[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();
}