntity entity = new StringEntity(jsonData);
            httpPost.setEntity(entity);
            
            CloseableHttpResponse response = httpClient.execute(httpPost);
            try {
                HttpEntity responseEntity = response.getEntity();
                String responseBody = EntityUtils.toString(responseEntity);
                System.out.println(responseBody);
            } finally {
                response.close();
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                httpClient.close();
            } catch (Exception e) {
                e.printStackTrace();            }
        }
    }
}

以上代码使用了Apache HttpClient库，它需要引入相关的jar包。首先创建一个CloseableHttpClient对象，然后创建一个HttpPost对象，并设置请求URL和请求头部信息。接着创建一个StringEntity对象，将请求参数转化为JSON格式，并将其设置为HttpPost的实体。最后执行HttpPost请求，获取响应实体，将其转化为字符串并打印出来。最后关闭HttpClient。