为什么 Java 应用程序在处理 x 个文件后崩溃？
Why does Java app crash after processing x number of files?
我只是在万不得已的时候问这个问题。我被难住了。
我编写了一个执行非常简单的图像处理的小应用程序。它是使用 JDK 1.8 制作的，用 Netbeans 8.0.1 编写，在 Debian Linux.
上是 运行
应用程序通过进程构建器调用 'streamer' 网络摄像头程序，以用户设置的特定帧速率捕获大量单个帧。一旦开始捕获，它就会开始将帧转换为 RGB 值并检查是否有任何像素高于用户定义的阈值。如果没有像素超过此阈值，它只会删除该帧。如果有任何像素超过它，它会将框架移动到不同的文件夹以供用户检查。这一切都很好。它跟上什至相对较高的帧率，并按预期选择合适的帧。但是，当处理的帧数达到 1500 左右（对于较低的帧率或更少）时，程序会冻结。我已经尝试在命令行手动向 streamer 发出命令，它似乎完全能够生成所需数量的流媒体，所以我不得不假设问题出在我的编码上。图片很小 (320x240)。我是否以某种方式最大化可用内存（我没有收到任何错误，只是冻结）。
这个程序的目的是检测宇宙射线对 CMOS 传感器的影响，这是朋友论文的一部分。如果我不能让它可靠地工作，那可怜的孩子将不得不手动检查录像！
代码附在下面。抱歉代码太长了，但由于所有代码都相当重要，所以我不想省略任何内容。
package cosmicraysiii;
import java.io.File;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.JOptionPane;
public class CosmicRaysIII {
public static int dark = 0;//Dark current determined by averaging
public static int tol = 0;//Tolerance set by user
public static int frames = 0;//Total number of frames set by user
public static int runs = 0;
public static int rate = 0;//Framerate set by user
public static int time = 0;//Total time calculated
public static String zeros = "";
public static int ready = 0;
public static void main(String[] args) throws IOException, InterruptedException {
//Get directory ID from user
String id = JOptionPane.showInputDialog("Enter a folder name for detections (no ., in name):");
//Get dark current
Dark d = new Dark();
dark = d.getCurrent();
//Get tolerance from user, will be added to dark current.
String t = JOptionPane.showInputDialog("Dark Current = " + dark + "/255\n"
+ "Enter a tolerance (integer values only).\n "
+ "This will be added to the dark current:");
tol = Integer.parseInt(t) + dark;
//Get number of frames from user
String fs = JOptionPane.showInputDialog("Enter the total number of frames required (Mulitples of 500 only):");
frames = Integer.parseInt(fs);
runs = frames / 500;
//Get framerate from user
String r = JOptionPane.showInputDialog("Enter the framerate required:");
rate = Integer.parseInt(r);
//Determine duration
time = (int) Math.round(frames / rate);
//Provide summary for user and request permission to continue
int secs = time % 60;
int mins = (time - secs) / 60;
int hrs = (mins - (mins % 60)) / 60;
if (hrs >= 1) {
mins = mins % 60;
}
String theMessage = "The following parameters have been set:\n"
+ "Tolerance (including dark current): " + tol + "\n"
+ "Frames: " + frames + "\n"
+ "Frame rate: " + rate + " fps\n"
+ "Total capture time: " + time + " sec\n"
+ " " + hrs + " h " + mins + " m " + secs + " s\n"
+ "\n"
+ "Would you like to proceed?";
int result = JOptionPane.showConfirmDialog(null, theMessage, "Continue?", JOptionPane.OK_CANCEL_OPTION);
if (result == 2) {
System.exit(0);
}
//Create directory for data acquisition
ProcessBuilder pb1 = new ProcessBuilder("mkdir", "data");
pb1.start();
//Establish array of filenames
String[] filenames = new String[frames];
//Fill filenames array with filenames
//Taking into consideration that the filename
//will have a varying number of zeros appended
//before the frame number, dependent on the
//order of the frame number
for (int i = 0; i < frames; i++) {
if (i < 10) {
zeros = "00000000";
} else if (i >= 10 && i < 100) {
zeros = "0000000";
} else if (i >= 100 && i < 1000) {
zeros = "000000";
} else if (i >= 1000 && i < 10000) {
zeros = "00000";
} else if (i >= 10000 && i < 100000) {
zeros = "0000";
} else if (i >= 100000 && i < 1000000) {
zeros = "000";
} else if (i >= 1000000 && i < 10000000) {
zeros = "00";
} else if (i >= 10000000 && i < 100000000) {
zeros = "0";
} else {
zeros = "";
}
filenames[i] = "./data/frame" + zeros + i + ".ppm";
}
//Begin data acquisition
new Thread(new Runnable() {
public void run() {
try {
//Capture images
ProcessBuilder pb2 = new ProcessBuilder("streamer", "-t", Integer.toString(frames), "-r", Integer.toString(rate), "-p", "0", "-o", "./data/frame000000000.ppm");
Process p = pb2.start();
p.waitFor();
ready = 1;
} catch (IOException | InterruptedException ex) {
Logger.getLogger(CosmicRaysIII.class.getName()).log(Level.SEVERE, null, ex);
}
}
}).start();
//Sleep to allow some image capture to prevent thread disordering
Thread.sleep(3000);
//Check array size
System.out.println("Array size: " + filenames.length);
//Conduct image analysis
new Thread(new Runnable() {
public void run() {
int done = 0;
int donea = 0;
while (ready == 0) {
for (int i = 0; i < frames; i++) {
File f = new File(filenames[i]);
if (f.exists() && !filenames[i].equals("")) {//Check file still exists
try {
//Perform analysis steps
Analysis a = new Analysis();
//STEP 1: Convert file from P6 to P3
String newfile = a.convert(filenames[i], zeros, i);
//STEP 2: Read file
a.read(newfile, tol, i, id);
filenames[i] = "";
done++;
} catch (IOException ex) {
Logger.getLogger(CosmicRaysIII.class.getName()).log(Level.SEVERE, null, ex);
}
}
if (done > donea) {
System.out.println(done + " files processed");
donea = done;
}
}
}
}
}).start();
}
}
则Analyse.javaclass如下：
package cosmicraysiii;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
public class Analysis {
public String convert(String ofile, String zeros, int number) throws IOException {
//Create new file name
String nfile = "./proc/frame" + zeros + number + ".ppm";
//Ensure process directory exists
ProcessBuilder mkdir = new ProcessBuilder("mkdir", "proc");
mkdir.start();
//Convert file to P3 PPM (RGB format) and move to process folder
ProcessBuilder convert = new ProcessBuilder("convert", ofile, "-compress", "none", nfile);
convert.start();
//Delete original file
ProcessBuilder del = new ProcessBuilder("sudo", "rm", ofile);
del.start();
//Return new filename
return nfile;
}
public void read(String filename, int tol, int ix, String id) throws FileNotFoundException, IOException {
int move = 0;
//Make directory for hits
ProcessBuilder mkdir = new ProcessBuilder("mkdir", "hits" + id);
mkdir.start();
//Open reader to read file
File f = new File(filename);
if (f.exists()) {
BufferedReader br = new BufferedReader(new FileReader(filename));
String line;
//To eliminate header
int x = 0;
//Iterate through text to find abnormal pixels
while ((line = br.readLine()) != null) {
x++;
String[] pixrgb = line.split("\ ");
//Iterate through pixels on each line
for (int i = 0; i < pixrgb.length; i++) {
if (x >= 4) {//Eliminate header
//Check each pixel value
try {
int pixval = Integer.parseInt(pixrgb[i]);
if (pixval > tol) {
move = 1;
break;
}
} catch (NumberFormatException ne) {
}
}
}
}
if (move == 1) {
//Move file to hits folder
ProcessBuilder pb3 = new ProcessBuilder("sudo", "cp", filename, "./hits" + id + "/detection" + ix + ".ppm");
pb3.start();
//Delete original file
ProcessBuilder del = new ProcessBuilder("sudo", "rm", filename);
del.start();
}
}
//Delete original file
ProcessBuilder del = new ProcessBuilder("sudo", "rm", filename);
del.start();
}
}
我很感激要发布的代码太长了。非常感谢您提供的任何帮助。
G
好的，我已经通过彻底检查分析过程解决了这个问题。首先，我没有将图像转换为 P3 .ppm 文件，而是使用 BufferedReader 直接检查图像中的像素。然后，我停止反复循环文件列表。相反，调用 Analysis() 的循环仅 运行 遍历文件名列表一次。如果它遇到一个尚不存在的文件，它会执行 Thread.sleep(500) 然后再试一次。我现在已经成功地 运行 一批 50,000 帧而没有发生任何事故，并且由于改进的过程，现在内存消耗少了很多。只是想我应该把这个答案放在这里以防万一有人遇到它。如果有人需要，我可以 post 编码。
我只是在万不得已的时候问这个问题。我被难住了。
我编写了一个执行非常简单的图像处理的小应用程序。它是使用 JDK 1.8 制作的，用 Netbeans 8.0.1 编写，在 Debian Linux.
上是 运行应用程序通过进程构建器调用 'streamer' 网络摄像头程序，以用户设置的特定帧速率捕获大量单个帧。一旦开始捕获，它就会开始将帧转换为 RGB 值并检查是否有任何像素高于用户定义的阈值。如果没有像素超过此阈值，它只会删除该帧。如果有任何像素超过它，它会将框架移动到不同的文件夹以供用户检查。这一切都很好。它跟上什至相对较高的帧率，并按预期选择合适的帧。但是，当处理的帧数达到 1500 左右（对于较低的帧率或更少）时，程序会冻结。我已经尝试在命令行手动向 streamer 发出命令，它似乎完全能够生成所需数量的流媒体，所以我不得不假设问题出在我的编码上。图片很小 (320x240)。我是否以某种方式最大化可用内存（我没有收到任何错误，只是冻结）。
这个程序的目的是检测宇宙射线对 CMOS 传感器的影响，这是朋友论文的一部分。如果我不能让它可靠地工作，那可怜的孩子将不得不手动检查录像！
代码附在下面。抱歉代码太长了，但由于所有代码都相当重要，所以我不想省略任何内容。
package cosmicraysiii;
import java.io.File;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.JOptionPane;
public class CosmicRaysIII {
public static int dark = 0;//Dark current determined by averaging
public static int tol = 0;//Tolerance set by user
public static int frames = 0;//Total number of frames set by user
public static int runs = 0;
public static int rate = 0;//Framerate set by user
public static int time = 0;//Total time calculated
public static String zeros = "";
public static int ready = 0;
public static void main(String[] args) throws IOException, InterruptedException {
//Get directory ID from user
String id = JOptionPane.showInputDialog("Enter a folder name for detections (no ., in name):");
//Get dark current
Dark d = new Dark();
dark = d.getCurrent();
//Get tolerance from user, will be added to dark current.
String t = JOptionPane.showInputDialog("Dark Current = " + dark + "/255\n"
+ "Enter a tolerance (integer values only).\n "
+ "This will be added to the dark current:");
tol = Integer.parseInt(t) + dark;
//Get number of frames from user
String fs = JOptionPane.showInputDialog("Enter the total number of frames required (Mulitples of 500 only):");
frames = Integer.parseInt(fs);
runs = frames / 500;
//Get framerate from user
String r = JOptionPane.showInputDialog("Enter the framerate required:");
rate = Integer.parseInt(r);
//Determine duration
time = (int) Math.round(frames / rate);
//Provide summary for user and request permission to continue
int secs = time % 60;
int mins = (time - secs) / 60;
int hrs = (mins - (mins % 60)) / 60;
if (hrs >= 1) {
mins = mins % 60;
}
String theMessage = "The following parameters have been set:\n"
+ "Tolerance (including dark current): " + tol + "\n"
+ "Frames: " + frames + "\n"
+ "Frame rate: " + rate + " fps\n"
+ "Total capture time: " + time + " sec\n"
+ " " + hrs + " h " + mins + " m " + secs + " s\n"
+ "\n"
+ "Would you like to proceed?";
int result = JOptionPane.showConfirmDialog(null, theMessage, "Continue?", JOptionPane.OK_CANCEL_OPTION);
if (result == 2) {
System.exit(0);
}
//Create directory for data acquisition
ProcessBuilder pb1 = new ProcessBuilder("mkdir", "data");
pb1.start();
//Establish array of filenames
String[] filenames = new String[frames];
//Fill filenames array with filenames
//Taking into consideration that the filename
//will have a varying number of zeros appended
//before the frame number, dependent on the
//order of the frame number
for (int i = 0; i < frames; i++) {
if (i < 10) {
zeros = "00000000";
} else if (i >= 10 && i < 100) {
zeros = "0000000";
} else if (i >= 100 && i < 1000) {
zeros = "000000";
} else if (i >= 1000 && i < 10000) {
zeros = "00000";
} else if (i >= 10000 && i < 100000) {
zeros = "0000";
} else if (i >= 100000 && i < 1000000) {
zeros = "000";
} else if (i >= 1000000 && i < 10000000) {
zeros = "00";
} else if (i >= 10000000 && i < 100000000) {
zeros = "0";
} else {
zeros = "";
}
filenames[i] = "./data/frame" + zeros + i + ".ppm";
}
//Begin data acquisition
new Thread(new Runnable() {
public void run() {
try {
//Capture images
ProcessBuilder pb2 = new ProcessBuilder("streamer", "-t", Integer.toString(frames), "-r", Integer.toString(rate), "-p", "0", "-o", "./data/frame000000000.ppm");
Process p = pb2.start();
p.waitFor();
ready = 1;
} catch (IOException | InterruptedException ex) {
Logger.getLogger(CosmicRaysIII.class.getName()).log(Level.SEVERE, null, ex);
}
}
}).start();
//Sleep to allow some image capture to prevent thread disordering
Thread.sleep(3000);
//Check array size
System.out.println("Array size: " + filenames.length);
//Conduct image analysis
new Thread(new Runnable() {
public void run() {
int done = 0;
int donea = 0;
while (ready == 0) {
for (int i = 0; i < frames; i++) {
File f = new File(filenames[i]);
if (f.exists() && !filenames[i].equals("")) {//Check file still exists
try {
//Perform analysis steps
Analysis a = new Analysis();
//STEP 1: Convert file from P6 to P3
String newfile = a.convert(filenames[i], zeros, i);
//STEP 2: Read file
a.read(newfile, tol, i, id);
filenames[i] = "";
done++;
} catch (IOException ex) {
Logger.getLogger(CosmicRaysIII.class.getName()).log(Level.SEVERE, null, ex);
}
}
if (done > donea) {
System.out.println(done + " files processed");
donea = done;
}
}
}
}
}).start();
}
}
则Analyse.javaclass如下：
package cosmicraysiii;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
public class Analysis {
public String convert(String ofile, String zeros, int number) throws IOException {
//Create new file name
String nfile = "./proc/frame" + zeros + number + ".ppm";
//Ensure process directory exists
ProcessBuilder mkdir = new ProcessBuilder("mkdir", "proc");
mkdir.start();
//Convert file to P3 PPM (RGB format) and move to process folder
ProcessBuilder convert = new ProcessBuilder("convert", ofile, "-compress", "none", nfile);
convert.start();
//Delete original file
ProcessBuilder del = new ProcessBuilder("sudo", "rm", ofile);
del.start();
//Return new filename
return nfile;
}
public void read(String filename, int tol, int ix, String id) throws FileNotFoundException, IOException {
int move = 0;
//Make directory for hits
ProcessBuilder mkdir = new ProcessBuilder("mkdir", "hits" + id);
mkdir.start();
//Open reader to read file
File f = new File(filename);
if (f.exists()) {
BufferedReader br = new BufferedReader(new FileReader(filename));
String line;
//To eliminate header
int x = 0;
//Iterate through text to find abnormal pixels
while ((line = br.readLine()) != null) {
x++;
String[] pixrgb = line.split("\ ");
//Iterate through pixels on each line
for (int i = 0; i < pixrgb.length; i++) {
if (x >= 4) {//Eliminate header
//Check each pixel value
try {
int pixval = Integer.parseInt(pixrgb[i]);
if (pixval > tol) {
move = 1;
break;
}
} catch (NumberFormatException ne) {
}
}
}
}
if (move == 1) {
//Move file to hits folder
ProcessBuilder pb3 = new ProcessBuilder("sudo", "cp", filename, "./hits" + id + "/detection" + ix + ".ppm");
pb3.start();
//Delete original file
ProcessBuilder del = new ProcessBuilder("sudo", "rm", filename);
del.start();
}
}
//Delete original file
ProcessBuilder del = new ProcessBuilder("sudo", "rm", filename);
del.start();
}
}
我很感激要发布的代码太长了。非常感谢您提供的任何帮助。
G
好的，我已经通过彻底检查分析过程解决了这个问题。首先，我没有将图像转换为 P3 .ppm 文件，而是使用 BufferedReader 直接检查图像中的像素。然后，我停止反复循环文件列表。相反，调用 Analysis() 的循环仅 运行 遍历文件名列表一次。如果它遇到一个尚不存在的文件，它会执行 Thread.sleep(500) 然后再试一次。我现在已经成功地 运行 一批 50,000 帧而没有发生任何事故，并且由于改进的过程，现在内存消耗少了很多。只是想我应该把这个答案放在这里以防万一有人遇到它。如果有人需要，我可以 post 编码。