Java - 缓冲区 - 我的代码在阅读时跳过了文本文件的最后一行
Java - Buffer - My Code skips the last Line of a TextFile when reading
im 正在尝试将每行数字的 TextFile 读入 ArrayList。
当我执行以下功能时,它总是跳过最后一个元素。
有人可以帮我吗?因为我在这里没有得到问题,因为它读取直到缓冲区为空,他应该在到达 FileEnd 时停止,对吗?
List<Double> lines = new ArrayList<>();
ByteBuffer buffer = ByteBuffer.allocateDirect(1024);
StringBuilder oneLine = new StringBuilder();
try (SeekableByteChannel byteChannel = Files.newByteChannel(Paths.get(fileName))) {
while (byteChannel.read(buffer) > 0) {
buffer.flip();
for (int i = 0; i < buffer.limit(); i++) {
char c = (char) buffer.get();
if (c == '\r') {
//Skip it
}
if (c == '\n') {
System.out.println(oneLine.toString()); //Test Output to see what he got
lines.add(Double.parseDouble(oneLine.toString().replace(',', '.')));
oneLine.setLength(0);
}
else {
if (c != '\r') {
oneLine.append(c);
}
}
}
buffer.clear();
}
System.out.println("Anzahl zeilen: " + (lines.size()));
System.out.println("Finished");
}
catch (IOException e) {
System.out.println("The File that was defined could not be found");
e.printStackTrace();
}
return lines;
}
每行一个数字的文本文件:
999973
22423
999974
999975
999976
999977
573643
999978
999979
999980
999981
34322
999982
999983
999984
999985
999986
999987
999988
3
67
84,000
7896575543
8.0
100001
9999991
8.0
当您到达文件末尾并且文件末尾没有换行符时,您会将字符添加到 StringBuilder
但永远不会将其附加到列表中。您可以在文本文件末尾添加换行符,也可以在调用 buffer.clear()
.
之前调用 lines.add(...)
im 正在尝试将每行数字的 TextFile 读入 ArrayList。 当我执行以下功能时,它总是跳过最后一个元素。 有人可以帮我吗?因为我在这里没有得到问题,因为它读取直到缓冲区为空,他应该在到达 FileEnd 时停止,对吗?
List<Double> lines = new ArrayList<>();
ByteBuffer buffer = ByteBuffer.allocateDirect(1024);
StringBuilder oneLine = new StringBuilder();
try (SeekableByteChannel byteChannel = Files.newByteChannel(Paths.get(fileName))) {
while (byteChannel.read(buffer) > 0) {
buffer.flip();
for (int i = 0; i < buffer.limit(); i++) {
char c = (char) buffer.get();
if (c == '\r') {
//Skip it
}
if (c == '\n') {
System.out.println(oneLine.toString()); //Test Output to see what he got
lines.add(Double.parseDouble(oneLine.toString().replace(',', '.')));
oneLine.setLength(0);
}
else {
if (c != '\r') {
oneLine.append(c);
}
}
}
buffer.clear();
}
System.out.println("Anzahl zeilen: " + (lines.size()));
System.out.println("Finished");
}
catch (IOException e) {
System.out.println("The File that was defined could not be found");
e.printStackTrace();
}
return lines;
}
每行一个数字的文本文件:
999973
22423
999974
999975
999976
999977
573643
999978
999979
999980
999981
34322
999982
999983
999984
999985
999986
999987
999988
3
67
84,000
7896575543
8.0
100001
9999991
8.0
当您到达文件末尾并且文件末尾没有换行符时,您会将字符添加到 StringBuilder
但永远不会将其附加到列表中。您可以在文本文件末尾添加换行符,也可以在调用 buffer.clear()
.
lines.add(...)