从java类调用servlet

从java类调用servlet,java,servlets,Java,Servlets,我在一个简单java类中调用servlet进行测试时遇到了一个问题。我想在servlet中传递一个参数,然后该方法将被POST。如何实现这一目标 在搜索答案时,我看到有人推荐了HTTPClient。但我只是想知道是否有办法避免这种情况 您所要做的就是请求一个URL。将所有的名称、值对放在您通常拥有的位置,并在其上打开一个流 下面是示例代码: import java.io.*; import javax.servlet.http.*; import javax.servlet.*; publ

我在一个简单java类中调用servlet进行测试时遇到了一个问题。我想在servlet中传递一个参数,然后该方法将被POST。如何实现这一目标


在搜索答案时,我看到有人推荐了HTTPClient。但我只是想知道是否有办法避免这种情况

您所要做的就是请求一个URL。将所有的名称、值对放在您通常拥有的位置,并在其上打开一个流

下面是示例代码:

import java.io.*; 
import javax.servlet.http.*; 
import javax.servlet.*;

public class SpecialServlet extends HttpServlet 
{

public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException
{ 
    PrintWriter out = res.getWriter(); 
    out.println ("Hello " + req.getParameter("name") + ", this is SpecialServlet!"); 
    out.close(); 
}
} 
java程序:

import java.net.*; 
import java.io.*; 

public class CmdLineApplication
{
public static void main (String args[])
{
String line;
try
{
URL url = new URL( "http://127.0.0.1/servlet/special?name=CmdLineApplication" );
BufferedReader in = new BufferedReader(new InputStreamReader(url.openStream()));
line = in.readLine();
System.out.println( line );
in.close();
}
catch (Exception e)
{
e.printStackTrace();
}
}
}
将servlet.class文件放在servlet引擎的WEB-INF/classes目录中。以常规方式在命令行上运行另一个类:

java CmdLineApplication

您应该看到servlet中的字符串,servlet容器负责初始化和调用servlet。不能直接调用servlet类

要发布请求,可以使用HttpClient

或者你可以使用


使用以下代码。使用此代码还可以维护会话

package webapp;
import org.apache.http.client.HttpClient;
import org.apache.http.impl.client.DefaultHttpClient;


public class HttpClientSingleton {
    public static HttpClientSingleton mSingleton = null;

    public static HttpClient mHttpClient = null;

    //constructor
    private HttpClientSingleton(){
    mHttpClient = new DefaultHttpClient();
    }

    public static HttpClientSingleton getInstance(){
    if( mSingleton == null ){
        mSingleton = new HttpClientSingleton();
    }
    return mSingleton;
    }



}

jsp file:

<%
try{
    int i=0;
String sid = "ED6379C8FDDB801EB970BBDE55E5732D"; 
HttpClientSingleton h1 = HttpClientSingleton.getInstance();
HttpClient client= h1.mHttpClient;


HttpPost responses = new HttpPost("http://localhost:8080/docinbangalore/Billing_address_display?sid="+sid+"");
try {

    HttpResponse respons = client.execute(responses);
    BufferedReader rd = new BufferedReader(new InputStreamReader(respons.getEntity().getContent()));
    String line = "";
    out.println(line = rd.readLine());
    while ((line = rd.readLine()) != null) {
     out.println(line);

    }
  } catch (IOException e) {
    e.printStackTrace();
  }}
catch(Exception e)
{
    out.println(e);
}

%>

您想要/需要模拟使用Java类的POST调用向服务器发送请求的过程吗?