一、具体作用
调用其他厂商提供的服务API
二、对应示例
1、get
public static void main(String[] args) {
String result = "";
BufferedReader in = null;
try {
String urlName = url;
URL realUrl = new URL(urlName);
URLConnection conn = realUrl.openConnection();// 打开和URL之间的连接
conn.setRequestProperty("accept", "*/*");// 设置通用的请求属性
conn.setRequestProperty("connection", "Keep-Alive");
conn.setRequestProperty("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)");
conn.setConnectTimeout(4000);
conn.connect();// 建立实际的连接
in = new BufferedReader(new InputStreamReader(conn.getInputStream(), "UTF-8"));// 定义BufferedReader输入流来读取URL的响应
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);
} finally {// 使用finally块来关闭输入流
try {
if (in != null) {
in.close();
}
} catch (IOException ex) {
System.out.println("关闭流异常");
}
}
System.out.println(result);
}
2、post
public static void main(String[] args) {
PrintWriter out = null;
BufferedReader in = null;
String result = "";
try {
URL realUrl = new URL(url);
// 打开和URL之间的连接
URLConnection conn = realUrl.openConnection();
// 设置通用的请求属性
conn.setRequestProperty("accept", "*/*");
conn.setRequestProperty("connection", "Keep-Alive");
conn.setRequestProperty("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
// 发送POST请求必须设置如下两行
conn.setDoOutput(true);
conn.setDoInput(true);
// 获取URLConnection对象对应的输出流
out = new PrintWriter(conn.getOutputStream());
// 发送请求参数
out.print(param);
// flush输出流的缓冲
out.flush();
// 定义BufferedReader输入流来读取URL的响应
in = new BufferedReader(new InputStreamReader(conn.getInputStream()));
String line;
while ((line = in.readLine()) != null) {
result += line;
}
} catch (Exception e) {
System.out.println("[POST请求]向地址:" + url + " 发送数据:" + param + " 发生错误!");
} finally {// 使用finally块来关闭输出流、输入流
try {
if (out != null) {
in.close();
}
if (in != null) {
in.close();
}
} catch (IOException ex) {
System.out.println("关闭流异常");
}
}
System.out.println(result);
}
引用地址:https://www.cnblogs.com/timjames/p/8072517.html