Mina工具类v1.5

完整版见https://jadyer.github.io/2013/07/12/mina-tcp-http-server/

package com.cucpay.fundswap.util;import java.net.InetSocketAddress;import java.nio.charset.Charset;import java.util.concurrent.TimeUnit;import org.apache.mina.core.buffer.IoBuffer;import org.apache.mina.core.future.ConnectFuture;import org.apache.mina.core.future.ReadFuture;import org.apache.mina.core.service.IoConnector;import org.apache.mina.core.session.AttributeKey;import org.apache.mina.core.session.IoSession;import org.apache.mina.filter.codec.CumulativeProtocolDecoder;import org.apache.mina.filter.codec.ProtocolCodecFilter;import org.apache.mina.filter.codec.ProtocolDecoderOutput;import org.apache.mina.filter.codec.ProtocolEncoderAdapter;import org.apache.mina.filter.codec.ProtocolEncoderOutput;import org.apache.mina.transport.socket.nio.NioSocketConnector;/** * 使用Mina2.x发送报文的工具类 * @see 详细说明请参阅我的博客http://blog.csdn.net/jadyer/article/details/8088068 * @version v1.5 * @history v1.1-->编码器和解码器中的字符处理,升级为Mina2.x提供的<code>putString()</code>方法来处理 * @history v1.2-->解码器采用CumulativeProtocolDecoder实现,以适应应答报文被拆分多次后发送Client的情况 * @history v1.3-->修复BUG:请求报文有误时,Server可能返回非约定报文,此时会抛java.lang.NumberFormatException * @history v1.4-->增加全局异常捕获 * @history v1.5-->由于本工具类的作用是同步的客户端,故取消IoHandler设置,但注意必须setUseReadOperation(true) * @update Jul 27, 2013 10:21:01 AM * @create Oct 3, 2012 12:42:21 PM * @author 玄玉<http://blog.csdn.net/jadyer> */public class MinaUtil {private MinaUtil(){}/** * 发送TCP消息 * @see 当通信发生异常时,如Fail to get session....返回<code>"MINA_SERVER_ERROR"</code>字符串 * @param message   待发送报文的中文字符串形式 * @param ipAddress 远程主机的IP地址 * @param port      远程主机的端口号 * @param charset   该方法与远程主机间通信报文为编码字符集(编码为byte[]发送到Server) * @return 远程主机响应报文的字符串形式 */public static String sendTCPMessage(String message, String ipAddress, int port, String charset){IoConnector connector = new NioSocketConnector();connector.setConnectTimeoutMillis(1000);connector.getSessionConfig().setUseReadOperation(true); //同步的客户端,必须设置此项,其默认为falseconnector.getFilterChain().addLast("codec", new ProtocolCodecFilter(new ClientProtocolEncoder(charset), new ClientProtocolDecode(charset)));//connector.setHandler(this); //作为同步的客户端,可以不需要IoHandler,Mina会自动添加一个默认的IoHandler实现,即AbstractIoConnectorIoSession session = null;Object respData = null;try{ConnectFuture connectFuture = connector.connect(new InetSocketAddress(ipAddress, port));connectFuture.awaitUninterruptibly();          //等待连接成功,相当于将异步执行转为同步执行session = connectFuture.getSession();          //获取连接成功后的会话对象session.write(message).awaitUninterruptibly(); //由于上面已经设置setUseReadOperation(true),故IoSession.read()方法才可用ReadFuture readFuture = session.read();        //因其内部使用BlockingQueue,故Server端用之可能会内存泄漏,但Client端可适当用之if(readFuture.awaitUninterruptibly(90, TimeUnit.SECONDS)){ //Wait until the message is receivedrespData = readFuture.getMessage();                    //Get the received message}else{LogUtil.getLogger().info("读取[/" + ipAddress + ":" + port + "]超时");}}catch(Exception e){LogUtil.getLogger().error("请求通信[/" + ipAddress + ":" + port + "]偶遇异常,堆栈轨迹如下", e);}finally{if(session != null){//关闭IoSession,该操作是异步的,true为立即关闭,false为所有写操作都flush后关闭//这里仅仅是关闭了TCP的连接通道,并未关闭Client端程序session.close(true);//客户端发起连接时,会请求系统分配相关的文件句柄,而在连接失败时记得释放资源,否则会造成文件句柄泄露//当总的文件句柄数超过系统设置值时[ulimit -n],则抛异常"java.io.IOException: Too many open files",导致新连接无法创建,服务器挂掉//所以,若不关闭的话,其运行一段时间后可能抛出too many open files异常,导致无法连接session.getService().dispose();}}return respData==null ? "MINA_SERVER_ERROR" : respData.toString();}/** * 客户端编码器 * @see 将Client的报文编码后发送到Server */private static class ClientProtocolEncoder extends ProtocolEncoderAdapter {private final String charset;public ClientProtocolEncoder(String charset){this.charset = charset;}@Overridepublic void encode(IoSession session, Object message, ProtocolEncoderOutput out) throws Exception {IoBuffer buffer = IoBuffer.allocate(100).setAutoExpand(true);//二者等效--><code>buffer.put(message.toString().getBytes(charset))</code>buffer.putString(message.toString(), Charset.forName(charset).newEncoder());buffer.flip();out.write(buffer);}}/** * 客户端解码器 * @see 解码Server的响应报文给Client * @see 样例报文[000064100030010000120121101210419100000000000028`18622233125`10`] */private static class ClientProtocolDecode extends CumulativeProtocolDecoder {private final String charset;//注意这里使用了Mina自带的AttributeKey类来定义保存在IoSession中对象的键值,其可有效防止键值重复//通过查询AttributeKey类源码发现,它的构造方法采用的是"类名+键名+AttributeKey的hashCode"的方式private final AttributeKey CONTEXT = new AttributeKey(getClass(), "context");public ClientProtocolDecode(String charset){this.charset = charset;}private Context getContext(IoSession session){Context context = (Context)session.getAttribute(CONTEXT);if(null == context){context = new Context();session.setAttribute(CONTEXT, context);}return context;}@Overrideprotected boolean doDecode(IoSession session, IoBuffer in, ProtocolDecoderOutput out) throws Exception {Context ctx = this.getContext(session);IoBuffer buffer = ctx.innerBuffer;int messageCount = ctx.getMessageCount();while(in.hasRemaining()){    //判断position和limit之间是否有元素buffer.put(in.get());    //get()读取buffer的position的字节,然后position+1if(messageCount++ == 5){ //约定:报文的前6个字符串表示报文总长度,不足6位则左侧补0buffer.flip();       //Set limit=position and position=0 and mark=-1//当Server的响应报文中含0x00时,Mina2.x的buffer.getString(fieldSize, decoder)方法会break//该方法的处理细节,详见org.apache.mina.core.buffer.AbstractIoBuffer类的第1718行源码,其说明如下//Reads a NUL-terminated string from this buffer using the specified decoder and returns it//ctx.setMessageLength(Integer.parseInt(buffer.getString(6, decoder)));byte[] messageLength = new byte[6];buffer.get(messageLength);try{//请求报文有误时,Server可能返回非约定报文,此时会抛java.lang.NumberFormatExceptionctx.setMessageLength(Integer.parseInt(new String(messageLength, charset)));}catch(NumberFormatException e){ctx.setMessageLength(in.limit());}buffer.limit(in.limit()); //让两个IoBuffer的limit相等}}ctx.setMessageCount(messageCount);if(ctx.getMessageLength() == buffer.position()){buffer.flip();byte[] message = new byte[buffer.limit()];buffer.get(message);out.write(new String(message, charset));ctx.reset();return true;}else{return false;}}private class Context{private final IoBuffer innerBuffer; //用于累积数据的IoBufferprivate int messageCount;           //记录已读取的报文字节数private int messageLength;          //记录已读取的报文头标识的报文长度public Context(){innerBuffer = IoBuffer.allocate(100).setAutoExpand(true);}public int getMessageCount() {return messageCount;}public void setMessageCount(int messageCount) {this.messageCount = messageCount;}public int getMessageLength() {return messageLength;}public void setMessageLength(int messageLength) {this.messageLength = messageLength;}public void reset(){this.innerBuffer.clear(); //Set limit=capacity and position=0 and mark=-1this.messageCount = 0;this.messageLength = 0;}}}}