Java application/json post请求 utf-8编码

要使用Java发送带有UTF-8编码的application/json POST请求，可以按照以下步骤进行操作：

1. 导入必要的类和包：

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.nio.charset.StandardCharsets;
import java.util.HashMap;
import java.util.Map;

2. 定义请求参数：

String url = "http://example.com/api/endpoint";
String json = "{\"key1\":\"value1\",\"key2\":\"value2\"}";

3. 设置请求头：

Map<String, String> headers = new HashMap<>();
headers.put("Content-Type", "application/json; charset=UTF-8");

4. 创建连接对象并设置请求方法、请求头和请求体：

URL object = new URL(url);
HttpURLConnection con = (HttpURLConnection) object.openConnection();
con.setDoOutput(true);
con.setDoInput(true);
con.setRequestMethod("POST");
for (String key : headers.keySet()) {
    con.setRequestProperty(key, headers.get(key));
}
byte[] postData = json.getBytes(StandardCharsets.UTF_8);
con.setRequestProperty("Content-Length", String.valueOf(postData.length));
con.getOutputStream().write(postData);

5. 获取响应：

int responseCode = con.getResponseCode();
BufferedReader in = new BufferedReader(new InputStreamReader(con.getInputStream(), StandardCharsets.UTF_8));
String inputLine;
StringBuilder response = new StringBuilder();
while ((inputLine = in.readLine()) != null) {
    response.append(inputLine);
}
in.close();

完整代码如下：

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.nio.charset.StandardCharsets;
import java.util.HashMap;
import java.util.Map;

public class JsonPostRequestExample {
    public static void main(String[] args) throws Exception {
        String url = "http://example.com/api/endpoint";
        String json = "{\"key1\":\"value1\",\"key2\":\"value2\"}";

        Map<String, String> headers = new HashMap<>();
        headers.put("Content-Type", "application/json; charset=UTF-8");

        URL object = new URL(url);
        HttpURLConnection con = (HttpURLConnection) object.openConnection();
        con.setDoOutput(true);
        con.setDoInput(true);
        con.setRequestMethod("POST");
        for (String key : headers.keySet()) {
            con.setRequestProperty(key, headers.get(key));
        }
        byte[] postData = json.getBytes(StandardCharsets.UTF_8);
        con.setRequestProperty("Content-Length", String.valueOf(postData.length));
        con.getOutputStream().write(postData);

        int responseCode = con.getResponseCode();
        BufferedReader in = new BufferedReader(new InputStreamReader(con.getInputStream(), StandardCharsets.UTF_8));
        String inputLine;
        StringBuilder response = new StringBuilder();
        while ((inputLine = in.readLine()) != null) {
            response.append(inputLine);
        }
        in.close();

        System.out.println("Response Code: " + responseCode);
        System.out.println("Response Body: " + response.toString());
    }
}