方法2：

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;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;
public class Test  {

    public static void main(String[] args) throws IOException {
        InputStreamReader inputStreamReader = null;
BufferedReader reader = null;
String line = null;
//兩個頁面引數
        //據我觀察這個url不變
String backUrl = "http%3A%2F%2Fredmine.tvbanywhere.net%2Fredmine%2F";
String authenticityToken = null;
//建立httpclient物件
CloseableHttpClient httpClient = HttpClients.createDefault();
//get請求訪問這個url是頁面
        //獲取auth_token
HttpGet getParam = new HttpGet("http://redmine.tvbanywhere.net/redmine/login");
CloseableHttpResponse response1 = httpClient.execute(getParam);
InputStream inputStream1 = response1.getEntity().getContent();
inputStreamReader = new InputStreamReader(inputStream1);
reader = new BufferedReader(inputStreamReader);
        while ((line = reader.readLine())!= null){
            if (line.contains("name=\"authenticity_token\"")){
                System.out.println(line);
String sub1 = line.substring(line.indexOf("value=\"") + 7);
authenticityToken = sub1.substring(0, sub1.indexOf("\""));
}
        }
        reader.close();
inputStreamReader.close();
inputStream1.close();
//post 請求是登入操作
HttpPost dologin = new HttpPost("http://redmine.tvbanywhere.net/redmine/login");
List<NameValuePair> list = new ArrayList<NameValuePair>();
list.add(new BasicNameValuePair("authenticity_token",authenticityToken));
list.add(new BasicNameValuePair("back_url",backUrl));
list.add(new BasicNameValuePair("username","[email protected]"));
list.add(new BasicNameValuePair("password","[email protected]"));
UrlEncodedFormEntity urlEncodedFormEntity = null;
urlEncodedFormEntity = new UrlEncodedFormEntity(list);
dologin.setEntity(urlEncodedFormEntity);
CloseableHttpResponse response2 = httpClient.execute(dologin);
HttpGet get1 = new HttpGet("http://redmine.tvbanywhere.net/redmine/search?issues=1&[email protected]");
CloseableHttpResponse response3 = httpClient.execute(get1);
System.err.println("get" + get1.getURI());
InputStream inputStream3 = response3.getEntity().getContent();
inputStreamReader = new InputStreamReader(inputStream3);
reader = new BufferedReader(inputStreamReader);
        while ((line = reader.readLine()) != null){
            System.out.println(line);
}
    }
}