Java中的getInputStream + BufferedReader + FileReader

Question

我正在嘗試使用ProcessBuilder和.getInputStream（）在Java中運行C應用程序。我認爲哪個應用程序的輸出？那麼我認爲我需要使用包裝在BufferedReader中的FileReader？我不確定如何連接進程和FileReader？

我翻譯一些C（在評論）：

void run(){ 
     //FILE *POINTS; 
     //I think the above points to the file? so I'm using a InputStream object. 

     private InputStream POINTS; 

      //generate octree for this case 
      //============================= 
      //sprintf(befehl,"%soconv -f %s %s %s \"%s\" > %s\n","",material_file, BlindRadianceFiles_Combined, geometry_file, sun_rad, octree); 
      //note I've replaced "befehl" with "cmd". 

      String.format(cmd, "%soconv -f %s %s %s \"%s\" > %s\n","",material_file, BlindRadianceFiles_Combined, geometry_file, sun_rad, octree); 

      //POINTS = popen(befehl,"r"); 
      //Info on POPEN in C. For instance, if you wanted to read the output of your program, you'd use popen("program", "r"). On the other hand, if you want to write to its input, you would use popen("program", "w"). 

      Process process = new ProcessBuilder(cmd).start(); 
      POINTS = process.getInputStream(); 

      //while(fscanf(POINTS, "%s", buf) != EOF) 
      // printf("%s \n",buf); 
      //pclose(POINTS); 

      BufferedReader in = new BufferedReader(new FileReader("<filename>")); 

      while ((in = fileReader.readLine()) != null){ 
       System.out.printf("%s \n", buf); 
      } 
      POINTS.close(); 

更新：下面：

現在我已經得到了下面的，這個問題似乎有意義嗎？有兩種不同的C程序，它們根據命令生成文件並執行一些特定的計算。

void run_oconv_and_rtrace() throws IOException{ 
    String line; 
    String cmd = null; 

    //generate octree for this case 
    //============================= 
    //TODO review how the command is generated and what information is required for this analysis 
    cmd = String.format(cmd,"%soconv -f %s %s %s \"%s\" > %s\n","", material_file, BlindRadianceFiles_Combined, geometry_file, sun_rad, octree); 

    /* Use the processbuilder to run an external process (ie. Radiance C program). 
    * process.getOutputStream(): return the standard input of the external program. (ie. Java writes to Process). 
    * process.getInputStream(): return the standard output of the external program. (ie. Jave reads from Process). 
    */ 

    ProcessBuilder builder = new ProcessBuilder(cmd); 
    builder.redirectErrorStream(true);     //adds error stream to inputstream 
    Process process = builder.start(); 

    OutputStream POINTS_FROM_JAVA_TO_C = process.getOutputStream(); 
    InputStream POINTS_FROM_C_TO_JAVA = process.getInputStream(); 

    //BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(POINTS_FROM_JAVA_TO_C)); 
    BufferedReader reader = new BufferedReader(new InputStreamReader(POINTS_FROM_C_TO_JAVA)); 

    //Read output of Radiance: 
    while ((line = reader.readLine()) != null){ 
     System.out.printf("%s \n", buf); 
    } 

    ////////////////////////// 


    // run rtrace and calcualte the shading status for this case 
    //========================================================== 
    //TODO review command 
    cmd = null; 
    cmd = String.format(cmd, "rtrace_dc -ab 0 -h -lr 6 -dt 0 \"%s\" < %s > %s\n",octree,long_sensor_file[BlindGroupIndex],dir_tmp_filename[NumberOfBlindGroupCombinations]); 

    builder = new ProcessBuilder(cmd); 
    builder.redirectErrorStream(true);     //adds error stream to inputstream 
    process = builder.start(); 

    POINTS_FROM_C_TO_JAVA = process.getInputStream(); 
    reader = new BufferedReader(new InputStreamReader(POINTS_FROM_C_TO_JAVA)); 

    //Read output of Radiance: 
    while ((line = reader.readLine()) != null){ 
     System.out.printf("%s \n", buf); 
    } 

    //delete files 
    //HERE WE NEED TO DELETE THE OCTREE FILES CREATED! 

    BlindGroupNumberForThisCombination[NumberOfBlindGroupCombinations]=BlindGroupIndex; 
    NumberOfBlindGroupCombinations++; 
} 

Answer 1

改變這一行

BufferedReader in = new BufferedReader(new FileReader("<filename>")); 

這樣：

BufferedReader in = new BufferedReader(new InputStreamReader(POINTS));