（一）get请求
public static String sendGet(String url, String param) {
String result = "";
BufferedReader in = null;
try {
String urlNameString = url + "?" + param;
URL realUrl = new URL(urlNameString);
// 打开和URL之间的连接
URLConnection connection = realUrl.openConnection();
// 设置通用的请求属性
connection.setRequestProperty("accept", "*/*");
connection.setRequestProperty("connection", "Keep-Alive");
connection.setRequestProperty("user-agent",
"Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
// 建立实际的连接
connection.connect();
// 获取所有响应头字段
Map<String, List<String>> map = connection.getHeaderFields();
// 遍历所有的响应头字段
for (String key : map.keySet()) {
System.out.println(key + "--->" + map.get(key));
}
// 定义 BufferedReader输入流来读取URL的响应
in = new BufferedReader(new InputStreamReader(
connection.getInputStream()));
String line;
while ((line = in.readLine()) != null) {
result += line;
}
} catch (Exception e) {
System.out.println("发送GET请求出现异常！" + e);
e.printStackTrace();
}
// 使用finally块来关闭输入流
finally {
try {
if (in != null) {
in.close();
}
} catch (Exception e2) {
e2.printStackTrace();
}
}
return result;
}
测试代码如下：
public static void main(String[] args) {
System.out.println("图灵");
String url = "http://www.tuling123.com/openapi/api";
String param = "key=69a51fe6b4ec4c57b453a464dba1429b&info=你好";
// categoryId=类别主键contentId=文章主键
String source = HttpRequest.sendGet(url, param);
System.out.println(source);
}
测试结果如下：
图灵
Transfer-Encoding--->[chunked]
null--->[HTTP/1.1 200 OK]
Access-Control-Allow-Origin--->[*]
Connection--->[keep-alive]
Date--->[Fri, 02 Feb 2018 06:06:19 GMT]
Content-Type--->[text/json; charset=UTF-8]
{"code":100000,"text":"嗯…又见面了。"}
post
{"code":40007,"text":"您的请求内容为空。"}
（二）post请求
1.post请求方式（参数直接添加在url后面）
public String post(String urlString) throws Exception{
String res = "";
try {
URL url = new URL(urlString);
java.net.HttpURLConnection conn = (java.net.HttpURLConnection) url.openConnection();
conn.setDoOutput(true);
conn.setRequestMethod("POST");
java.io.BufferedReader in = new java.io.BufferedReader(
new java.io.InputStreamReader(conn.getInputStream(),"UTF-8"));
String line;
while ((line = in.readLine()) != null) {
res += line + "\n";
}
in.close();
} catch (Exception e) {
System.out.println("error in wapaction,and e is " + e.getMessage());
}
return res;
}
测试代码：
public static String getAddr(double lat, double log) {
// type (100代表道路，010代表POI，001代表门址，111可以同时显示前三项)
String urlString = "http://gc.ditu.aliyun.com/regeocoding?l=" + lat+ "," + log + "&type=010";
return post(urlString);
}
public static void main(String[] args) {
String str = getAddr(22.62, 114.07);
System.out.println(str);
}
测试结果：
{"queryLocation":[22.62,114.07],"addrList":[{"type":"poi","status":1,"name":"揽月居","id":"ANB02F38QUUM","admCode":"440307","admName":"广东省,深圳市,龙岗区,","addr":"坂田雅园路","nearestPoint":[114.07006,22.61863],"distance":137.131}]}
总结：参数直接添加在url后面实际上是把参数放在body里面，服务端接收到请求后通过request.getParameter()方式获取参数值。
2 在学习ajax的时候，如果用post请求，需要设置如下代码。
ajax.setRequestHeader("content-type","application/x-www-form-urlencoded");2.1 Form表单语法
在Form元素的语法中，EncType表明提交数据的格式 用 Enctype 属性指定将数据回发到服务器时浏览器使用的编码类型。 例如： application/x-www-form-urlencoded： 窗体数据被编码为名称/值对。这是标准的编码格式。 multipart/form-data： 窗体数据被编码为一条消息，页上的每个控件对应消息中的一个部分，这个一般文件上传时用。 text/plain： 窗体数据以纯文本形式进行编码，其中不含任何控件或格式字符。
2.2 常用的编码方式
form的enctype属性为编码方式，常用有两种：application/x-www-form-urlencoded和multipart/form-data，默认为application/x-www-form-urlencoded。
1.x-www-form-urlencoded
当action为get时候，浏览器用x-www-form-urlencoded的编码方式把form数据转换成一个字串（name1=value1&name2=value2…），然后把这个字串append到url后面，用?分割，加载这个新的url。
2.multipart/form-data
当action为post时候，浏览器把form数据封装到http body中，然后发送到server。 如果没有type=file的控件，用默认的application/x-www-form-urlencoded就可以了。 但是如果有type=file的话，就要用到multipart/form-data了。浏览器会把整个表单以控件为单位分割，并为每个部分加上Content-Disposition(form-data或者file),Content-Type(默认为text/plain),name(控件name)等信息，并加上分割符(boundary)。
2.3 实体内容body中以form-data方式传参
public static String post(String url, Map<String, String> param, String charset) throws Exception {
CloseableHttpClient httpClient = HttpClients.createDefault();
RequestConfig requestConfig = RequestConfig.custom()
.setConnectTimeout(CONNECT_TIMEOUT).setSocketTimeout(SOCKET_TIMEOUT).build();
CloseableHttpResponse httpResponse = null;
try {
HttpPost post = new HttpPost(url);
post.setConfig(requestConfig);
//创建参数列表
List<NameValuePair> list = new ArrayList<NameValuePair>();
Iterator<Entry<String, String>> it = param.entrySet().iterator();
while(it.hasNext()){
Entry<String, String> entry = it.next();
list.add(new BasicNameValuePair(entry.getKey(), entry.getValue()));
}
//url格式编码
UrlEncodedFormEntity uefEntity = new UrlEncodedFormEntity(list,charset);
post.setEntity(uefEntity);
//执行请求
httpResponse = httpClient.execute(post);
HttpEntity entity = httpResponse.getEntity();
String reStr = EntityUtils.toString(entity);
logger.info("接口返回[{}]:{}",url,reStr);
int statusCode = httpResponse.getStatusLine().getStatusCode();
logger.info("接口状态[{}]:{}",url,statusCode);
if (null != entity && statusCode == HttpURLConnection.HTTP_OK) {
return reStr;
}
} catch (Exception e) {
logger.error("接口异常[{}]:{}", url, e.getMessage());
throw e;
//处理后抛出
} finally {
close(httpResponse,httpClient);
}
return null;
}
测试代码：
public static void main(String[] args) throws Exception {
String url = "http://localhost:18084/apply/checkBaiRongRiskList";
Map<String,String> map = new HashMap<String,String>();
map.put("userName", "checkbr001");
map.put("passWord", "DFrisk0126");
map.put("creditId", "441522198910060016");
map.put("phoneNum", "13066850456");
map.put("name", "李静波");
String post = HttpRequestUtil.post(url, map, "utf-8");
System.out.println(post);
}
测试结果：
{
"data": {
"sequence": "1517215476256004",
"userName": "checkbr001",
"creditId": "441522198910060016",
"phoneNum": "13066850456",
"name": "李静波",
"visitTime": "Fri Feb 02 16:10:49 CST 2018",
"externalDataResult": {
"msg": "百融风险名单DFY8020_BRRL调用成功!",
"als_m3_id_nbank_allnum": "1",
"code": "100",
"als_m3_cell_nbank_allnum": "1"
}
},
"status": 1
}
总结：
参数以表单形式提交用map接收，请求返回String字符串；服务端通过SpringMVC框架用map的key作形参获取参数值；服务端代码如下：
@PostMapping(value = "checkBaiRongRiskList")
public JSONObject checkBaiRongRiskList( String userName, String passWord, String creditId, String phoneNum, String name) {
try {
BairongData result = accessToauditService.checkBaiRongBlackList(userName,passWord,creditId,phoneNum,name);
return Result.ok(result);
} catch (Exception e) {
return Result.fail(e.getStackTrace());
}
}
2.4 实体内容中以x-www-form-data形式传参
同上。
总结：x-www-form-data和form-data两种方式都是以表单形式提交，区别在于form-data可以提交File而x-www-form-data只能提交文本。
2.5 实体内容以raw形式传参
public static String postJson(String uri,String param,String charset) {
try {
logger.info("请求信息uri[" + uri + "], 入参[" + param + "]");
HttpClient httpClient = HttpClients.createDefault();
RequestConfig requestConfig = RequestConfig.custom()
.setConnectTimeout(CONNECT_TIMEOUT).setSocketTimeout(SOCKET_TIMEOUT).build();
HttpPost method = new HttpPost(uri);
method.setConfig(requestConfig);
method.addHeader("Content-type","application/json; charset="+charset);
method.setHeader("Accept", "application/json");
method.setEntity(new StringEntity(param, Charset.forName(charset)));
HttpResponse response = httpClient.execute(method);
int statusCode = response.getStatusLine().getStatusCode();
logger.info("请求返回状态码:"+statusCode);
if (statusCode == HttpStatus.SC_OK) {
return EntityUtils.toString(response.getEntity());
}
} catch (Exception e) {
logger.error("请求异常:"+e.getMessage());
}
return null;
}
测试代码：
public static void main(String[] args) throws Exception {
String url = "http://10.34.2.63:18084/apply/checkBaiRong";
String json = "{\"userName\":\"root\",\r\n" +
" \"passWord\":\"root\",\r\n" +
" \"creditId\":\"522601199510176844\",\r\n" +
" \"phoneNum\":\"15186811540\",\r\n" +
" \"name\":\"吴寿美\"}";
String post = HttpRequestUtil.postJson(url, json, "UTF-8");
System.out.println(post);
}
测试结果：
{"data":"{\"creditId\":\"522601199510176844\",\"name\":\"吴寿美\",\"phoneNum\":\"15186811540\",\"sequence\":\"1517715380644003\",\"userName\":\"root\",\"visitTime\":\"Sun Feb 04 13:57:55 CST 2018\"}","status":1}
服务端代码：
@RequestMapping(value="checkBaiRong",method=RequestMethod.POST,consumes="application/json")
public JSONObject checkBaiRong(@RequestBody CusUser cusUser) {
try {
String result = accessToauditService.checkBaiRong(cusUser);
return Result.ok(result);
} catch (Exception e) {
return Result.fail(e);
}
}
总结：postman发送json格式数据采用raw方式。