jetty嵌入式Httpserver

alonli

　　我们经常会用程序提供对外的http服务，如 REST 风格的 API 提供给其他的客户来调用我们的服务或者进行一些信息的查询。我们会将这些程序写成WEB程序，提供这样的REST服务。我这里介绍用jetty（一个高性能的Servlet服务器，纯Java编写）编写一个嵌入式的HttpServer。例子的内容很简单，只是提供一些提示。
　　代码如下：

package test;
import org.eclipse.jetty.server.Request;
import org.eclipse.jetty.server.Server;
import org.eclipse.jetty.server.handler.AbstractHandler;
import org.eclipse.jetty.server.handler.ContextHandler;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* <pre>
* JettyExampleServer.java
* @author kanpiaoxue<br>
* @version 1.0
* Create Time 2014年8月28日 下午4:05:25<br>
* Description : 利用Jetty实现简单的嵌入式Httpserver
* </pre>
*/
public class JettyExampleServer {
private static final Logger LOGGER = LoggerFactory
.getLogger(JettyExampleServer.class);
/**
* <pre>
* @param args
* </pre>
*/
public static void main(String[] args) {
try {
// 进行服务器配置
Server server = new Server(8080);
LOGGER.info("server start.");
ContextHandler context = new ContextHandler();
// 设置搜索的URL地址
context.setContextPath("/search");
context.setResourceBase(".");
context.setClassLoader(Thread.currentThread()
.getContextClassLoader());
server.setHandler(context);
context.setHandler(new HelloHandler());
// 启动服务器
server.start();
server.join();
} catch (Exception e) {
e.printStackTrace();
}
}
}
class HelloHandler extends AbstractHandler {
private static final Logger LOGGER = LoggerFactory
.getLogger(JettyExampleServer.class);
@Override
public void handle(String target, Request baseRequest,
HttpServletRequest request, HttpServletResponse response)
throws IOException, ServletException {
/**
* <pre>
* 从 URL 里面得到传递过来的参数：
*  http://localhost:8080/search?query=hello
* 如果你需要传递更多的参数，可以这么写：
*  http://localhost:8080/search?query=hello&name=ZhangLili
* 从这里开始，你可以写自己的代码逻辑。
*
* [注意：GET方法的请求，URL 的最大长度是 1024个字节]
* </pre>
*/
String query = request.getParameter("query");
// String name = request.getParameter("name");
LOGGER.info(String.format("receive query: %s", query));
String result = "welcome to my server.";
if (null != query && query.equals("hello")) {
result = query + ", " + result;
}
LOGGER.info(String.format("response is: %s", result));
// 将服务器处理后的结果返回给调用URL的客户端
print(baseRequest, response, result);
}
/**
* <pre>
* @param baseRequest
* @param response
* @param result 需要返回给客户的结果
* @throws IOException
* 将结果 result 返回给客户
* </pre>
*/
private void print(Request baseRequest, HttpServletResponse response,
String result) throws IOException {
response.setContentType("text/json;charset=utf-8");
response.setStatus(HttpServletResponse.SC_OK);
baseRequest.setHandled(true);
response.getWriter().println(result);
}
}

　　它需要的jar请看附件。附件中有完整的代码，下载之后将lib目录的jar都放在classpath下面，该程序就可以运行。访问地址，如：http://localhost:8080/search?query=hello
　　============================
　　下面的例子是用jetty嵌入式server实现HttpServlet的例子。可以进行GET和POST请求

package test;
import org.eclipse.jetty.server.Server;
import org.eclipse.jetty.servlet.ServletContextHandler;
import org.eclipse.jetty.servlet.ServletHolder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import test.servlet.SearchServlet;
/**
* <pre>
* JettyServletExampleServer.java
* @author kanpiaoxue<br>
* @version 1.0
* Create Time 2014年9月2日 下午4:53:49<br>
* Description : 利用Jetty实现简单的嵌入式Httpserver，利用HttpServlet进行编程
* </pre>
*/
public class JettyServletExampleServer {
private static final Logger LOGGER = LoggerFactory
.getLogger(JettyServletExampleServer.class);
/**
* <pre>
* @param args
* </pre>
*/
public static void main(String[] args) {
try {
Server server = new Server(8080);
ServletContextHandler context = new ServletContextHandler(
ServletContextHandler.SESSIONS);
context.setContextPath("/");
server.setHandler(context);
context.addServlet(new ServletHolder(new SearchServlet()),
"/search");
LOGGER.info("server start.");
server.start();
server.join();
} catch (Exception e) {
e.printStackTrace();
}
}
}


/**
* <pre>
* Copyright baidu.com CDC [2000-2014]
* </pre>
*/
package test.servlet;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import test.utils.Tools;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* <pre>
* HelloServlet.java
* @author kanpiaoxue<br>
* @version 1.0
* Create Time 2014年9月2日 下午4:55:40<br>
* Description : HttpServlet
* </pre>
*/
public class SearchServlet extends HttpServlet {
private static final Logger LOGGER = LoggerFactory
.getLogger(SearchServlet.class);
/**
* <pre>
* </pre>
*/
private static final long serialVersionUID = -4012838481920999524L;
/**
* 写在这里的代码都是 POST 请求
*/
@Override
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String query = request.getParameter("query");
LOGGER.info(String.format("receive query: %s", query));
String result = "welcome to my server. It's a POST request.";
if (null != query && !query.trim().equals("")) {
result = query + ", " + result;
}
LOGGER.info(String.format("response is: %s", result));
Tools.printToJson(result, response);
}
/**
* 写在这里的代码都是 GET 请求
*/
@Override
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String query = request.getParameter("query");
LOGGER.info(String.format("receive query: %s", query));
String result = "welcome to my server. It's a GET request.";
if (null != query && !query.trim().equals("")) {
result = query + ", " + result;
}
LOGGER.info(String.format("response is: %s", result));
Tools.printToJson(result, response);
}
}


package test.utils;
import org.eclipse.jetty.server.Request;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.http.HttpServletResponse;
/**
* <pre>
* Tools.java
* @author kanpiaoxue<br>
* @version 1.0
* Create Time 2014年9月2日 下午4:57:06<br>
* Description : 工具类
* </pre>
*/
public class Tools {
private Tools() {
super();
}
/**
* <pre>
* @param baseRequest
* @param response
* @param result 需要返回给客户的结果
* @throws IOException
* 将结果 result 返回给客户
* </pre>
*/
public static void print(Request baseRequest, HttpServletResponse response,
String result) throws IOException {
response.setContentType("text/json;charset=utf-8");
response.setStatus(HttpServletResponse.SC_OK);
baseRequest.setHandled(true);
response.getWriter().println(result);
}

/**
* 直接输出 json 字符串
*
* @param json
*/
public static void printToJson(String json, HttpServletResponse response) {
try {
response.setCharacterEncoding("UTF-8");
response.setContentType("text/json");
response.setDateHeader("Expires", 0);
PrintWriter out = response.getWriter();
out.print(json);
out.flush();
out.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}

　　源码详见附件
　　我还有一篇问题，是用jetty和spring结合的： 

嵌入jetty的springMVC可运行jar的REST+
　　关于嵌入式 jetty 更多的内容请参考： http://wiki.eclipse.org/Jetty/Tutorial/Embedding_Jetty