帮我用java和org.apache.http.client.methods.HttpPost写一个发送表单的工具，要求参数是String httpUrl 和Map<String,Object> formData Map<String, String> httpHeader

好的，这里是一个示例代码，可以发送带有表单数据的 POST 请求：

import org.apache.http.NameValuePair;
import org.apache.http.client.entity.UrlEncodedFormEntity;
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.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

public class HttpFormSender {
    public static String sendPost(String httpUrl, Map<String,Object> formData, Map<String, String> httpHeader) throws IOException {
        CloseableHttpClient httpClient = HttpClients.createDefault();
        HttpPost httpPost = new HttpPost(httpUrl);

        // 设置请求头
        for (String key : httpHeader.keySet()) {
            httpPost.setHeader(key, httpHeader.get(key));
        }

        // 设置表单数据
        List<NameValuePair> formParams = new ArrayList<>();
        for (String key : formData.keySet()) {
            formParams.add(new BasicNameValuePair(key, formData.get(key).toString()));
        }
        UrlEncodedFormEntity entity = new UrlEncodedFormEntity(formParams, "UTF-8");
        httpPost.setEntity(entity);

        CloseableHttpResponse response = httpClient.execute(httpPost);
        String result = EntityUtils.toString(response.getEntity());
        response.close();
        httpClient.close();
        return result;
    }
}

使用示例：

import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

public class Main {
    public static void main(String[] args) {
        String httpUrl = "http://example.com/api";
        Map<String,Object> formData = new HashMap<>();
        formData.put("name", "张三");
        formData.put("age", 18);
        Map<String, String> httpHeader = new HashMap<>();
        httpHeader.put("Content-Type", "application/x-www-form-urlencoded");

        try {
            String response = HttpFormSender.sendPost(httpUrl, formData, httpHeader);
            System.out.println(response);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

这个示例代码使用了 Apache HttpComponents 的 HttpClient 来发送请求。你需要先在项目中引入以下 Maven 依赖：

<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpclient</artifactId>
    <version>4.5.13</version>
</dependency>