HttpClients下载与入门 – 元素领域(zxar520.com)

发表评论
1,313

A+

所属分类：Web技巧

Http协议的重要性相信不用我多说了，HttpClient相比传统JDK自带的URLConnection，增加了易用性和灵活性（具体区别，日后我们再讨论），它不仅是客户端发送Http请求变得容易，而且也方便了开发人员测试接口（基于Http协议的），即提高了开发的效率，也方便提高代码的健壮性。因此熟练掌握HttpClient是很重要的必修内容，掌握HttpClient后，相信对于Http协议的了解会更加深入。

你可以从官方获取最新版本：http://hc.apache.org/index.html。也可以从这里获取官方使用入门示例。
以下示例，输出所有头内容，和页面返回的内容。

import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;
import org.apache.http.Header;
import org.apache.http.HttpEntity;
import org.apache.http.NameValuePair;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.message.BasicNameValuePair;
public class QuickStart {
 public static void main(String[] args) {
  try {
   CloseableHttpClient httpclient = HttpClients.createDefault();
   HttpGet httpGet = new HttpGet("http://zxar520.com");
   CloseableHttpResponse response1 = httpclient.execute(httpGet);
   try {
       System.out.println(response1.getStatusLine()); // 读取状态信息
        
       Header[] hd = response1.getAllHeaders(); // 所有头信息
       for(Header h : hd){
        System.out.println(h.getName() + "：" + h.getValue());
       }
        
       HttpEntity entity1 = response1.getEntity();
       System.out.println(EntityUtils.toString(entity1));
   } finally {
       response1.close();
   }
   HttpPost httpPost = new HttpPost("http://zxar520.com");
   List <NameValuePair> paras = new ArrayList <NameValuePair>(); // 设置表单参数
   paras.add(new BasicNameValuePair("username", "name"));
   paras.add(new BasicNameValuePair("password", "pass"));
   httpPost.setEntity(new UrlEncodedFormEntity(paras));
   CloseableHttpResponse response2 = httpclient.execute(httpPost);
   try {
    System.out.println(response1.getStatusLine()); // 读取状态信息
        
       Header[] hd = response1.getAllHeaders(); // 所有头信息
       for(Header h : hd){
        System.out.println(h.getName() + "：" + h.getValue());
       }
        
       HttpEntity entity1 = response1.getEntity();
       System.out.println(EntityUtils.toString(entity1));
   } finally {
       response2.close();
   }
  } catch (Exception e) {
   e.printStackTrace();
  }
 }
  
 /**
  * 读取流
  */
 public static byte[] readStream(InputStream inStream) throws Exception {
  ByteArrayOutputStream outSteam = new ByteArrayOutputStream();
  byte[] buffer = new byte[1024];
  int len = -1;
  while ((len = inStream.read(buffer)) != -1) {
   outSteam.write(buffer, 0, len);
  }
  outSteam.close();
  inStream.close();
  return outSteam.toByteArray();
 }
} 
// 结束

import java.io.ByteArrayOutputStream;

import java.io.InputStream;

import java.util.ArrayList;

import java.util.List;

import org.apache.http.Header;

import org.apache.http.HttpEntity;

import org.apache.http.NameValuePair;

import org.apache.http.client.entity.UrlEncodedFormEntity;

import org.apache.http.client.methods.CloseableHttpResponse;

import org.apache.http.client.methods.HttpGet;

import org.apache.http.client.methods.HttpPost;

import org.apache.http.impl.client.CloseableHttpClient;

import org.apache.http.impl.client.HttpClients;

import org.apache.http.message.BasicNameValuePair;

public class QuickStart {

public static void main(String[] args) {

try {

CloseableHttpClient httpclient = HttpClients.createDefault();

HttpGet httpGet = new HttpGet("http://zxar520.com");

CloseableHttpResponse response1 = httpclient.execute(httpGet);

try {

System.out.println(response1.getStatusLine()); // 读取状态信息

Header[] hd = response1.getAllHeaders(); // 所有头信息

for(Header h : hd){

System.out.println(h.getName() + "：" + h.getValue());

}

HttpEntity entity1 = response1.getEntity();

System.out.println(EntityUtils.toString(entity1));

} finally {

response1.close();

}

HttpPost httpPost = new HttpPost("http://zxar520.com");

List <NameValuePair> paras = new ArrayList <NameValuePair>(); // 设置表单参数

paras.add(new BasicNameValuePair("username", "name"));

paras.add(new BasicNameValuePair("password", "pass"));

httpPost.setEntity(new UrlEncodedFormEntity(paras));

CloseableHttpResponse response2 = httpclient.execute(httpPost);

try {

System.out.println(response1.getStatusLine()); // 读取状态信息

Header[] hd = response1.getAllHeaders(); // 所有头信息

for(Header h : hd){

System.out.println(h.getName() + "：" + h.getValue());

}

HttpEntity entity1 = response1.getEntity();

System.out.println(EntityUtils.toString(entity1));

} finally {

response2.close();

}

} catch (Exception e) {

e.printStackTrace();

}

/**

* 读取流

public static byte[] readStream(InputStream inStream) throws Exception {

ByteArrayOutputStream outSteam = new ByteArrayOutputStream();

byte[] buffer = new byte[1024];

int len = -1;

while ((len = inStream.read(buffer)) != -1) {

outSteam.write(buffer, 0, len);

}

outSteam.close();

inStream.close();

return outSteam.toByteArray();

}

// 结束

GET和POST请求都输出了获取到的服务器内容，POST请求设置了请求的表单参数。

发表评论取消回复

登录 找回密码

登录找回密码