Java使用HttpClient发送请求的几种常用方式
使用的jar包有3个，Maven中添加以下依赖：
1第一种：普通的Get/Post请求，Get请求可以带参数（无需登陆）
public static String GetHtttpLink(String path) throws Exception {
HttpClient client = new HttpClient();// 打开新窗口
GetMethod get = new GetMethod(path);//path是请求地址，可以带参数
int st1 = client.executeMethod(get);
logger.info("执行状态：" + st1);
String result = get.getResponseBodyAsString();//服务端返回的Response
get.releaseConnection();//释放链接
return result;
}
public static String PostHtttpLink(String path) throws Exception {HttpClient client = new HttpClient();// 打开新窗口
PostMethod po = new PostMethod(path);
int st1 = client.executeMethod(po);
logger.info("执行状态：" + st1);
String result = po.getResponseBodyAsString();//服务端返回的Response
po.releaseConnection();
return result;
}
第二种：带多个参数的Post请求 （无需登陆）
public static String PostWithParas() {
HttpClient client = new HttpClient();
PostMethod postMethod = new PostMethod("http://127.0.0.1:8080/userrz");
NameValuePair param1 = new NameValuePair("id", "XXX");//参数1
NameValuePair param2 = new NameValuePair("time", "XXXXXX");//参数2
NameValuePair param3 = new NameValuePair("url", "XXXXXX");//参数3
NameValuePair param4 = new NameValuePair("msg", "XXX");参数4 postMethod.setRequestBody(new NameValuePair[]{param1, param2, param3, param4 });//设置参数
String result="";
try {
client.executeMethod(postMethod);//执行请求
result = postMethod.getResponseBodyAsString();//获取返回的Response
} catch (IOException e) {
e.printStackTrace();
}
postMethod.releaseConnection();//释放链接
}
第三种：带Cookies请求认证，访问网站内部某个页面（需要登陆，用户名密码认证）
public static String GetLink(String Corpcode, String Code) throws Exception {
HttpClient client = new HttpClient();// 打开新窗口
client.getHostConfiguration().setHost("localhost", 8080);// 配置
// 模拟手动登录页面,login是处理登陆的action
PostMethod post = new PostMethod("/login");
NameValuePair username = new NameValuePair("username", "admin");//用户名
NameValuePair pass = new NameValuePair("password", "admin123");//密码
post.setRequestBody(new NameValuePair[] { username, pass });
int status = client.executeMethod(post);
System.out.println("执行状态:" + status + ",返回状态：" + post.getStatusLine(); post.releaseConnection();
// 查看 cookie，并传递Cookies到服务器认证
CookieSpec cookiespec = CookiePolicy.getDefaultSpec();
Cookie[] cookies = cookiespec.match("localhost", 8080, "/", false, client.getState().getCookies());
if (cookies.length == 0) {
System.out.println("没有Cookies");
} else {
for (int i = 0; i < cookies.length; i++) {
System.out.println("Cookies：" + cookies[i].toString());
}
}
// 因为前面已经登陆了，也加入了Cookies，所以才可以直接访问这个地址
GetMethod get = new GetMethod("/user");//这个才是需要访问的真正action
int stats = client.executeMethod(get);
String result = get.getResponseBodyAsString();
System.out.println("Get请求:" + result);
get.releaseConnection();
return result;
}