本节总结了使用http客户端访问外部接口的用法。 后期发现什么缺陷的话就更改。 欢迎读者指出这种方法的缺点。
首先，创建返回实体。
公共类http result {
//响应的状态代码
私有代码；
//响应的响应体
私有字符串主体；
publichttpresult(intcode，String body ) {
this.code=代码；
this.body=body；
}
省去get/set
}
创建http客户端util :
公共类http客户端实用程序{
privatestaticcloseablehttpclienthttpclient=http clients.create default (； 用静态实现单实例。 如果这里不完整，成为多线程，就会出现问题。
//*
*带参数的get请求
*
* @param url
* @param map
* @return
* @throws Exception
*/
publicstatichttpresultdoget (string URL，Map map ) throws Exception { )。
声明URIBuilder
uribuilderuribuilder=new uri builder (URL；
//判断参数映射是否为非空
if (地图！=null ) {
//导线参数
映射.条目条目：映射. entryset ) }
//设定参数
uri builder.set parameter (entry.getkey )，entry.getValue ) ).toString )；
}
}
创建//2httpget对象相当于设置url请求地址
http get http get=new http get (uri builder.build () )；
利用//3 http客户端进行httpGet，相当于按下回车，开始请求
closeablehttpresponseresponse=http client.execute (http get )；
分析//4结果，封装并返回对象httpResult，相当于显示相应的结果
//状态代码
//response.get statusline (.get status code )；
//响应、字符串、response.getEntity ) )为空时，以下代码将出错，因此在分析之前判断为非空
//entity utils.tostring (response.get entity )，' UTF-8 ' )；
HttpResult httpResult=null；
//分析数据封装HttpResult
if(response.getentity )！=null ) {
http result=newhttpresult (response.get statusline ().getStatusCode )、
entity utils.tostring (response.get entity )，' UTF-8 ' )；
} else {
http result=newhttpresult (response.get statusline ().getStatusCode )，'')；
}
//返回
返回http结果；
}
//*
*无参数的get请求
*
* @param url
* @return
* @throws Exception
*/
publicstatichttpresultdoget (string URL ) throws Exception {
HTPresulthttpresult=doget(URL，null )；
返回http结果；
}
//*
*带参数的开机自检请求
*
* @param url
* @return
* @throws Exception
*/
publicstatichttpresultdopost (str
ing url, Map reqMap, Map headersMap) throws Exception {// 声明httpPost请求
HttpPost httpPost = new HttpPost(url);
for (Map.Entry entry: headersMap.entrySet())
httpPost.addHeader(entry.getKey(), entry.getValue());
// 判断map不为空
if (reqMap != null) {
// 创建form表单对象
StringEntity formEntity = new StringEntity(JSON.toJSONString(reqMap), "UTF-8");
// 把表单对象设置到httpPost中
httpPost.setEntity(formEntity);
}
// 使用HttpClient发起请求，返回response
CloseableHttpResponse response = httpClient.execute(httpPost);
// 解析response封装返回对象httpResult
HttpResult httpResult = null;
if (response.getEntity() != null) {
httpResult = new HttpResult(response.getStatusLine().getStatusCode(),
EntityUtils.toString(response.getEntity(), "UTF-8"));
} else {
httpResult = new HttpResult(response.getStatusLine().getStatusCode(), "");
}
// 返回结果
return httpResult;
}
/**
* 不带参数的post请求
*
* @param url
* @return
* @throws Exception
*/
public static HttpResult doPost(String url) throws Exception {
HttpResult httpResult = doPost(url, null,null);
return httpResult;
}
/**
* 带参数的Put请求
*
* @param url
* @param map
* @return
* @throws Exception
*/
public static HttpResult doPut(String url, Map map) throws Exception {
// 声明httpPost请求
HttpPut httpPut = new HttpPut(url);
// 判断map不为空
if (map != null) {
// 声明存放参数的List集合
List params = new ArrayList();
// 遍历map，设置参数到list中
for (Map.Entry entry : map.entrySet()) {
params.add(new BasicNameValuePair(entry.getKey(), entry.getValue().toString()));
}
// 创建form表单对象
UrlEncodedFormEntity formEntity = new UrlEncodedFormEntity(params, "UTF-8");
// 把表单对象设置到httpPost中
httpPut.setEntity(formEntity);
}
// 使用HttpClient发起请求，返回response
CloseableHttpResponse response = httpClient.execute(httpPut);
// 解析response封装返回对象httpResult
HttpResult httpResult = null;
if (response.getEntity() != null) {
httpResult = new HttpResult(response.getStatusLine().getStatusCode(),
EntityUtils.toString(response.getEntity(), "UTF-8"));
} else {
httpResult = new HttpResult(response.getStatusLine().getStatusCode(), "");
}
// 返回结果
return httpResult;
}
/**
* 带参数的Delete请求
*
* @param url
* @param map
* @return
* @throws Exception
*/
public static HttpResult doDelete(String url, Map map) throws Exception {
// 声明URIBuilder
URIBuilder uriBuilder = new URIBuilder(url);
// 判断参数map是否为非空
if (map != null) {
// 遍历参数
for (Map.Entry entry : map.entrySet()) {
// 设置参数
uriBuilder.setParameter(entry.getKey(), entry.getValue().toString());
}
}
// 2 创建httpGet对象，相当于设置url请求地址
HttpDelete httpDelete = new HttpDelete(uriBuilder.build());
// 3 使用HttpClient执行httpGet，相当于按回车，发起请求
CloseableHttpResponse response = httpClient.execute(httpDelete);
// 4 解析结果，封装返回对象httpResult，相当于显示相应的结果
// 状态码
// response.getStatusLine().getStatusCode();
// 响应体，字符串，如果response.getEntity()为空，下面这个代码会报错,所以解析之前要做非空的判断
// EntityUtils.toString(response.getEntity(), "UTF-8");
HttpResult httpResult = null;
// 解析数据封装HttpResult
if (response.getEntity() != null) {
httpResult = new HttpResult(response.getStatusLine().getStatusCode(),
EntityUtils.toString(response.getEntity(), "UTF-8"));
} else {
httpResult = new HttpResult(response.getStatusLine().getStatusCode(), "");
}
// 返回
return httpResult;
}
/**
* 返回常用请求头
* @return
*/
public static Map commentHeader(){
Map map = new HashMap<>();
map.put("Content-Type", "application/json");
return map;
}
}
测试一下：
package cn.xxxxxx.httpclient.test;
import java.util.HashMap;
import java.util.Map;
import org.junit.Before;
import org.junit.Test;
import cn.itcast.httpclient.APIService;
import cn.itcast.httpclient.HttpResult;
public class APIServiceTest {
// 查询
@Test
public void testGet() throws Exception {
// http://manager.aaaaaa.com/rest/item/interface/{id}
String url = "http://manager.aaaaaa.com/rest/item/interface/42";
HttpResult httpResult = HttpClientUtil.doGet(url);
System.out.println(httpResult.getCode());
System.out.println(httpResult.getBody());
}
// 查询
@Test
public void testPost() throws Exception {
//设置参数
Map reqMap = new HashMap();
reqMap.put("distCode", arsArg.getDistCode());
HttpResult httpResult = null;
try {
//RestUrlsCommons.RMDS_DISTRICT_FINDBYDISTCODE为url
//reqMap：请求参数
//HttpClientUtil.commentHeader()：请求头
httpResult = HttpClientUtil.doPost(RestUrlsCommons.RMDS_DISTRICT_FINDBYDISTCODE, reqMap, HttpClientUtil.commentHeader());
} catch (Exception e) {
e.printStackTrace();
}
System.out.println(httpResult.getCode());
System.out.println(httpResult.getBody());
}
}