Java 用HTTP的方式发送JSON报文请求
前言：
项目调用第三方接口时，通常是用socket或者http的通讯方式发送请求：http 为短连接，客户端发送请求都需要服务器端回送响应，请求结束后，主动释放链接。Socket为长连接：通常情况下Socket 连接就是 TCP 连接，因此 Socket 连接一旦建立,通讯双方开始互发数据内容，直到双方断开连接。下面介绍HTTP的方式发送和接收JSON报文。
需求：
用HTTP的方式，向URL为127.0.0.1:8888地址发送json报文，返回的结果也是json报文。
主要代码如下：
String resp= null;
JSONObject obj = new JSONObject();
obj.put("name", "张三");
obj.put("age", "18");
String query = obj.toString();
log.info("发送到URL的报文为：");
log.info(query);
try {
URL url = new URL("http://127.0.0.1:8888"); //url地址
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setDoInput(true);
connection.setDoOutput(true);
connection.setRequestMethod("POST");
connection.setUseCaches(false);
connection.setInstanceFollowRedirects(true);
connection.setRequestProperty("Content-Type","application/json");
connection.connect();
try (OutputStream os = connection.getOutputStream()) {
os.write(query.getBytes("UTF-8"));
}
try (BufferedReader reader = new BufferedReader(
new InputStreamReader(connection.getInputStream()))) {
String lines;
StringBuffer sbf = new StringBuffer();
while ((lines = reader.readLine()) != null) {
lines = new String(lines.getBytes(), "utf-8");
sbf.append(lines);
}
log.info("返回来的报文："+sbf.toString());
resp = sbf.toString();
}
connection.disconnect();
} catch (Exception e) {
e.printStackTrace();
}finally{
JSONObject json = (JSONObject)JSON.parse(resp);
}
网上还有一种拼json发送报文的方式，也把代码分享出来：
String resp = null;
String name = request.getParameter("userName");
String age = request.getParameter("userAge");
String query = "{\"name\":\""+name+"\",\"age\":\""+age+"\"}";
try {
URL url = new URL("http://10.10.10.110:8888"); //url地址
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setDoInput(true);
connection.setDoOutput(true);
connection.setRequestMethod("POST");
connection.setUseCaches(false);
connection.setInstanceFollowRedirects(true);
connection.setRequestProperty("Content-Type","application/json");
connection.connect();
try (OutputStream os = connection.getOutputStream()) {
os.write(query.getBytes("UTF-8"));
}
try (BufferedReader reader = new BufferedReader(
new InputStreamReader(connection.getInputStream()))) {
String lines;
StringBuffer sbf = new StringBuffer();
while ((lines = reader.readLine()) != null) {
lines = new String(lines.getBytes(), "utf-8");
sbf.append(lines);
}
log.info("返回来的报文："+sbf.toString());
resp = sbf.toString();
}
connection.disconnect();
} catch (Exception e) {
e.printStackTrace();
}finally{
JSONObject json = (JSONObject)JSON.parse(resp);
}
两种方式其实都是一样的。