[java,2018-01-16] HttpClient发送、接收 json 请求

最近需要用到许多在后台发送http请求的功能，可能需要发送json和xml类型的数据。

就抽取出来写了一个帮助类：

首先判断发送的数据类型是json还是xml：

import org.dom4j.DocumentException;
import org.dom4j.DocumentHelper;

import com.alibaba.fastjson.JSONException;
import com.alibaba.fastjson.JSONObject;

    /**
     * 判断是否是json结构
     */
    public static boolean isJson(String value) {
        try {
            JSONObject.parseObject(value);
        } catch (JSONException e) {
            return false;
        }
        return true;
    } 

    /**
     * 判断是否是xml结构
     */
    public static boolean isXML(String value) {
        try {
            DocumentHelper.parseText(value);
        } catch (DocumentException e) {
            return false;
        }
        return true;
    }         

判断之后就设置对应的属性，然后执行post方法：

import org.apache.http.HttpResponse;
import org.apache.http.client.config.RequestConfig;
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;

　　 private static int connectionTimeout = 1000;// 连接超时时间,毫秒
    private static int soTimeout = 30000;// 读取数据超时时间，毫秒
    /** HttpClient对象 */
    private static CloseableHttpClient httpclient = HttpClients.
            custom().disableAutomaticRetries().build();
    /*** 超时设置 ****/
    private static RequestConfig requestConfig = RequestConfig.custom()
            .setSocketTimeout(soTimeout)
            .setConnectTimeout(connectionTimeout)
            .build();//设置请求和传输超时时间  

　　/**
     * 根据给定的URL地址和参数字符串，以post方法调用，如果成功返回true，如果失败返回false
     *
     * @param url  String url地址，不含参数
     * @param param   Map<String, Object> 参数字表单
     * @return boolean true－成功，false失败，如果返回成功可以getStrGetResponseBody()
     *         获取返回内容字符串，如果失败，则可访问getErrorInfo()获取错误提示。
     */
    public String executePostMethod(String strURL, String param) {
        System.out.println("step into executePostMethod");
        String strResult = "";
        HttpPost post = new HttpPost(strURL);
        post.setConfig(requestConfig);
        StringEntity entity;

        try {
            System.out.println("step into try");

            if(isJson(param)){
                System.out.println("it is json");
                entity = new StringEntity(param,"utf-8");        // 解决中文乱码问题
                entity.setContentEncoding("UTF-8");
                entity.setContentType("application/json");
                post.setEntity(entity);
            }else if(isXML(param)){
                System.out.println("it is xml");
                entity = new StringEntity(param,"utf-8");        // 解决中文乱码问题
                entity.setContentEncoding("UTF-8");
                entity.setContentType("text/xml");
                post.setEntity(entity);
            }else{
                entity = new StringEntity(param,"utf-8");        // 解决中文乱码问题
                entity.setContentEncoding("UTF-8");
                entity.setContentType("application/x-www-form-urlencoded");
                post.setEntity(entity);
            }

            //发起请求
            HttpResponse httpResponse = httpclient.execute(post);
            // 请求结束，返回结果
            strResult = EntityUtils.toString(httpResponse.getEntity());
            System.out.println(strResult);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return strResult;
    }

另附上map转为xml和json的方法：

import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import java.util.Map.Entry;

import org.dom4j.Document;
import org.dom4j.DocumentHelper;
import org.dom4j.Element;

import com.alibaba.fastjson.JSONObject;

   /**
     * 将map转换为xml
     * @param map
     */
    private static String convertMap2Xml(Map<String,String> map) {
        Set<Entry<String,String>> entrys = map.entrySet();
        Iterator<Entry<String,String>> iter = entrys.iterator();
        Document doc = DocumentHelper.createDocument();
        Element root = DocumentHelper.createElement("xml");
        while(iter.hasNext()) {
            Entry<String,String> entry = iter.next();
            Element key = DocumentHelper.createElement(entry.getKey());
            key.addCDATA(entry.getValue());
            root.add(key);
        }
        doc.add(root);
        return doc.asXML();
    }

　　/**
     * 将map转换为json
     * @param map
     */
    private static String convertMap2Json(Map<String,String> map) {
        JSONObject json = JSONObject.parseObject(map.toString());
                return json.toString();
    }    

http接受json格式的数据

public String getJsonData(HttpServletRequest request) {
    System.out.println(request.getCharacterEncoding());
    BufferedReader br = new BufferedReader(new InputStreamReader(request.getInputStream(),"utf-8"));
    String line = null;
    StringBuilder sb = new StringBuilder();
    while((line = br.readLine())!=null){
         sb.append(line);
    }
    return sb.toString();
}