thrift概述

Apache Thrift 是FaceBook实现的一种跨平台的远程服务调用(RPC)的框架。它采用接口描述语言(IDL)定义并创建服务，传输数据采用二进制格式，相对于XML和Json等常用数据传输方式体积更小。

首先一个完整的RPC模块主要分三部分：

1.服务层(service):RPC接口的定义与实现

2.协议层(protocol):RPC报文格式和数据编码格式

3.传输层(transport):实现底层的通信(如socket)以及系统相关的功能(如事件循环、多线程)

如上图所示，图中黄色部分是用户实现的业务逻辑，褐色部分是根据Thrift定义的服务接口描述文件生成的客户端和服务端代码框架，红色部分是根据Thrift文件生成代码实现数据的读写操作。红色部分以下是Thrift的传输体系、协议以及底层的I/O通信。

一个thrift简单实例过程：

1.写Thrift定义文件（.thrift）

 namespace java com.eviac.blog.samples.thrift.server  // defines the namespace   

 typedef i32 int  //typedefs to get convenient names for your types  

 service AdditionService {  // defines the service to add two numbers
         int add(1:int n1, 2:int n2), //defines a method
 }

2.编译Thrift定义文件

thrift --gen <language> <Thrift filename>

对于java语言来说就是：

thrift --gen java add.thrift

执行完之后，在gen-java目录下你会发现构建RPC服务器和客户端有用的源代码，在本例中将生成一个AddtionService.java的文件。

现将生成的代码贴上：

 /**
  * Autogenerated by Thrift Compiler (0.8.0-xsb)
  *
  * DO NOT EDIT UNLESS YOU ARE SURE THAT YOU KNOW WHAT YOU ARE DOING
  *  @generated
  */

 import org.apache.thrift.scheme.IScheme;
 import org.apache.thrift.scheme.SchemeFactory;
 import org.apache.thrift.scheme.StandardScheme;

 import org.apache.thrift.scheme.TupleScheme;
 import org.apache.thrift.protocol.TTupleProtocol;
 import java.util.List;
 import java.util.ArrayList;
 import java.util.Map;
 import java.util.HashMap;
 import java.util.EnumMap;
 import java.util.Set;
 import java.util.HashSet;
 import java.util.EnumSet;
 import java.util.Collections;
 import java.util.BitSet;
 import java.nio.ByteBuffer;
 import java.util.Arrays;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;

 public class AdditionService {

   public interface Iface {

     public int add(int n1, int n2) throws org.apache.thrift.TException;

   }

   public interface AsyncIface {

     public void add(int n1, int n2, org.apache.thrift.async.AsyncMethodCallback<AsyncClient.add_call> resultHandler) throws org.apache.thrift.TException;

   }

   public static class Client extends org.apache.thrift.TServiceClient implements Iface {
     public static class Factory implements org.apache.thrift.TServiceClientFactory<Client> {
       public Factory() {}
       public Client getClient(org.apache.thrift.protocol.TProtocol prot) {
         return new Client(prot);
       }
       public Client getClient(org.apache.thrift.protocol.TProtocol iprot, org.apache.thrift.protocol.TProtocol oprot) {
         return new Client(iprot, oprot);
       }
     }

     public Client(org.apache.thrift.protocol.TProtocol prot)
     {
       super(prot, prot);
     }

     public Client(org.apache.thrift.protocol.TProtocol iprot, org.apache.thrift.protocol.TProtocol oprot) {
       super(iprot, oprot);
     }

     public int add(int n1, int n2) throws org.apache.thrift.TException
     {
       send_add(n1, n2);
       return recv_add();
     }

     public void send_add(int n1, int n2) throws org.apache.thrift.TException
     {
       add_args args = new add_args();
       args.setN1(n1);
       args.setN2(n2);
       sendBase("add", args);
     }

     public int recv_add() throws org.apache.thrift.TException
     {
       add_result result = new add_result();
       receiveBase(result, "add");
       if (result.isSetSuccess()) {
         return result.success;
       }
       throw new org.apache.thrift.TApplicationException(org.apache.thrift.TApplicationException.MISSING_RESULT, "add failed: unknown result");
     }

   }
   public static class AsyncClient extends org.apache.thrift.async.TAsyncClient implements AsyncIface {
     public static class Factory implements org.apache.thrift.async.TAsyncClientFactory<AsyncClient> {
       private org.apache.thrift.async.TAsyncClientManager clientManager;
       private org.apache.thrift.protocol.TProtocolFactory protocolFactory;
       public Factory(org.apache.thrift.async.TAsyncClientManager clientManager, org.apache.thrift.protocol.TProtocolFactory protocolFactory) {
         this.clientManager = clientManager;
         this.protocolFactory = protocolFactory;
       }
       public AsyncClient getAsyncClient(org.apache.thrift.transport.TNonblockingTransport transport) {
         return new AsyncClient(protocolFactory, clientManager, transport);
       }
     }

     public AsyncClient(org.apache.thrift.protocol.TProtocolFactory protocolFactory, org.apache.thrift.async.TAsyncClientManager clientManager, org.apache.thrift.transport.TNonblockingTransport transport) {
       super(protocolFactory, clientManager, transport);
     }

     public void add(int n1, int n2, org.apache.thrift.async.AsyncMethodCallback<add_call> resultHandler) throws org.apache.thrift.TException {
       checkReady();
       add_call method_call = new add_call(n1, n2, resultHandler, this, ___protocolFactory, ___transport);
       this.___currentMethod = method_call;
       ___manager.call(method_call);
     }

     public static class add_call extends org.apache.thrift.async.TAsyncMethodCall {
       private int n1;
       private int n2;
       public add_call(int n1, int n2, org.apache.thrift.async.AsyncMethodCallback<add_call> resultHandler, org.apache.thrift.async.TAsyncClient client, org.apache.thrift.protocol.TProtocolFactory protocolFactory, org.apache.thrift.transport.TNonblockingTransport transport) throws org.apache.thrift.TException {
         super(client, protocolFactory, transport, resultHandler, false);
         this.n1 = n1;
         this.n2 = n2;
       }

       public void write_args(org.apache.thrift.protocol.TProtocol prot) throws org.apache.thrift.TException {
         prot.writeMessageBegin(new org.apache.thrift.protocol.TMessage("add", org.apache.thrift.protocol.TMessageType.CALL, 0));
         add_args args = new add_args();
         args.setN1(n1);
         args.setN2(n2);
         args.write(prot);
         prot.writeMessageEnd();
       }

       public int getResult() throws org.apache.thrift.TException {
         if (getState() != org.apache.thrift.async.TAsyncMethodCall.State.RESPONSE_READ) {
           throw new IllegalStateException("Method call not finished!");
         }
         org.apache.thrift.transport.TMemoryInputTransport memoryTransport = new org.apache.thrift.transport.TMemoryInputTransport(getFrameBuffer().array());
         org.apache.thrift.protocol.TProtocol prot = client.getProtocolFactory().getProtocol(memoryTransport);
         return (new Client(prot)).recv_add();
       }
     }

   }

   public static class Processor<I extends Iface> extends org.apache.thrift.TBaseProcessor<I> implements org.apache.thrift.TProcessor {
     private static final Logger LOGGER = LoggerFactory.getLogger(Processor.class.getName());
     public Processor(I iface) {
       super(iface, getProcessMap(new HashMap<String, org.apache.thrift.ProcessFunction<I, ? extends org.apache.thrift.TBase>>()));
     }

     protected Processor(I iface, Map<String,  org.apache.thrift.ProcessFunction<I, ? extends  org.apache.thrift.TBase>> processMap) {
       super(iface, getProcessMap(processMap));
     }

     private static <I extends Iface> Map<String,  org.apache.thrift.ProcessFunction<I, ? extends  org.apache.thrift.TBase>> getProcessMap(Map<String,  org.apache.thrift.ProcessFunction<I, ? extends  org.apache.thrift.TBase>> processMap) {
       processMap.put("add", new add());
       return processMap;
     }

     private static class add<I extends Iface> extends org.apache.thrift.ProcessFunction<I, add_args> {
       public add() {
         super("add");
       }

       protected add_args getEmptyArgsInstance() {
         return new add_args();
       }

       protected boolean isOneway() {
        return false;
       }

       protected add_result getResult(I iface, add_args args) throws org.apache.thrift.TException {
         add_result result = new add_result();
         result.success = iface.add(args.n1, args.n2);
         result.setSuccessIsSet(true);
         return result;
       }
     }

   }

   public static class add_args implements org.apache.thrift.TBase<add_args, add_args._Fields>, java.io.Serializable, Cloneable   {
     private static final org.apache.thrift.protocol.TStruct STRUCT_DESC = new org.apache.thrift.protocol.TStruct("add_args");

     private static final org.apache.thrift.protocol.TField N1_FIELD_DESC = new org.apache.thrift.protocol.TField("n1", org.apache.thrift.protocol.TType.I32, (short)1);
     private static final org.apache.thrift.protocol.TField N2_FIELD_DESC = new org.apache.thrift.protocol.TField("n2", org.apache.thrift.protocol.TType.I32, (short)2);

     private static final Map<Class<? extends IScheme>, SchemeFactory> schemes = new HashMap<Class<? extends IScheme>, SchemeFactory>();
     static {
       schemes.put(StandardScheme.class, new add_argsStandardSchemeFactory());
       schemes.put(TupleScheme.class, new add_argsTupleSchemeFactory());
     }

     public int n1; // required
     public int n2; // required

     /** The set of fields this struct contains, along with convenience methods for finding and manipulating them. */
     public enum _Fields implements org.apache.thrift.TFieldIdEnum {
       N1((short)1, "n1"),
       N2((short)2, "n2");

       private static final Map<String, _Fields> byName = new HashMap<String, _Fields>();

       static {
         for (_Fields field : EnumSet.allOf(_Fields.class)) {
           byName.put(field.getFieldName(), field);
         }
       }

       /**
        * Find the _Fields constant that matches fieldId, or null if its not found.
        */
       public static _Fields findByThriftId(int fieldId) {
         switch(fieldId) {
           case 1: // N1
             return N1;
           case 2: // N2
             return N2;
           default:
             return null;
         }
       }

       /**
        * Find the _Fields constant that matches fieldId, throwing an exception
        * if it is not found.
        */
       public static _Fields findByThriftIdOrThrow(int fieldId) {
         _Fields fields = findByThriftId(fieldId);
         if (fields == null) throw new IllegalArgumentException("Field " + fieldId + " doesn't exist!");
         return fields;
       }

       /**
        * Find the _Fields constant that matches name, or null if its not found.
        */
       public static _Fields findByName(String name) {
         return byName.get(name);
       }

       private final short _thriftId;
       private final String _fieldName;

       _Fields(short thriftId, String fieldName) {
         _thriftId = thriftId;
         _fieldName = fieldName;
       }

       public short getThriftFieldId() {
         return _thriftId;
       }

       public String getFieldName() {
         return _fieldName;
       }
     }

     // isset id assignments
     private static final int __N1_ISSET_ID = 0;
     private static final int __N2_ISSET_ID = 1;
     private BitSet __isset_bit_vector = new BitSet(2);
     public static final Map<_Fields, org.apache.thrift.meta_data.FieldMetaData> metaDataMap;
     static {
       Map<_Fields, org.apache.thrift.meta_data.FieldMetaData> tmpMap = new EnumMap<_Fields, org.apache.thrift.meta_data.FieldMetaData>(_Fields.class);
       tmpMap.put(_Fields.N1, new org.apache.thrift.meta_data.FieldMetaData("n1", org.apache.thrift.TFieldRequirementType.DEFAULT,
           new org.apache.thrift.meta_data.FieldValueMetaData(org.apache.thrift.protocol.TType.I32          , "int")));
       tmpMap.put(_Fields.N2, new org.apache.thrift.meta_data.FieldMetaData("n2", org.apache.thrift.TFieldRequirementType.DEFAULT,
           new org.apache.thrift.meta_data.FieldValueMetaData(org.apache.thrift.protocol.TType.I32          , "int")));
       metaDataMap = Collections.unmodifiableMap(tmpMap);
       org.apache.thrift.meta_data.FieldMetaData.addStructMetaDataMap(add_args.class, metaDataMap);
     }

     public add_args() {
     }

     public add_args(
       int n1,
       int n2)
     {
       this();
       this.n1 = n1;
       setN1IsSet(true);
       this.n2 = n2;
       setN2IsSet(true);
     }

     /**
      * Performs a deep copy on <i>other</i>.
      */
     public add_args(add_args other) {
       __isset_bit_vector.clear();
       __isset_bit_vector.or(other.__isset_bit_vector);
       this.n1 = other.n1;
       this.n2 = other.n2;
     }

     public add_args deepCopy() {
       return new add_args(this);
     }

     @Override
     public void clear() {
       setN1IsSet(false);
       this.n1 = 0;
       setN2IsSet(false);
       this.n2 = 0;
     }

     public int getN1() {
       return this.n1;
     }

     public add_args setN1(int n1) {
       this.n1 = n1;
       setN1IsSet(true);
       return this;
     }

     public void unsetN1() {
       __isset_bit_vector.clear(__N1_ISSET_ID);
     }

     /** Returns true if field n1 is set (has been assigned a value) and false otherwise */
     public boolean isSetN1() {
       return __isset_bit_vector.get(__N1_ISSET_ID);
     }

     public void setN1IsSet(boolean value) {
       __isset_bit_vector.set(__N1_ISSET_ID, value);
     }

     public int getN2() {
       return this.n2;
     }

     public add_args setN2(int n2) {
       this.n2 = n2;
       setN2IsSet(true);
       return this;
     }

     public void unsetN2() {
       __isset_bit_vector.clear(__N2_ISSET_ID);
     }

     /** Returns true if field n2 is set (has been assigned a value) and false otherwise */
     public boolean isSetN2() {
       return __isset_bit_vector.get(__N2_ISSET_ID);
     }

     public void setN2IsSet(boolean value) {
       __isset_bit_vector.set(__N2_ISSET_ID, value);
     }

     public void setFieldValue(_Fields field, Object value) {
       switch (field) {
       case N1:
         if (value == null) {
           unsetN1();
         } else {
           setN1((Integer)value);
         }
         break;

       case N2:
         if (value == null) {
           unsetN2();
         } else {
           setN2((Integer)value);
         }
         break;

       }
     }

     public Object getFieldValue(_Fields field) {
       switch (field) {
       case N1:
         return Integer.valueOf(getN1());

       case N2:
         return Integer.valueOf(getN2());

       }
       throw new IllegalStateException();
     }

     /** Returns true if field corresponding to fieldID is set (has been assigned a value) and false otherwise */
     public boolean isSet(_Fields field) {
       if (field == null) {
         throw new IllegalArgumentException();
       }

       switch (field) {
       case N1:
         return isSetN1();
       case N2:
         return isSetN2();
       }
       throw new IllegalStateException();
     }

     @Override
     public boolean equals(Object that) {
       if (that == null)
         return false;
       if (that instanceof add_args)
         return this.equals((add_args)that);
       return false;
     }

     public boolean equals(add_args that) {
       if (that == null)
         return false;

       boolean this_present_n1 = true;
       boolean that_present_n1 = true;
       if (this_present_n1 || that_present_n1) {
         if (!(this_present_n1 && that_present_n1))
           return false;
         if (this.n1 != that.n1)
           return false;
       }

       boolean this_present_n2 = true;
       boolean that_present_n2 = true;
       if (this_present_n2 || that_present_n2) {
         if (!(this_present_n2 && that_present_n2))
           return false;
         if (this.n2 != that.n2)
           return false;
       }

       return true;
     }

     @Override
     public int hashCode() {
       return 0;
     }

     public int compareTo(add_args other) {
       if (!getClass().equals(other.getClass())) {
         return getClass().getName().compareTo(other.getClass().getName());
       }

       int lastComparison = 0;
       add_args typedOther = (add_args)other;

       lastComparison = Boolean.valueOf(isSetN1()).compareTo(typedOther.isSetN1());
       if (lastComparison != 0) {
         return lastComparison;
       }
       if (isSetN1()) {
         lastComparison = org.apache.thrift.TBaseHelper.compareTo(this.n1, typedOther.n1);
         if (lastComparison != 0) {
           return lastComparison;
         }
       }
       lastComparison = Boolean.valueOf(isSetN2()).compareTo(typedOther.isSetN2());
       if (lastComparison != 0) {
         return lastComparison;
       }
       if (isSetN2()) {
         lastComparison = org.apache.thrift.TBaseHelper.compareTo(this.n2, typedOther.n2);
         if (lastComparison != 0) {
           return lastComparison;
         }
       }
       return 0;
     }

     public _Fields fieldForId(int fieldId) {
       return _Fields.findByThriftId(fieldId);
     }

     public void read(org.apache.thrift.protocol.TProtocol iprot) throws org.apache.thrift.TException {
       schemes.get(iprot.getScheme()).getScheme().read(iprot, this);
     }

     public void write(org.apache.thrift.protocol.TProtocol oprot) throws org.apache.thrift.TException {
       schemes.get(oprot.getScheme()).getScheme().write(oprot, this);
     }

     @Override
     public String toString() {
       StringBuilder sb = new StringBuilder("add_args(");
       boolean first = true;

       sb.append("n1:");
       sb.append(this.n1);
       first = false;
       if (!first) sb.append(", ");
       sb.append("n2:");
       sb.append(this.n2);
       first = false;
       sb.append(")");
       return sb.toString();
     }

     public void validate() throws org.apache.thrift.TException {
       // check for required fields
     }

     private void writeObject(java.io.ObjectOutputStream out) throws java.io.IOException {
       try {
         write(new org.apache.thrift.protocol.TCompactProtocol(new org.apache.thrift.transport.TIOStreamTransport(out)));
       } catch (org.apache.thrift.TException te) {
         throw new java.io.IOException(te);
       }
     }

     private void readObject(java.io.ObjectInputStream in) throws java.io.IOException, ClassNotFoundException {
       try {
         // it doesn't seem like you should have to do this, but java serialization is wacky, and doesn't call the default constructor.
         __isset_bit_vector = new BitSet(1);
         read(new org.apache.thrift.protocol.TCompactProtocol(new org.apache.thrift.transport.TIOStreamTransport(in)));
       } catch (org.apache.thrift.TException te) {
         throw new java.io.IOException(te);
       }
     }

     private static class add_argsStandardSchemeFactory implements SchemeFactory {
       public add_argsStandardScheme getScheme() {
         return new add_argsStandardScheme();
       }
     }

     private static class add_argsStandardScheme extends StandardScheme<add_args> {

       public void read(org.apache.thrift.protocol.TProtocol iprot, add_args struct) throws org.apache.thrift.TException {
         org.apache.thrift.protocol.TField schemeField;
         iprot.readStructBegin();
         while (true)
         {
           schemeField = iprot.readFieldBegin();
           if (schemeField.type == org.apache.thrift.protocol.TType.STOP) {
             break;
           }
           switch (schemeField.id) {
             case 1: // N1
               if (schemeField.type == org.apache.thrift.protocol.TType.I32) {
                 struct.n1 = iprot.readI32();
                 struct.setN1IsSet(true);
               } else {
                 org.apache.thrift.protocol.TProtocolUtil.skip(iprot, schemeField.type);
               }
               break;
             case 2: // N2
               if (schemeField.type == org.apache.thrift.protocol.TType.I32) {
                 struct.n2 = iprot.readI32();
                 struct.setN2IsSet(true);
               } else {
                 org.apache.thrift.protocol.TProtocolUtil.skip(iprot, schemeField.type);
               }
               break;
             default:
               org.apache.thrift.protocol.TProtocolUtil.skip(iprot, schemeField.type);
           }
           iprot.readFieldEnd();
         }
         iprot.readStructEnd();

         // check for required fields of primitive type, which can't be checked in the validate method
         struct.validate();
       }

       public void write(org.apache.thrift.protocol.TProtocol oprot, add_args struct) throws org.apache.thrift.TException {
         struct.validate();

         oprot.writeStructBegin(STRUCT_DESC);
         oprot.writeFieldBegin(N1_FIELD_DESC);
         oprot.writeI32(struct.n1);
         oprot.writeFieldEnd();
         oprot.writeFieldBegin(N2_FIELD_DESC);
         oprot.writeI32(struct.n2);
         oprot.writeFieldEnd();
         oprot.writeFieldStop();
         oprot.writeStructEnd();
       }

     }

     private static class add_argsTupleSchemeFactory implements SchemeFactory {
       public add_argsTupleScheme getScheme() {
         return new add_argsTupleScheme();
       }
     }

     private static class add_argsTupleScheme extends TupleScheme<add_args> {

       @Override
       public void write(org.apache.thrift.protocol.TProtocol prot, add_args struct) throws org.apache.thrift.TException {
         TTupleProtocol oprot = (TTupleProtocol) prot;
         BitSet optionals = new BitSet();
         if (struct.isSetN1()) {
           optionals.set(0);
         }
         if (struct.isSetN2()) {
           optionals.set(1);
         }
         oprot.writeBitSet(optionals, 2);
         if (struct.isSetN1()) {
           oprot.writeI32(struct.n1);
         }
         if (struct.isSetN2()) {
           oprot.writeI32(struct.n2);
         }
       }

       @Override
       public void read(org.apache.thrift.protocol.TProtocol prot, add_args struct) throws org.apache.thrift.TException {
         TTupleProtocol iprot = (TTupleProtocol) prot;
         BitSet incoming = iprot.readBitSet(2);
         if (incoming.get(0)) {
           struct.n1 = iprot.readI32();
           struct.setN1IsSet(true);
         }
         if (incoming.get(1)) {
           struct.n2 = iprot.readI32();
           struct.setN2IsSet(true);
         }
       }
     }

   }

   public static class add_result implements org.apache.thrift.TBase<add_result, add_result._Fields>, java.io.Serializable, Cloneable   {
     private static final org.apache.thrift.protocol.TStruct STRUCT_DESC = new org.apache.thrift.protocol.TStruct("add_result");

     private static final org.apache.thrift.protocol.TField SUCCESS_FIELD_DESC = new org.apache.thrift.protocol.TField("success", org.apache.thrift.protocol.TType.I32, (short)0);

     private static final Map<Class<? extends IScheme>, SchemeFactory> schemes = new HashMap<Class<? extends IScheme>, SchemeFactory>();
     static {
       schemes.put(StandardScheme.class, new add_resultStandardSchemeFactory());
       schemes.put(TupleScheme.class, new add_resultTupleSchemeFactory());
     }

     public int success; // required

     /** The set of fields this struct contains, along with convenience methods for finding and manipulating them. */
     public enum _Fields implements org.apache.thrift.TFieldIdEnum {
       SUCCESS((short)0, "success");

       private static final Map<String, _Fields> byName = new HashMap<String, _Fields>();

       static {
         for (_Fields field : EnumSet.allOf(_Fields.class)) {
           byName.put(field.getFieldName(), field);
         }
       }

       /**
        * Find the _Fields constant that matches fieldId, or null if its not found.
        */
       public static _Fields findByThriftId(int fieldId) {
         switch(fieldId) {
           case 0: // SUCCESS
             return SUCCESS;
           default:
             return null;
         }
       }

       /**
        * Find the _Fields constant that matches fieldId, throwing an exception
        * if it is not found.
        */
       public static _Fields findByThriftIdOrThrow(int fieldId) {
         _Fields fields = findByThriftId(fieldId);
         if (fields == null) throw new IllegalArgumentException("Field " + fieldId + " doesn't exist!");
         return fields;
       }

       /**
        * Find the _Fields constant that matches name, or null if its not found.
        */
       public static _Fields findByName(String name) {
         return byName.get(name);
       }

       private final short _thriftId;
       private final String _fieldName;

       _Fields(short thriftId, String fieldName) {
         _thriftId = thriftId;
         _fieldName = fieldName;
       }

       public short getThriftFieldId() {
         return _thriftId;
       }

       public String getFieldName() {
         return _fieldName;
       }
     }

     // isset id assignments
     private static final int __SUCCESS_ISSET_ID = 0;
     private BitSet __isset_bit_vector = new BitSet(1);
     public static final Map<_Fields, org.apache.thrift.meta_data.FieldMetaData> metaDataMap;
     static {
       Map<_Fields, org.apache.thrift.meta_data.FieldMetaData> tmpMap = new EnumMap<_Fields, org.apache.thrift.meta_data.FieldMetaData>(_Fields.class);
       tmpMap.put(_Fields.SUCCESS, new org.apache.thrift.meta_data.FieldMetaData("success", org.apache.thrift.TFieldRequirementType.DEFAULT,
           new org.apache.thrift.meta_data.FieldValueMetaData(org.apache.thrift.protocol.TType.I32          , "int")));
       metaDataMap = Collections.unmodifiableMap(tmpMap);
       org.apache.thrift.meta_data.FieldMetaData.addStructMetaDataMap(add_result.class, metaDataMap);
     }

     public add_result() {
     }

     public add_result(
       int success)
     {
       this();
       this.success = success;
       setSuccessIsSet(true);
     }

     /**
      * Performs a deep copy on <i>other</i>.
      */
     public add_result(add_result other) {
       __isset_bit_vector.clear();
       __isset_bit_vector.or(other.__isset_bit_vector);
       this.success = other.success;
     }

     public add_result deepCopy() {
       return new add_result(this);
     }

     @Override
     public void clear() {
       setSuccessIsSet(false);
       this.success = 0;
     }

     public int getSuccess() {
       return this.success;
     }

     public add_result setSuccess(int success) {
       this.success = success;
       setSuccessIsSet(true);
       return this;
     }

     public void unsetSuccess() {
       __isset_bit_vector.clear(__SUCCESS_ISSET_ID);
     }

     /** Returns true if field success is set (has been assigned a value) and false otherwise */
     public boolean isSetSuccess() {
       return __isset_bit_vector.get(__SUCCESS_ISSET_ID);
     }

     public void setSuccessIsSet(boolean value) {
       __isset_bit_vector.set(__SUCCESS_ISSET_ID, value);
     }

     public void setFieldValue(_Fields field, Object value) {
       switch (field) {
       case SUCCESS:
         if (value == null) {
           unsetSuccess();
         } else {
           setSuccess((Integer)value);
         }
         break;

       }
     }

     public Object getFieldValue(_Fields field) {
       switch (field) {
       case SUCCESS:
         return Integer.valueOf(getSuccess());

       }
       throw new IllegalStateException();
     }

     /** Returns true if field corresponding to fieldID is set (has been assigned a value) and false otherwise */
     public boolean isSet(_Fields field) {
       if (field == null) {
         throw new IllegalArgumentException();
       }

       switch (field) {
       case SUCCESS:
         return isSetSuccess();
       }
       throw new IllegalStateException();
     }

     @Override
     public boolean equals(Object that) {
       if (that == null)
         return false;
       if (that instanceof add_result)
         return this.equals((add_result)that);
       return false;
     }

     public boolean equals(add_result that) {
       if (that == null)
         return false;

       boolean this_present_success = true;
       boolean that_present_success = true;
       if (this_present_success || that_present_success) {
         if (!(this_present_success && that_present_success))
           return false;
         if (this.success != that.success)
           return false;
       }

       return true;
     }

     @Override
     public int hashCode() {
       return 0;
     }

     public int compareTo(add_result other) {
       if (!getClass().equals(other.getClass())) {
         return getClass().getName().compareTo(other.getClass().getName());
       }

       int lastComparison = 0;
       add_result typedOther = (add_result)other;

       lastComparison = Boolean.valueOf(isSetSuccess()).compareTo(typedOther.isSetSuccess());
       if (lastComparison != 0) {
         return lastComparison;
       }
       if (isSetSuccess()) {
         lastComparison = org.apache.thrift.TBaseHelper.compareTo(this.success, typedOther.success);
         if (lastComparison != 0) {
           return lastComparison;
         }
       }
       return 0;
     }

     public _Fields fieldForId(int fieldId) {
       return _Fields.findByThriftId(fieldId);
     }

     public void read(org.apache.thrift.protocol.TProtocol iprot) throws org.apache.thrift.TException {
       schemes.get(iprot.getScheme()).getScheme().read(iprot, this);
     }

     public void write(org.apache.thrift.protocol.TProtocol oprot) throws org.apache.thrift.TException {
       schemes.get(oprot.getScheme()).getScheme().write(oprot, this);
       }

     @Override
     public String toString() {
       StringBuilder sb = new StringBuilder("add_result(");
       boolean first = true;

       sb.append("success:");
       sb.append(this.success);
       first = false;
       sb.append(")");
       return sb.toString();
     }

     public void validate() throws org.apache.thrift.TException {
       // check for required fields
     }

     private void writeObject(java.io.ObjectOutputStream out) throws java.io.IOException {
       try {
         write(new org.apache.thrift.protocol.TCompactProtocol(new org.apache.thrift.transport.TIOStreamTransport(out)));
       } catch (org.apache.thrift.TException te) {
         throw new java.io.IOException(te);
       }
     }

     private void readObject(java.io.ObjectInputStream in) throws java.io.IOException, ClassNotFoundException {
       try {
         read(new org.apache.thrift.protocol.TCompactProtocol(new org.apache.thrift.transport.TIOStreamTransport(in)));
       } catch (org.apache.thrift.TException te) {
         throw new java.io.IOException(te);
       }
     }

     private static class add_resultStandardSchemeFactory implements SchemeFactory {
       public add_resultStandardScheme getScheme() {
         return new add_resultStandardScheme();
       }
     }

     private static class add_resultStandardScheme extends StandardScheme<add_result> {

       public void read(org.apache.thrift.protocol.TProtocol iprot, add_result struct) throws org.apache.thrift.TException {
         org.apache.thrift.protocol.TField schemeField;
         iprot.readStructBegin();
         while (true)
         {
           schemeField = iprot.readFieldBegin();
           if (schemeField.type == org.apache.thrift.protocol.TType.STOP) {
             break;
           }
           switch (schemeField.id) {
             case 0: // SUCCESS
               if (schemeField.type == org.apache.thrift.protocol.TType.I32) {
                 struct.success = iprot.readI32();
                 struct.setSuccessIsSet(true);
               } else {
                 org.apache.thrift.protocol.TProtocolUtil.skip(iprot, schemeField.type);
               }
               break;
             default:
               org.apache.thrift.protocol.TProtocolUtil.skip(iprot, schemeField.type);
           }
           iprot.readFieldEnd();
         }
         iprot.readStructEnd();

         // check for required fields of primitive type, which can't be checked in the validate method
         struct.validate();
       }

       public void write(org.apache.thrift.protocol.TProtocol oprot, add_result struct) throws org.apache.thrift.TException {
         struct.validate();

         oprot.writeStructBegin(STRUCT_DESC);
         oprot.writeFieldBegin(SUCCESS_FIELD_DESC);
         oprot.writeI32(struct.success);
         oprot.writeFieldEnd();
         oprot.writeFieldStop();
         oprot.writeStructEnd();
       }

     }

     private static class add_resultTupleSchemeFactory implements SchemeFactory {
       public add_resultTupleScheme getScheme() {
         return new add_resultTupleScheme();
       }
     }

     private static class add_resultTupleScheme extends TupleScheme<add_result> {

       @Override
       public void write(org.apache.thrift.protocol.TProtocol prot, add_result struct) throws org.apache.thrift.TException {
         TTupleProtocol oprot = (TTupleProtocol) prot;
         BitSet optionals = new BitSet();
         if (struct.isSetSuccess()) {
           optionals.set(0);
         }
         oprot.writeBitSet(optionals, 1);
         if (struct.isSetSuccess()) {
           oprot.writeI32(struct.success);
         }
       }

       @Override
       public void read(org.apache.thrift.protocol.TProtocol prot, add_result struct) throws org.apache.thrift.TException {
         TTupleProtocol iprot = (TTupleProtocol) prot;
         BitSet incoming = iprot.readBitSet(1);
         if (incoming.get(0)) {
           struct.success = iprot.readI32();
           struct.setSuccessIsSet(true);
         }
       }
     }

   }

 }

3.写一个service handler(也可以叫serviceImpl)

Service handler 类必须实现 AdditionService.Iface接口。AdditionServiceHandler.java代码如下：

 import org.apache.thrift.TException;

 public class AdditionServiceHandler implements AdditionService.Iface{

     @Override
     public int add(int n1, int n2) throws TException {
         // TODO Auto-generated method stub
         return n1 + n2;
     }

 }

4.写一个简单的服务器

下面的示例代码是一个简单的Thrift服务器。可以看到下面的代码中有一段是注释了的，可以去掉注释来启用多线程服务器。
示例服务器（MyServer.java）

 import org.apache.thrift.transport.TServerSocket;
 import org.apache.thrift.transport.TServerTransport;
 import org.apache.thrift.server.TServer;
 import org.apache.thrift.server.TServer.Args;
 import org.apache.thrift.server.TSimpleServer;  

 public class MyServer {  

  public static void StartsimpleServer(AdditionService.Processor<AdditionServiceHandler> processor) {
   try {
    TServerTransport serverTransport = new TServerSocket(9090);
    TServer server = new TSimpleServer(
      new Args(serverTransport).processor(processor));  

    // Use this for a multithreaded server
    // TServer server = new TThreadPoolServer(new
    // TThreadPoolServer.Args(serverTransport).processor(processor));  

    System.out.println("Starting the simple server...");
    server.serve();
   } catch (Exception e) {
    e.printStackTrace();
   }
  }  

  public static void main(String[] args) {
   StartsimpleServer(new AdditionService.Processor<AdditionServiceHandler>(new AdditionServiceHandler()));
  }  

 }

5.写一个简单的客户端

下面的例子是一个使用Java写的客户端短使用AdditionService的服务。

 import org.apache.thrift.TException;
 import org.apache.thrift.protocol.TBinaryProtocol;
 import org.apache.thrift.protocol.TProtocol;
 import org.apache.thrift.transport.TSocket;
 import org.apache.thrift.transport.TTransport;
 import org.apache.thrift.transport.TTransportException;  

 public class AdditionClient {  

  public static void main(String[] args) {  

   try {
    TTransport transport;  

    transport = new TSocket("localhost", 9090);
    transport.open();  

    TProtocol protocol = new TBinaryProtocol(transport);
    AdditionService.Client client = new AdditionService.Client(protocol);  

    System.out.println(client.add(100, 200));  

    transport.close();
   } catch (TTransportException e) {
    e.printStackTrace();
   } catch (TException x) {
    x.printStackTrace();
   }
  }  

 }

运行服务端代码（MyServer.java）将会看到下面的输出。

Starting the simple server...

然后运行客户端代码（AdditionClient.java），将会看到如下输出。

300

Thrift主要由五个部分组成：

系统类型以及IDL编译器：负责由用户给定的IDL文件生成相应语言的接口代码。

Tprotocol:实现RPC的协议层，可以选择多种不同的对象串行化方式，如JSON,Binary.

Transport:实现RPC的传输层，同样可以选择不同的传输层实现，如socket,非阻塞的socket等。

Tprocessor:作为协议层和用户提供的服务实现之间的纽带，负责调用服务实现的接口。

Tserver:聚合TProtocol,TTransport和TProcessor几个对象。

上述的这5个部件都是在 Thrift 的源代码中通过为不同语言提供库来实现的，这些库的代码在 Thrift 源码目录的 lib 目录下面，在使用 Thrift 之前需要先熟悉与自己的语言对应的库提供的接口。

数据类型

Thrift 脚本可定义的数据类型包括以下几种类型：

• 基本类型：

• bool：布尔值，true 或 false，对应 Java 的 boolean
• byte：8 位有符号整数，对应 Java 的 byte
• i16：16 位有符号整数，对应 Java 的 short
• i32：32 位有符号整数，对应 Java 的 int
• i64：64 位有符号整数，对应 Java 的 long
• double：64 位浮点数，对应 Java 的 double
• string：未知编码文本或二进制字符串，对应 Java 的 String

• 结构体类型：
  • struct：定义公共的对象，类似于 C 语言中的结构体定义，在 Java 中是一个 JavaBean
• 容器类型：
  • list：对应 Java 的 ArrayList
  • set：对应 Java 的 HashSet
  • map：对应 Java 的 HashMap
• 异常类型：
  • exception：对应 Java 的 Exception
• 服务类型：
  • service：对应服务的类

协议

Thrift 可以让用户选择客户端与服务端之间传输通信协议的类别，在传输协议上总体划分为文本 (text) 和二进制 (binary) 传输协议，为节约带宽，提高传输效率，一般情况下使用二进制类型的传输协议为多数，有时还会使用基于文本类型的协议，这需要根据项目 / 产品中的实际需求。常用协议有以下几种：

TBinaryProtocol —— 二进制编码格式进行数据传输

TCompactProtocol —— 高效率的、密集的二进制编码格式进行数据传输

TJSONProtocol —— 使用 JSON 的数据编码协议进行数据传输

TSimpleJSONProtocol —— 只提供 JSON 只写的协议，适用于通过脚本语言解析

传输层

常用的传输层有以下几种：

1.TSocket —— 使用阻塞式 I/O 进行传输，是最常见的模式

2.TFramedTransport —— 使用非阻塞方式，按块的大小进行传输，类似于 Java 中的 NIO

若使用 TFramedTransport 传输层，其服务器必须修改为非阻塞的服务类型，TNonblockingServerTransport 类是构建非阻塞 socket 的抽象类，TNonblockingServerSocket 类继承 TNonblockingServerTransport

3.TNonblockingTransport —— 使用非阻塞方式，用于构建异步客户端

服务端类型

常见的服务端类型有以下几种：

1.TSimpleServer —— 单线程服务器端使用标准的阻塞式 I/O

2.TThreadPoolServer —— 多线程服务器端使用标准的阻塞式 I/O

3.TNonblockingServer —— 多线程服务器端使用非阻塞式 I/O

本文参考以及引用：http://www.ibm.com/developerworks/cn/java/j-lo-apachethrift/

http://my.oschina.net/jack230230/blog/66041