Thrift在Android上的客户端实现(二):文件传输

在上一篇文章Thrift在Android上的客户端实现中，我介绍了应该如何通过Thrift实现Android平台对服务器代码的远程调用。本篇内容继续讲解如何通过Thrift实现Android平台向服务器传输文件。

一、定义接口

1.桌面上新建thrift接口文件FileIface.thrift

/**
* 文件名为FileIface.thrift
* 基于：thrift-0.10.0
**/
namespace java com.younghong.thriftTest //定义命名空间，把该类所处的包名写在这里

struct FileChunk{
1:string fileName
2:i64 offset
3:i64 size
4:binary data
}
service FileIface{
        i64 uploadFile(1:FileChunk fileChunk)
}

2.把上面的thrift接口编译成java接口：运行cmd，输入“cd desktop”后回车，切换到FileIface.thrift所在的桌面路径。然后接着输入“thrift -gen Java FileIface.thrift”后回车，会在桌面生成gen-java文件夹，该文件夹中的FileIface.java文件就是我们需要的java接口，FileChunk.java是生成的Bean对象。

二、服务端实现

1.把刚才的java接口文件FileIface.java和FileChunk.java拷贝到项目中，然后新建类FileImp，实现FileIface.Iface 接口。

package com.younghong.thriftTest;

import java.io.File;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.nio.channels.FileChannel;

import org.apache.thrift.TException;

public class FileImp implements FileIface.Iface {

    public long uploadFile(FileChunk fileChunk) throws TException {
        // new出本地File
        File file = new File("E:\\img.jpg");
        try {
            file.createNewFile();
            RandomAccessFile stream = new RandomAccessFile(file, "rw");
            stream.seek(fileChunk.offset);
            System.out.println(fileChunk.offset+":"+fileChunk.size+":"+fileChunk.data.array().length);
            FileChannel theFileChannel = stream.getChannel();
            theFileChannel.write(fileChunk.data);
            theFileChannel.force(true);
            theFileChannel.close();
            stream.close();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return 0;
    }
}

2.在入口函数中开启服务。因为要同时开启两个服务，所以代码要进行部分改动，如下所示：

package com.younghong.thriftTest;

import org.apache.thrift.TMultiplexedProcessor;
import org.apache.thrift.TProcessorFactory;
import org.apache.thrift.protocol.TBinaryProtocol;
import org.apache.thrift.server.TServer;
import org.apache.thrift.server.TThreadPoolServer;
import org.apache.thrift.transport.TFramedTransport;
import org.apache.thrift.transport.TServerSocket;
import org.apache.thrift.transport.TServerTransport;
import org.apache.thrift.transport.TTransportException;

/**
 * Hello world!
 *
 */
public class App {

    public static void main(String[] args) {
        try {
            // 实现反转字符串的Processor,传入实现类ReverseImp
            ReverseIface.Processor reverseProcessor = new ReverseIface.Processor(new ReverseImp());
            FileIface.Processor fileProcessor = new FileIface.Processor(new FileImp());
            // 构建Thrift通信协议，设置其中的参数
            TServerTransport serverTransport = new TServerSocket(8080);
            TMultiplexedProcessor processor = new TMultiplexedProcessor();
            processor.registerProcessor("reverse", reverseProcessor);
            processor.registerProcessor("uploadFile", fileProcessor);
            // 根据设定好的参数，构建server，并启动server
            TThreadPoolServer.Args arg = new TThreadPoolServer.Args(serverTransport);
            arg.protocolFactory(new TBinaryProtocol.Factory());
            arg.transportFactory(new TFramedTransport.Factory());
            arg.processorFactory(new TProcessorFactory(processor));
            TServer server = new TThreadPoolServer(arg);
            server.serve();// 启动服务
        } catch (TTransportException e) {
            e.printStackTrace();
        }
    }
}

三、Android平台代码

1.添加读写SD卡权限，把刚才的java接口文件FileIface.java和FileChunk.java拷贝到项目中，修改MainActivity的onClick方法。(此处把button的功能直接修改成成了上传文件)

package com.younghong.thriftdemo;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;

import org.apache.thrift.protocol.TBinaryProtocol;
import org.apache.thrift.protocol.TMultiplexedProtocol;
import org.apache.thrift.transport.TFramedTransport;
import org.apache.thrift.transport.TSocket;
import org.apache.thrift.transport.TTransport;

import java.io.File;
import java.io.FileInputStream;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }


    public void onClick(View view) {
        //获取输入框的信息
        EditText editText = (EditText) findViewById(R.id.editText);
        final String strParam = editText.getText().toString();
        //开启线程，执行网络访问操作
        new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    //构建Thrift传输和协议
                    TTransport tTransport = getTTransport();
                    TBinaryProtocol protocol = new TBinaryProtocol(tTransport);
                    TMultiplexedProtocol mp1 = new TMultiplexedProtocol(protocol, "uploadFile");
                    //构建客户端,传入字符串进行反转操作
                    FileIface.Client client = new FileIface.Client(mp1);
                    File file = new File(strParam);
                    FileChunk fileChunk = new FileChunk();

                    FileInputStream fis = new FileInputStream(file);
                    // 1.从FileInputStream对象获取文件通道FileChannel
                    FileChannel channel = fis.getChannel();
                    long size = channel.size();
                    // 2.从通道读取文件内容
                    ByteBuffer byteBuffer = ByteBuffer.allocate(8192);
                    // channel.read(ByteBuffer) 方法就类似于 inputstream.read(byte)
                    // 每次read都将读取 allocate 个字节到ByteBuffer
                    long offset = 0;
                    while (offset < file.length()) {
//                        channel.position(offset);
                        channel.read(byteBuffer);
                        byteBuffer.flip();
                        fileChunk.offset = offset;
                        fileChunk.data = byteBuffer;
                        fileChunk.size = file.length();
                        fileChunk.fileName = "";
                        System.out.println(fileChunk.offset + ":" + fileChunk.size);
                        long returnMsg = client.uploadFile(fileChunk);
                        byteBuffer.clear();
                        offset += 8192;
                    }
                    tTransport.close();
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }).start();
    }

    //构建Thrift传输协议
    private TTransport getTTransport() throws Exception {
        try {
            //主机、端口、超时
            TSocket tSocket = new TSocket("172.16.36.146", 8080, 5000);
            //根据socket构建thrift
            TTransport tTransport = new TFramedTransport(tSocket);
            if (!tTransport.isOpen()) {
                tTransport.open();
            }
            return tTransport;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }
}

2.安装apk，在EditText中输入手机一张jpg图片的路径，点击Button后，如果能在电脑的E盘根目录打开img.jpg，则证明上传成功。

四、总结

thrift传输文件比较麻烦，并且不好控制。本文也只是实现了最简单的上传功能，性能、安全、异常捕获等内容未做详细判断。