Java和jni(獲得指定文件創(chuàng)建時間)

/前言：在我寫這篇文章之前，我說說我的碰到這個問題的起因。公司讓我寫一個jar包，需要獲得指定文件的創(chuàng)建日期（日期必須是完整地年月日時分秒）。對于javajdk1.7來說很容易，因為1.7給了我們獲得創(chuàng)建日期的接口。但是對于jdk1.6來說，那就是一個老大難，沒有提供，只提供了獲得最后修改日期的接口。個人收集整理勿做商業(yè)用途對于jdk1.6，當然我也查過，請教過好多人，給出了解決辦法，那就是使用Java的Runtime去調(diào)用當前操作系統(tǒng)的指令獲得文件的創(chuàng)建日期：個人收集整理勿做商業(yè)用途例如在windows下，publicStringgetFileCreateDate(File_file){Filefile=_file;

try{

Processls_proc=Runtime.getRuntime().exec(

"cmd.exe/cdir"+file.getAbsolutePath()+"/tc");

個人收集整理勿做商業(yè)用途BufferedReaderbr=newBufferedReader(newInputStreamReader(ls_proc.getInputStream()));

個人收集整理勿做商業(yè)用途for(inti=0;i<5;i++){

br.readLine();

}

Stringstuff=br.readLine();

StringTokenizerst=newStringTokenizer(stuff);

StringdateC=st.nextToken();

Stringtime=st.nextToken();

Stringdatetime=dateC.concat(time);

SimpleDateFormatformatter1=newSimpleDateFormat("yyyy-MM-ddhh:mm:ss");

個人收集整理勿做商業(yè)用途SimpleDateFormatformatter2=newSimpleDateFormat(

個人收集整理勿做商業(yè)用途"yyyy/MM/ddHH:mm");

datetime=formatter1.format(formatter2.parse(datetime));

個人收集整理勿做商業(yè)用途

br.close();

returndatetime;

}catch(Exceptione){

returnnull;

}

}引用：/question/535215288.html但是這個方法只能或得到文件的年月日時分，不能獲得到秒。為了獲得到秒，最后使用了jni。步驟：1、使用c和C++寫一個獲得文件創(chuàng)建時間的類#pragmaonce//Modifythefollowingdefinesifyouhavetotargetaplatformpriortotheonesspecifiedbelow.//RefertoMSDNforthelatestinfooncorrespondingvaluesfordifferentplatforms.#ifndefWINVER//AllowuseoffeaturesspecifictoWindowsXPorlater.#defineWINVER0x0501//ChangethistotheappropriatevaluetotargetotherversionsofWindows.#endif#ifndef_WIN32_WINNT//AllowuseoffeaturesspecifictoWindowsXPorlater.#define_WIN32_WINNT0x0501//ChangethistotheappropriatevaluetotargetotherversionsofWindows.#endif#ifndef_WIN32_WINDOWS//AllowuseoffeaturesspecifictoWindows98orlater.#define_WIN32_WINDOWS0x0410//ChangethistotheappropriatevaluetotargetWindowsMeorlater.#endif#ifndef_WIN32_IE//AllowuseoffeaturesspecifictoIE6.0orlater.#define_WIN32_IE0x0600//ChangethistotheappropriatevaluetotargetotherversionsofIE.#endif#defineWIN32_LEAN_AND_MEAN//Excluderarely-usedstufffromWindowsheaders//WindowsHeaderFiles:#include<windows.h>個人收集整理勿做商業(yè)用途

//WinFileTime.cpp:DefinestheentrypointfortheDLLapplication.//#include"stdafx.h"#include"FileClass/FileTimeEx.h"#ifdef_MANAGED#pragmamanaged(push,off)#endifBOOLAPIENTRYDllMain(HMODULEhModule,DWORDul_reason_for_call,LPVOIDlpReserved){returnTRUE;}JNIEXPORTjstringJNICALLJava_checkfile_WinFileTime_getFileCreationTime(JNIEnv*env,jobjectcls,jstringFileName){HANDLEhFile;FILETIMEcreationTime;FILETIMElastAccessTime;FILETIMElastWriteTime;FILETIMEcreationLocalTime;SYSTEMTIMEcreationSystemTime;jstringresult;charfileTimeString[30];hFile=CreateFileA((char*)env->GetStringUTFChars(FileName,0),GENERIC_READ,FILE_SHARE_READ|FILE_SHARE_WRITE,NULL,OPEN_EXISTING,0,NULL);if(hFile==INVALID_HANDLE_VALUE)returnenv->NewStringUTF("");if(GetFileTime(hFile,&creationTime,&lastAccessTime,&lastWriteTime)){if(FileTimeToLocalFileTime(&creationTime,&creationLocalTime)){if(FileTimeToSystemTime(&creationLocalTime,&creationSystemTime)){sprintf_s(fileTimeString,"d-d-dd:d:d\0",creationSystemTime.wYear,creationSystemTime.wMonth,creationSystemTime.wDay,creationSystemTime.wHour,creationSystemTime.wMinute,creationSystemTime.wSecond),result=env->NewStringUTF(fileTimeString);}elseresult=env->NewStringUTF("");}elseresult=env->NewStringUTF("");}elseresult=env->NewStringUTF("");CloseHandle(hFile);returnresult;}#ifdef_MANAGED#pragmamanaged(pop)#endif個人收集整理勿做商業(yè)用途2、然后生成動態(tài)鏈接文件（*.dll），將這個文件放到C:\Windows\System32和你的javajdk目錄下D:\ProgramFiles\Java\jdk1.6.0_18\jre\bin。個人收集整理勿做商業(yè)用途3、java文件中寫法publicfinalclassWinFileTime{static{System.loadLibrary("WinFileTime");}privatestaticnativeStringgetFileCreationTime(StringfileName);publicstaticStringgetCreationTime(StringfileName){returngetFileCreationTime(fileName);}}}個人收集整理勿做商業(yè)用途注意：頭文件與類文件的方法名必須與java中的類名一直，如：c中是Java_checkfile_WinFileTime_getFileCreationTime,那么java中就是checkfile.WinFileTime.getFileCreationTime(checkfile是包名，WinFileTime是類名，getFileCreationTime是方法名).個人收集整理勿做商業(yè)用途jdk1.7方法：下載一個jdk1.7幫助文檔，看看這個類BasicFileAttributeView。Pathpath=Paths.get(filePath);

BasicFileAttributeViewbasicview=Files.getFi