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我对网络编程有点陌生，遇到了一些麻烦。我正在 Android 设备上创建一个 JSON 对象，通过 TCP 连接到 python 服务器，并发送 JSON 字符串。连接被接受，但我一直丢失字符串的结尾，所以

json.loads(json_string)

失败了。

这是相关的Android代码：

private class Worker implements Runnable
{
    @Override
    public void run()
    {
        //create the network socket
        try
        {
            socket = new Socket(address, 4242);
            Log.i(TAG, "timeout: " + socket.getSoTimeout());
        } 
        catch (IOException e)
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }


        packets = new ArrayList<JSONObject>();
        for (jobs.moveToFirst(); jobs.isAfterLast() == false; jobs.moveToNext())
        {
            String jobName = jobs.getString(jobs.getColumnIndex(JobMetaData.JobTableMetaData.JOB));

            Uri.Builder updated = new Uri.Builder();
            updated.scheme("content");
            updated.authority(JobMetaData.AUTHORITY);
            updated.appendPath(jobName);
            updated.appendPath("member");
            updated.appendPath(JobMetaData.MemberTableMetaData.CHANGED);
            updated.appendPath("true");

            Cursor changed = getContentResolver().query(updated.build(), null, null, null, null);

            Log.d(TAG, "number of members " + changed.getCount());

            //create a JSON object out of the editable properties
            for (changed.moveToFirst(); changed.isAfterLast() == false; changed.moveToNext())
            {
                JSONObject json = new JSONObject();

                for (String att : changed.getColumnNames())
                {
                    if (ListMetaData.validAtts.contains(att))
                    {
                        try
                        {
                            json.put(att, changed.getString(changed.getColumnIndex(att)));
                        } 
                        catch (JSONException e)
                        {
                            // TODO Auto-generated catch block
                            Log.d(TAG, "JSON exception in DatagramService");
                            e.printStackTrace();
                        }
                    }
                }

                //include the GUID and job name
                //for identification
                try
                {
                    json.put(JobMetaData.MemberTableMetaData.GUID,
                            changed.getString(changed.getColumnIndex(JobMetaData.MemberTableMetaData.GUID)));
                    json.put(JobMetaData.JobTableMetaData.JOB, jobName);
                } 
                catch (JSONException e)
                {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }

                packets.add(json);
            }
            changed.close();
        }

        Log.d(TAG, "entering send loop");
        try
        {
            out = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));
            out.flush();
        } 
        catch (IOException e1)
        {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        }

        for (JSONObject packet : packets)
        {   
            Log.d(TAG, "supposedly sending");
            try
            {
                //now write the data
                Log.d(TAG, "packet string: " + packet.toString());
                out.write(packet.toString());
                out.flush();
            }
            catch (IOException e)
            {

            }

        }

        try
        {
            out.write("Done");
            out.flush();
            out.close();
        } catch (IOException e)
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        stopSelf();
    }

我正在使用的测试服务器（用python编写）：

#!/usr/bin/env python

import SocketServer
import json

class MemberUpdateHandler(SocketServer.BaseRequestHandler):
    def setup(self):
        print self.client_address, "connected"

    def handle(self):
        while True:
            self.JSONString = self.request.recv(8192).strip()
            if self.JSONString == "Done":
                return
            self.handleJSON()
            self.update()

    def handleJSON(self):
        JSONMember = json.loads(self.JSONString)
        print "GUID:", JSONMember['ManufacturingGUID']
        print "Weight:", JSONMember['Weight']

    def update(self):
        print "do something here"


if __name__ == "__main__":
    ADDRESS = ''
    PORT = 4242
    HOST = (ADDRESS, PORT)

    s = SocketServer.ThreadingTCPServer(HOST, MemberUpdateHandler)
    s.serve_forever()

这是正在发送的字符串（很长）：

{"DetailCheckedBy":"","SketchRight":"","DetailLength":"142.75","DetailedDate":"**NOT SET**","EngineerVerifiedBothConns":"False","HoldStatus":"Not held","RevisionLevel":"No Revision","MemberNumber":"28","RequestVerifySectionSize":"False","TieForcesRight":"False","InputBy":"","IFCFinishDate_4":"**NOT SET**","IFCFinishDate_5":"**NOT SET**","Weight":"438.408","IFCTaskUID_1":"","IFCFinishDate_1":"**NOT SET**","ErectorOrder":"","IFCFinishDate_2":"**NOT SET**","IFCFinishDate_3":"**NOT SET**","IFCTaskUID_4":"","IFCTaskUID_5":"","IFCTaskUID_2":"","SketchLeft":"","IFCTaskUID_3":"","ErectorSequences":"","ReasonRejected":"","MemberCategory":"","EngineerVerifiedLeftConn":"False","BarcodeId":"","ManufacturingGUID":"42bbf9cc-52da-4712-a5fc-e37c5a544c14","aess":"False","FabricationComplete":"**NOT SET**","UserComment2":"","UserComment3":"","LoadNumber":"","UserComment1":"","ErectionBolted":"**NOT SET**","RequestVerifyLength":"False","RequestVerifyGrade":"False","Painted":"False","HeatCertNumber":"","Route1Description":"","IsExisting":"No","ReceivedFromApproval":"**NOT SET**","BackCheckedBy":"","BatchNumber":"","CostCodeReference":"","PONumber":"","Piecemark":"B_25","ReleasedForFabrication":"**NOT SET**","MemberDescription":"BEAM","EngineerVerifiedMemberReady":"False","IFCTaskName_2":"","IFCTaskName_1":"","IFCTaskName_4":"","RequestVerifyMemberPosition":"False","IFCTaskName_3":"","Erected":"**NOT SET**","RevisionCheckedBy_3":"","IFCTaskName_5":"","RevisionCheckedBy_2":"","RevisionCheckedBy_1":"","EngineerVerifiedLeftComments":"","RequestVerifyLeftConnMaterial":"False","RequestEngineerVerify":"False","RevisionCheckedDate_3":"**NOT SET**","RevisionCheckedDate_2":"**NOT SET**","RevisionCheckedDate_1":"**NOT SET**","EngineerVerifiedLength":"False","BackCheckedDate":"**NOT SET**","SubmittedForApproval":"**NOT SET**","EngineerVerifiedSpecial":"False","CostCodeDescription":"","IFCStartDate_5":"**NOT SET**","TieForcesLeft":"False","Fireproofed":"False","ErectorAvailable":"False","RequestVerifyRightConnMaterial":"False","DetailCheckedDate":"**NOT SET**","ErectorNonSteelSupported":"False","BeamPent":"False","StockStatus":"","Sequence":"1","RequestVerifyLeftLoad":"False","DetailFinalCheckDate":"**NOT SET**","ErectorMemberPlaced":"**NOT SET**","InstanceStatus":"","EngineerVerifiedRightConn":"False","DateReceived":"**NOT SET**","MemberType":"Beam","ModelCheckDate":"**NOT SET**","ReasonForHold":"","EngineerVerifiedRightComments":"","ReceivedOnJobSite":"**NOT SET**","RequestVerifyRightLoad":"False","CostCodePrice":"0.0","NestStatus":"","DateDue":"**NOT SET**","ShopSequence":"","EngineerVerifiedSectionSize":"False","ActualLength":"144","InputDate":"**NOT SET**","ErectorCity":"Unknown","EngineerVerifiedSpecial_comments":"","Route4Description":"","EngineerVerifiedGrade":"False","RightLocation":"0.0xx144.0xx156.0xx","IFCFinishTime_2":"","IFCFinishTime_1":"","IFCFinishTime_4":"","Route3Description":"","IFCFinishTime_3":"","LoadStatus":"","ErectorLongitude":"","DateModelCompleted":"61299957600000","Grade":"##SEKRIT KODE!!##","IFCFinishTime_5":"","Route2Description":"","RequestVerifyCamber":"False","ProjectedFabricationComplete":"**NOT SET**","DetailedBy":"","DetailFinalCheckBy":"","Description":"W8x35","ProjectedShippedDate":"**NOT SET**","NestName":"","IFCStartDate_2":"**NOT SET**","IFCStartTime_1":"","IFCStartDate_1":"**NOT SET**","IFCStartDate_4":"**NOT SET**","IFCStartDate_3":"**NOT SET**","IFCStartTime_5":"","IFCStartTime_4":"","IFCStartTime_3":"","DateHeld":"**NOT SET**","IFCStartTime_2":"","LeftLocation":"0.0xx0.0xx156.0xx","Job":"Mobile_x_x_x_x_Demo_x_x_x_x_IN_x_x_x_x_2011","SpecialCutWeld":"False","RejectedBy":"","ErectionWelded":"**NOT SET**","RequestVerifyRightConnConfig":"False","Vendor":"","PackageNumber":"","RejectedByErector":"**NOT SET**","ModelCheckedBy":"","ApprovalStatus":"Not reviewed","RequestVerifyLeftConnConfig":"False","ErectorLatitude":"","LotName":"","ActualShipDate":"**NOT SET**","NestId":""}

这是我从 python 服务器得到的错误：

ValueError: Unterminated string starting at: line 1 column 1435 (char 1435)

这意味着字符串已被截断为：

{"DetailCheckedBy":"","SketchRight":"","DetailLength":"142.75","DetailedDate":"**NOT SET**","EngineerVerifiedBothConns":"False","HoldStatus":"Not held","RevisionLevel":"No Revision","MemberNumber":"28","RequestVerifySectionSize":"False","TieForcesRight":"False","InputBy":"","IFCFinishDate_4":"**NOT SET**","IFCFinishDate_5":"**NOT SET**","Weight":"438.408","IFCTaskUID_1":"","IFCFinishDate_1":"**NOT SET**","ErectorOrder":"","IFCFinishDate_2":"**NOT SET**","IFCFinishDate_3":"**NOT SET**","IFCTaskUID_4":"","IFCTaskUID_5":"","IFCTaskUID_2":"","SketchLeft":"","IFCTaskUID_3":"","ErectorSequences":"","ReasonRejected":"","MemberCategory":"","EngineerVerifiedLeftConn":"False","BarcodeId":"","ManufacturingGUID":"42bbf9cc-52da-4712-a5fc-e37c5a544c14","aess":"False","FabricationComplete":"**NOT SET**","UserComment2":"","UserComment3":"","LoadNumber":"","UserComment1":"","ErectionBolted":"**NOT SET**","RequestVerifyLength":"False","RequestVerifyGrade":"False","Painted":"False","HeatCertNumber":"","Route1Description":"","IsExisting":"No","ReceivedFromApproval":"**NOT SET**","BackCheckedBy":"","BatchNumber":"","CostCodeReference":"","PONumber":"","Piecemark":"B_25","ReleasedForFabrication":"**NOT SET**","MemberDescription":"BEAM","EngineerVerifiedMemberReady":"False","IFCTaskName_2":"","IFCTaskName_1":"","IFCTaskName_4":"","RequestVerifyMemberPosition":"False","IFCTaskName_3":"","Erected":"**NOT SET**","RevisionCheckedBy_3":"","IFCTaskName_

任何帮助将不胜感激。提前致谢。

更新：

我已经更新了代码以反映我的修补。服务器收到的字符串现在是

{"DetailCheckedBy":"","SketchRight":"","DetailLength":"142.75","DetailedDate":"**NOT SET**","EngineerVerifiedBothConns":"False","HoldStatus":"Not held","RevisionLevel":"No Revision","MemberNumber":"28","RequestVerifySectionSize":"False","TieForcesRight":"False","InputBy":"","IFCFinishDate_4":"**NOT SET**","IFCFinishDate_5":"**NOT SET**","Weight":"438.408","IFCTaskUID_1":"","IFCFinishDate_1":"**NOT SET**","ErectorOrder":"","IFCFinishDate_2":"**NOT SET**","IFCFinishDate_3":"**NOT SET**","IFCTaskUID_4":"","IFCTaskUID_5":"","IFCTaskUID_2":"","SketchLeft":"","IFCTaskUID_3":"","ErectorSequences":"","ReasonRejected":"","MemberCategory":"","EngineerVerifiedLeftConn":"False","BarcodeId":"","ManufacturingGUID":"42bbf9cc-52da-4712-a5fc-e37c5a544c14","aess":"False","FabricationComplete":"**NOT SET**","UserComment2":"","UserComment3":"","LoadNumber":"","UserComment1":"","ErectionBolted":"**NOT SET**","RequestVerifyLength":"False","RequestVerifyGrade":"False","Painted":"False","HeatCertNumber":"","Route1Description":"","IsExisting":"No","ReceivedFromApproval":"**NOT SET**","BackCheckedBy":"","BatchNumber":"","CostCodeReference":"","PONumber":"","Piecemark":"B_25","ReleasedForFabrication":"**NOT SET**","MemberDescription":"BEAM","EngineerVerifiedMemberReady":"False","IFCTaskName_2":"","IFCTaskName_1":"","IFCTaskName_4":"","RequestVerifyMemberPosition":"False","IFCTaskName_3":"","Erected":"**NOT SET**","RevisionCheckedBy_3":"","IFCTaskName_5":"","RevisionCheckedBy_2":"","RevisionCheckedBy_1":"","EngineerVerifiedLeftComments":"","RequestVerifyLeftConnMaterial":"False","RequestEngineerVerify":"False","RevisionCheckedDate_3":"**NOT SET**","RevisionCheckedDate_2":"**NOT SET**","RevisionCheckedDate_1":"**NOT SET**","EngineerVerifiedLength":"False","BackCheckedDate":"**NOT SET**","SubmittedForApproval":"**NOT SET**","EngineerVerifiedSpecial":"False","CostCodeDescription":"","IFCStartDate_5":"**NOT SET**","TieForcesLeft":"False","Fireproofed":"False","ErectorAvailable":"False","RequestVerifyRightConnMaterial":"False","DetailCheckedDate":"**NOT SET**","ErectorNonSteelSupported":"False","BeamPent":"False","StockStatus":"","Sequence":"1","RequestVerifyLeftLoad":"False","DetailFinalCheckDate":"**NOT SET**","ErectorMemberPlaced":"**NOT SET**","InstanceStatus":"","EngineerVerifiedRightConn":"False","DateReceived":"**NOT SET**","MemberType":"Beam","ModelCheckDate":"**NOT SET**","ReasonForHold":"","EngineerVerifiedRightComments":"","ReceivedOnJobSite":"**NOT SET**","RequestVerifyRightLoad":"False","CostCodePrice":"0.0","NestStatus":"","DateDue":"**NOT SET**","ShopSequence":"","EngineerVerifiedSectionSize":"False","ActualLength":"144","InputDate":"**NOT SET**","ErectorCity":"Unknown","EngineerVerifiedSpecial_comments":"","Route4Description":"","EngineerVerifiedGrade":"False","RightLocation":"0.0xx144.0xx156.0xx","IFCFinishTime_2":"","IFCFinishTime_1":"","IFCFinishTime_4":"","Route3Description":"","IFCFinishTime_3":"","LoadStatus":"","ErectorLongitude":"","DateModelCompleted":"61299957600000","Grade":"##SEKRIT KODE!!##","IFCFinishTime_5":"","Route2Description":"","RequestVerifyCamber":"False","ProjectedFabricationComplete":"**NOT SET**","DetailedBy":"","DetailFinalCheckBy":"","Description":"W8x35","ProjectedShippedDate":"**NOT SET**","NestName":"","IFCStartDate_2":"**NOT SET**","IFCStartTime_1":"","IFCStartDate_1":"**NOT SET**","IFCStartDate_4":"**NOT SET**","IFCStartDate_3":"**NOT SET**","IFCStartTime_5":"","IFCStartTime_4":"","IFCStartTime_3":"","DateHeld":"**NOT SET**","IFCStartTime_2":"","LeftLocation":"0.0xx0.0xx156.0xx","Job":"Mobile_x_x_x_x_Demo_x_x_x_x_IN_x_x_x_x_2011","SpecialCutWeld":"False","RejectedBy":"","ErectionWelded":"**NOT SET**","RequestVerifyRightConnConfig":"False","Vendor":"","PackageNumber":"","RejectedByErector":"**NOT SET**","ModelCheckedBy":"","ApprovalStatus":"Not reviewed","RequestVerifyLeftConnConfig":"False","ErectorLatitude":"","LotName":"","ActualShipDate":"**NOT SET**","NestId":""}Done

接着是一堆空白。够了，gedit 无法加载所有内容。前一步后退两步。：/

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2 回答 2

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sizeof(int) 在两个设备上可能不一样。所以如果你想传递一个二进制整数，你可能应该硬编码一些东西。

如果你评估 int('\001\002\003\004\005\006\007\010')，你不太可能得到你想要的，我相信这与你在 Python 代码中所做的很接近. 一方面，两个设备的字节序可能不同，另一方面，int() 想要评估 ASCII 或其他编码，而不是原始的字节序相关整数。

在 python 方面，您可能会发现这很有用： http ://stromberg.dnsalias.org/~strombrg/bufsock.html

我不确定您正在使用的 out.write()，但在 send() 的较低级别，不能保证您的整个缓冲区将被写入单个 send() - 它可以提前停止并且只返回发送了多少。希望 java 可以像 bufsock 为 python 所做的那样保护您免受这些细节的影响。

于 2012-07-09T19:46:26.110 回答
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为什么您“假设”字符串已被截断？print看看它到底是什么。

此外，正在发送的字符串（如您发布的那样）未包含在 中{}，这意味着它不是正确的 JSON ...我试图将其复制/粘贴到解释器中，这会引发ValueError：

ValueError: Extra data: line 1 column 17 - line 1 column 3952 (char 17 - 3952)

我把它封闭起来，{}它起作用了。您应该尝试查看您在 python 端接收到的字符串实际上是什么，然后您才能真正看到发生了什么。我还假设，既然您看到发送的“完成”，那么内容应该已经完全发送。

于 2012-07-11T12:53:05.037 回答