Poco学习（二）

•  Poco JSON

- 生成

/////////////////// POCO::JSON /////////////////////
#include "Poco/JSON//Parser.h"
#include "Poco/Dynamic/Var.h"
#include <fstream>

void CreateJson()
{
    Poco::JSON::Object root, temp;
    Poco::JSON::Array province, cities;

// 1.
    //对中文的支持不好
    cities.add("大庆");
    cities.add("哈尔滨");
    temp.set("name", "黑龙江");
    temp.set("cities", cities);
    province.add(temp);
    
    cities.clear(); temp.clear();
    cities.add("深圳");
    cities.add("广州");
    temp.set("name", "广东");
    temp.set("cities", cities);
    province.add(temp);

    root.set("province", province);
    root.set("country", "中国");
    
    std::ostringstream osstr;
    root.stringify(osstr, 2);//中文显示不出
    std::string s = osstr.str();
    /* 结果：
{
  "country" : "中国",
  "province" : [
    {
      "cities" : [
        "u00B4u00F3u00C7u00EC",
        "u00B9u0FB6u0EF1u00F5"
      ],
      "name" : "u00BAu00DAu00C1uD82BuDF6D"
    },
    {
      "cities" : [
        "u00C9u00EEu00DBu00DA",
        "u00B9u00E3u00D6u00DD"
      ],
      "name" : "u00B9u3DAB"
    }
  ]
}    
    */

//2.
    cities.add("daqing");
    cities.add("haerbin");
    temp.set("name", "heilongjiang");
    temp.set("cities", cities);
    province.add(temp);

    cities.clear(); temp.clear();
    cities.add("shenzhen");
    cities.add("guangzhou");
    temp.set("name", "guangdong");
    temp.set("cities", cities);
    province.add(temp);

    root.set("province", province);
    root.set("country", "中国");


    Poco::Dynamic::Var js(root);
    std::string str =  js.toString();
    /* 结果如下
{
  "country" : "中国",
  "province" : [
    {
      "cities" : [
        "daqing",
        "haerbin"
      ],
      "name" : "heilongjiang"
    },
    {
      "cities" : [
        "shenzhen",
        "guangzhou"
      ],
      "name" : "guangdong"
    }
  ]
}
    */

    std::ofstream ofile("test.json");
    root.stringify(ofile, 4);
    ofile.close();
}
int main()
{
    CreateJson();
    return 0;
}

- 解析（sJson必须是UTF8编码的）

    try
    {
        std::string sJson = "{"name":"LiBai","friends":["DuFu","HEZHIZHANG"]}"; // "{"名字":"李白"}";
        Poco::JSON::Parser parser;
        //sJson必须是utf8的，可能只支持 7bit的ASCII码，因为有中文时解析出错：“No legal UTF8 found”
        Poco::Dynamic::Var ret = parser.parse(sJson);
        Poco::JSON::Object::Ptr pObj = ret.extract<Poco::JSON::Object::Ptr>();
        //1. use Object::Ptr
        std::string sName = pObj->get("name").toString();
        Poco::JSON::Array::Ptr pArr = pObj->getArray("friends");
        for (int i = 0; i < pArr->size(); ++i)
        {
            std::string s = pArr->get(i).toString();
        }
        for (auto it = pArr->begin(); it != pArr->end(); ++it)
        {
            std::string s = it->toString();
        }
        //2. use DynamicStruct
        Poco::DynamicStruct ds = *pObj;
        std::string sName2 = ds["name"];
        std::string sFriend1 = ds["friends"][0];
        std::string sFriend2 = ds["friends"][1];
    }
    catch (Poco::JSON::JSONException& e)
    {
        std::string sErr = std::string(e.what()) + "===" + e.message();
    }

- 生成和解析

    Poco::JSON::Object root, temp;
    Poco::JSON::Array province, cities;

    root.setEscapeUnicode(true);//汉字用Unicode表示，例如："黑龙江"->"u9ED1u9F99u6C5F"
    std::wstring wsTmp = L"大庆";
    cities.add(wsTmp);
    wsTmp = L"哈尔滨";
    cities.add(wsTmp);
    wsTmp = L"黑龙江";
    temp.set("name", wsTmp);
    temp.set("cities", cities);
    province.add(temp);
    root.set("province", province);
    std::wstring sC(L"中国");
    root.set("country", sC);

    Poco::Dynamic::Var js(root);
    std::string str =  js.toString();//自动转为utf8字符编码
    /* 虽然结果如下，但用Poco：：JSON可以解析
{
  "country" : "涓�浗",
  "province" : [
    {
      "cities" : [
        "u5927u5E86",
        "u54C8u5C14u6EE8"
      ],
      "name" : "u9ED1u9F99u6C5F"
    }
  ]
}
    */
    try
    {
        std::string sJson = str;//"{"name":"LiBai","friends":["DuFu","HEZHIZHANG"]}"; // "{"名字":"李白"}";
        Poco::JSON::Parser parser;
        //sJson必须是utf8的，可能只支持 7bit的ASCII码，因为有中文时解析出错：“No legal UTF8 found”
        Poco::Dynamic::Var ret = parser.parse(sJson);
        Poco::JSON::Object::Ptr pObj = ret.extract<Poco::JSON::Object::Ptr>();

        //2. use DynamicStruct
        Poco::DynamicStruct ds = *pObj;
        std::string stemp;
        std::string sName2 = ds["country"];
        UTF8_to_ANSI(sName2, stemp);//中国
        std::string sProvince = ds["province"][0]["name"];
        UTF8_to_ANSI(sProvince, stemp);//黑龙江
        std::string sCity1 = ds["province"][0]["cities"][0];
        UTF8_to_ANSI(sCity1, stemp);//大庆
        std::string sCity2 = ds["province"][0]["cities"][1];
        UTF8_to_ANSI(sCity2, stemp);//哈尔滨
    }
    catch (Poco::JSON::JSONException& e)
    {
        std::string sErr = std::string(e.what()) + "===" + e.message();
    }

注：UTF8_to_ANSI 函数，参见 my functions.h 的第3个。

•  Poco Base64 编码解码

基于字符串

#include <sstream>
#include <Poco/Base64Encoder.h>
#include <Poco/Base64Decoder.h>
#include <Poco/StreamCopier.h>
int main(int argc, char** argv)
{    
    //base64编码
    std::string s1("12345");
    std::stringstream ss;
    std::ostringstream oss;
    ss << s1;
    Poco::Base64Encoder encoder(oss);
    Poco::StreamCopier::copyStream(ss, encoder);
    encoder.close();//这句很重要
    std::string s2 = oss.str();//"MTIzNDU="

    ///////////////////////////////
    // 注意：若无 encoder.close();
    // 则， "123456" -> "MTIzNDU2"  ok
    //      "12345"  ->  "MTIz"     error. because of "MTIz" ->(123)
    ///////////////////////////////

    return 0;
}

    
    //解码
    std::stringstream ss;
    std::ostringstream oss;
    ss << "MTIzNDU2";
    Poco::Base64Decoder decoder(ss);
    Poco::StreamCopier::copyStream(decoder, oss);
    std::string s = oss.str();//"123456"
    //或者用下面的代替上两行
    //std::string s2;
    //Poco::StreamCopier::copyToString(decoder, s2);

//参考：https://blog.csdn.net/lizhi200404520/article/details/8860282
// 网上的例子
    {
        std::string s("0123", 4);
        std::ostringstream str;
        Poco::Base64Encoder encoder(str);
        encoder << s;
        encoder.close();
        std::string sRet = str.str();//"AAECAw=="
    }
    {
        std::istringstream istr("MTIzNDU=");
        Poco::Base64Decoder decoder(istr);
        std::string s;
        decoder >> s;//"12345"
    }

 Poco给的例子（基于文件流）

/////////////// 编码 ///////////////////////

#include "Poco/Base64Encoder.h"
#include "Poco/StreamCopier.h"
#include <iostream>
#include <fstream>


using Poco::Base64Encoder;
using Poco::StreamCopier;


int main(int argc, char** argv)
{
    if (argc != 3)
    {
        std::cout << "usage: " << argv[0] << ": <input_file> <output_file>" << std::endl
                  << "       read <input_file>, base64-encode it and write the result to <output_file>" << std::endl;
        return 1;
    }
    
    std::ifstream istr(argv[1], std::ios::binary);
    if (!istr)
    {
        std::cerr << "cannot open input file: " << argv[1] << std::endl;
        return 2;
    }
    
    std::ofstream ostr(argv[2]);
    if (!ostr)
    {
        std::cerr << "cannot open output file: " << argv[2] << std::endl;
        return 3;
    }
    
    Base64Encoder encoder(ostr);
    StreamCopier::copyStream(istr, encoder);
    
    if (!ostr)
    {
        std::cerr << "error writing output file: " << argv[2] << std::endl;
        return 4;
    }
    
    return 0;
}




////////////// 解码 ////////////////////////

#include "Poco/Base64Decoder.h"
#include "Poco/StreamCopier.h"
#include <iostream>
#include <fstream>


using Poco::Base64Decoder;
using Poco::StreamCopier;


int main(int argc, char** argv)
{
    if (argc != 3)
    {
        std::cout << "usage: " << argv[0] << ": <input_file> <output_file>" << std::endl
                  << "       read base64-encoded <input_file>, decode it and write the result to <output_file>" << std::endl;
        return 1;
    }
    
    std::ifstream istr(argv[1]);
    if (!istr)
    {
        std::cerr << "cannot open input file: " << argv[1] << std::endl;
        return 2;
    }
    
    std::ofstream ostr(argv[2], std::ios::binary);
    if (!ostr)
    {
        std::cerr << "cannot open output file: " << argv[2] << std::endl;
        return 3;
    }
    
    Base64Decoder decoder(istr);
    StreamCopier::copyStream(decoder, ostr);
    
    if (!ostr)
    {
        std::cerr << "error writing output file: " << argv[2] << std::endl;
        return 4;
    }
    
    return 0;
}

•  Poco MD5 加密

#include "Poco/MD5Engine.h"
#include "Poco/DigestStream.h"
#include "Poco/StreamCopier.h"
#include <fstream>
#include <iostream>
using Poco::DigestEngine;
using Poco::MD5Engine;
using Poco::DigestOutputStream;
using Poco::StreamCopier;

int main(int argc, char** argv)
{
    if (argc != 2)
    {
        std::cout << "usage: " << argv[0] << ": <input_file>" << std::endl
                  << "       create the MD5 digest for <input_file>" << std::endl;
        return 1;
    }
    
    std::ifstream istr(argv[1], std::ios::binary);
    if (!istr)
    {
        std::cerr << "cannot open input file: " << argv[1] << std::endl;
        return 2;
    }
    
    MD5Engine md5;
    DigestOutputStream dos(md5);
    StreamCopier::copyStream(istr, dos);
    dos.close();
    std::string sMD5 = DigestEngine::digestToHex(md5.digest());
    std::cout << DigestEngine::digestToHex(md5.digest()) << std::endl;
    
    return 0;
}

• Poco 压缩文件 解压文件 deflate inflate

压缩文件：

#include "Poco/DeflatingStream.h"
#include "Poco/StreamCopier.h"
#include <fstream>
using Poco::DeflatingOutputStream;
using Poco::StreamCopier;
int main()
{
    char* filename = "F:/test.xls";
    std::ifstream ifile(filename, std::ios::binary);
    if (!ifile.is_open())
        return -1;
    filename = "F:/test.zlib";
    std::ofstream ofile(filename, std::ios::binary);
    if (!ofile.is_open())
        return -1;

    // DeflatingOutputStream(std::ostream& ostr, DeflatingStreamBuf::StreamType type = DeflatingStreamBuf::STREAM_ZLIB, int level = Z_DEFAULT_COMPRESSION);
    // 有 zlib压缩（STREAM_ZLIB）和 gzip压缩（STREAM_GZIP）
    // level : 1~9 表示压缩的程度 /* compression levels */
    // #define Z_NO_COMPRESSION         0
    // #define Z_BEST_SPEED             1
    // #define Z_BEST_COMPRESSION       9
    // #define Z_DEFAULT_COMPRESSION  (-1)
    
    //DeflatingOutputStream deflator(ofile);//默认压缩
    //DeflatingOutputStream deflator(ofile, Poco::DeflatingStreamBuf::STREAM_ZLIB, 1);//最快压缩
    DeflatingOutputStream deflator(ofile, Poco::DeflatingStreamBuf::STREAM_ZLIB, 9);//最大压缩
    StreamCopier::copyStream(ifile, deflator);
    if (!ofile) //error writing output file
        return -2;
    // result：
    //默认压缩 Z_DEFAULT_COMPRESSION : 234K -> 67K
    //最快压缩 Z_BEST_SPEED : 234K -> 77K
    //最大压缩 Z_BEST_COMPRESSION : 234K -> 66K
    return 0;
}

解压文件：

//解压文件
#include "Poco/InflatingStream.h"
#include "Poco/StreamCopier.h"
#include <fstream>
using Poco::InflatingInputStream;
using Poco::StreamCopier;
int main()
{
    std::ifstream ifile("F:/test.zlib", std::ios::binary);
    if (!ifile.is_open())
        return -1;
    std::ofstream ofile("F:/test2.xls", std::ios::binary);
    if (!ofile.is_open())
        return -2;
    InflatingInputStream inflator(ifile);//默认参数：STREAM_ZLIB     若解压gzip，用 STREAM_GZIP
    StreamCopier::copyStream(inflator, ofile);
    if (!ofile)
        return -3;// error writing output file
    return 0;
}

注：gzip 压缩的文件，可以用WinRAR或7Z解压，但不知文件的后缀名。可以让输出文件名为 test.xls.gzip ，用WinRAR或7Z解压后就带文件后缀了。

•  poco 正则表达式

#include "Poco/RegularExpression.h"
#include <iostream>
using Poco::RegularExpression;
int main(int argc, char** argv)
{
    std::string pattern = "ig";
    int options = 0;    
    options += RegularExpression::RE_CASELESS;//不区分大小写
    options += RegularExpression::RE_EXTENDED;//忽略空白
    RegularExpression re(pattern, options);
    std::string line = "Slient night, holy night. ";
    RegularExpression::Match mtch;
    if (re.match(line, mtch))
    {
        int pos = mtch.offset;//匹配的位置
        int len = mtch.length;//匹配的长度
    }
        

    RegularExpression p("[0-9]+");
    std::string numstr = "12345ghk89760";
    std::string s;
    std::vector<std::string> vecStr;

    int n = p.extract(numstr, s);   //n=1， s=12345
    n = p.extract(numstr, 5, s); //n=1, s=89760
    
    bool b = p.match(numstr); //  b = false, 完全匹配时返回true
    b = p.match("14389274805");// b = true
    // 替换匹配(only first)
    n = p.subst(numstr, "*");   //numstr="*ghk89760"
    // 替换所有匹配到的内容
    n = p.subst(numstr, "*", Poco::RegularExpression::RE_GLOBAL);   //numstr="*ghk*"
    

    return 0;
}

•  poco 写日志 logger

#include "Poco/Logger.h"
#include "Poco/PatternFormatter.h"
#include "Poco/FormattingChannel.h"
#include "Poco/ConsoleChannel.h"
#include "Poco/FileChannel.h"
#include "Poco/Message.h"
using Poco::Logger;
using Poco::PatternFormatter;
using Poco::FormattingChannel;
using Poco::ConsoleChannel;
using Poco::FileChannel;
using Poco::Message;
int main(int argc, char** argv)
{
    //FormattingChannel* pFCFile = new FormattingChannel(new PatternFormatter("%Y-%m-%d %H:%M:%S.%c %N[%P]:%s:%q:%t"));
    FormattingChannel* pFCFile = new FormattingChannel(new PatternFormatter("[%Y-%m-%d %H:%M:%S.%c] [%s:%p]: %t"));
    pFCFile->setChannel(new FileChannel("D:/sample.log"));
    pFCFile->open();
    Logger& fileLogger = Logger::create("FileLogger", pFCFile, Message::PRIO_WARNING);//只有权限不低于指定的level，才写入

    fileLogger.error("An error message");//ok
    fileLogger.warning("A warning message");//ok

    fileLogger.information("An information message");//低于PRIO_WARNING，写不上

    poco_warning_f2(fileLogger, "A warning message with arguments: %d, %d", 1, 2);//ok

    Logger::get("FileLogger").error("Another error message");//ok

    return 0;
}

//------------------------------------------------------
enum Priority
    {
        PRIO_FATAL = 1,   /// A fatal error. The application will most likely terminate. This is the highest priority.
        PRIO_CRITICAL,    /// A critical error. The application might not be able to continue running successfully.
        PRIO_ERROR,       /// An error. An operation did not complete successfully, but the application as a whole is not affected.
        PRIO_WARNING,     /// A warning. An operation completed with an unexpected result.
        PRIO_NOTICE,      /// A notice, which is an information with just a higher priority.
        PRIO_INFORMATION, /// An informational message, usually denoting the successful completion of an operation.
        PRIO_DEBUG,       /// A debugging message.
        PRIO_TRACE        /// A tracing message. This is the lowest priority.
    };

•  poco 的 URL

#include "Poco/URI.h"
#include <iostream>
using Poco::URI;
int main(int argc, char** argv)
{
    URI uri1("http://www.appinf.com:81/sample?example-query#somewhere");
    
    std::cout << "Scheme:    " << uri1.getScheme() << std::endl // http
              << "Authority: " << uri1.getAuthority() << std::endl// www.appinf.com:81
              << "Path:      " << uri1.getPath() << std::endl// /sample
              << "Query:     " << uri1.getQuery() << std::endl// example-query
              << "Fragment:  " << uri1.getFragment() << std::endl;// somewhere
              
    URI uri2;
    uri2.setScheme("https");
    uri2.setAuthority("www.appinf.com");
    uri2.setPath("/another sample");
    std::cout << uri2.toString() << std::endl;
    
    return 0;
}

•  poco的UUID（UUID 是 通用唯一识别码（Universally Unique Identifier））

#include "Poco/UUID.h"
#include "Poco/UUIDGenerator.h"
#include "Poco/Exception.h"
#include <iostream>

using Poco::UUID;
using Poco::UUIDGenerator;
using Poco::Exception;

int main(int argc, char** argv)
{
    UUID uuid;
    
    std::string arg;
    if (argc > 1)
        arg = argv[1];//arg="jook"
    
    try
    {
        if (arg == "-random")
            uuid = UUIDGenerator::defaultGenerator().createRandom();
        else if (arg.empty())
            uuid = UUIDGenerator::defaultGenerator().create();
        else
            uuid = UUIDGenerator::defaultGenerator().createFromName(UUID::uri(), arg);
        
        std::string sRet = uuid.toString();//67440b59-4ad8-3f74-8bab-8b4ae76b4fc3
    }
    catch (Exception& exc)
    {
        std::cerr << exc.displayText() << std::endl;
        return 1;
    }
    
    return 0;
}

•  poco的读写配置文件，包括ini文件、properties文件、xml文件

  // ini文件
  #include "Poco/AutoPtr.h"
  #include "Poco/Util/IniFileConfiguration.h"
  #include <fstream>
  using Poco::AutoPtr;
  using Poco::Util::IniFileConfiguration;
  int main(int argc, char** argv)
  {
      try{
          const std::string path = "D:/test.ini";
          AutoPtr<IniFileConfiguration> pConf(new IniFileConfiguration(path));
          //注：大小写不敏感
          std::string title = pConf->getString("bookinfo.Title","UnKnown");//第二个参数是默认值
          std::string author = pConf->getString("bookInfo.author");//没有默认值时，若无该节点则抛异常Poco::NotFoundException
          //int value = pConf->getInt("BOOKinfo.price", -1);//抛异常Poco::SyntaxException   29.99 is not a integer.
          int value = pConf->getInt("BOOKinfo.PAGES", -1);
          std::string sPrice = pConf->getRawString("BOOKinfo.price", "default string");
  
          //写入配置(注意：IniFileConfiguration修改了，但test.ini没写不进去)
          AutoPtr<IniFileConfiguration> pConf2(new IniFileConfiguration("test.ini"));
          pConf2->setString("BOOKinfo.price2", "ppp");
          pConf2->setUInt("jjj", 90);
          
      }
      catch (Poco::Exception& e)
      {
          std::string s = e.displayText();
          return -1;
      }
  
      return 0;
  }

1. ini文件

/* D:/test.ini
[BookInfo]
title=Harry Potter
author =J.K. Rowling
price= 29.99
Pages = 2345
*/

// ini文件
#include "Poco/AutoPtr.h"
#include "Poco/Util/IniFileConfiguration.h"
#include <fstream>
using Poco::AutoPtr;
using Poco::Util::IniFileConfiguration;
int main(int argc, char** argv)
{
    try{
        const std::string path = "D:/test.ini";
        AutoPtr<IniFileConfiguration> pConf(new IniFileConfiguration(path));
        //注：大小写不敏感
        std::string title = pConf->getString("bookinfo.Title","UnKnown");//第二个参数是默认值
        std::string author = pConf->getString("bookInfo.author");//没有默认值时，若无该节点则抛异常Poco::NotFoundException
        //int value = pConf->getInt("BOOKinfo.price", -1);//抛异常Poco::SyntaxException   29.99 is not a integer.
        int value = pConf->getInt("BOOKinfo.PAGES", -1);
        std::string sPrice = pConf->getRawString("BOOKinfo.price", "default string");

        //写入配置(注意：IniFileConfiguration修改了，但test.ini没写不进去)
        AutoPtr<IniFileConfiguration> pConf2(new IniFileConfiguration("test.ini"));
        pConf2->setString("BOOKinfo.price2", "ppp");
        pConf2->setUInt("jjj", 90);
        
    }
    catch (Poco::Exception& e)
    {
        std::string s = e.displayText();
        return -1;
    }

    return 0;
}

2. properties文件

// test.properties
/*
#这是注释行，<key> = <value> 或者 <key> : <value>
BookInfo
BookInfo.title= Harry Potter
BookInfo.author =J.K. Rowling
BookInfo.price: 29.99
BookInfo.Pages = 2345
key.longValue: this is a Very lo
ng value
key.string :: we are: one.
key.test = tt=test
path : C:\Test.dat
*/

#include "Poco/AutoPtr.h"
#include "Poco/Util/PropertyFileConfiguration.h"
using Poco::AutoPtr;
using Poco::Util::PropertyFileConfiguration;
int main(int argc, char** argv)
{
    AutoPtr<PropertyFileConfiguration> pConf;
    pConf = new PropertyFileConfiguration("test.properties");
    try
    {//注意：properties中的属性名区分大小写
        std::string str = pConf->getString("BookInfo.title", "Unknown");//"Harry Potter"
        str = pConf->getString("BookInfo","--");// ""
        int value1 = pConf->getInt("BookInfo.Pages", -1); // "2345"
        str = pConf->getString("key.string", "");//": we are: one."
        std::string logV = pConf->getString("key.longValue");// "this is a Very long value"
        std::string path = pConf->getString("path");// "C:Test.dat"
        pConf->setString("key.test", "tt");//设置，但并没有写入配置文件test.properties中
        pConf->save("test.properties");//真正写入配置文件
    }
    catch (Poco::Exception& e)
    {
        std::string s = e.displayText();
        return -1;
    }
    return 0;
}

//写入后的格式被自动整理
//写入后的 test.properties
/*
BookInfo: 
BookInfo.Pages: 2345
BookInfo.author: J.K. Rowling
BookInfo.price: 29.99
BookInfo.title: Harry Potter
key.longValue: this is a Very long value
key.string: : we are: one.
key.test: tt
path: C:\Test.dat
*/

3. xml配置文件

/* test.xml
<?xml version="1.0" encoding="utf-8" ?>
<!--this is a comment.-->
<books>
    <book category="children" language="English">
        <title>Harry Potter</title>
        <author> J.K. Rowling </author>
        <price>29.99</price>
        <pages>521</pages>
    </book>
    <book category="science fiction"/>
    <prop5 id="first">value5</prop5>
    <prop5 id="second">value6</prop5>
    <ttt>中文</ttt>
</books>

*/

//xml配置文件
#include "Poco/AutoPtr.h"
#include "Poco/Util/XMLConfiguration.h"
#include "Poco/UnicodeConverter.h"
using Poco::AutoPtr;
using Poco::Util::XMLConfiguration;

int main(int argc, char** argv)
{
    try{//case sensitive
        AutoPtr<XMLConfiguration> pConfig(new XMLConfiguration("D:/test.xml"));
        std::string str = pConfig->getString("book.title", "--");// "Harry Potter"
        int n = pConfig->getInt("book.pages", -1);//"521"
        str = pConfig->getString("book.author", "");//" J.K. Rowling "
        str = pConfig->getString("book.category", "--");//"--"
        str = pConfig->getString("book[@language]", "default");//"English"
        str = pConfig->getString("book[@category]", "default");//"children"
        str = pConfig->getString("book[1][@category]");//"science fiction"
        str = pConfig->getString("prop5[@id=first]", "--");//"value5"
        str = pConfig->getString("prop5[@id='second']", "--");//"value6"
        str = pConfig->getString("ttt", "--");// "涓�枃"("中文"的utf8编码)
        std::wstring wsUnicode;
        Poco::UnicodeConverter::toUTF16(str, wsUnicode);//"中文"  utf8 -> Unicode(utf16) 
        //写入
        pConfig->setString("test", "12fg");
        pConfig->setString("test[@attr]", "sss");
        std::string sUtf8;
        Poco::UnicodeConverter::toUTF8(L"中文测试", sUtf8);//Unicode(utf16) -> utf8
        pConfig->setString("test2", sUtf8);
        pConfig->save("D:/test2.xml");
    }
    catch (Poco::Exception& e)
    {
        std::string s = e.displayText();
        return -1;
    }

    return 0;
}

/* save后
<!--this is a comment.-->
<books>
    <book category="children" language="English">
        <title>Harry Potter</title>
        <author> J.K. Rowling </author>
        <price>29.99</price>
        <pages>521</pages>
    </book>
    <book category="science fiction"/>
    <prop5 id="first">value5</prop5>
    <prop5 id="second">value6</prop5>
    <ttt>中文</ttt>
    <test attr="sss">12fg</test>
    <test2>中文测试</test2>
</books>

*/

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