假设一个文件包含以下几行:
#Do
#not
#use
#these
#lines.
Use
these.
我的目标是只阅读那些不以#
. 如何在 Java 中以最佳方式完成这项工作?
让我们假设您想要累积行(当然您可以对每一行做任何事情)。
String filePath = "somePath\\lines.txt";
// Lines accumulator.
ArrayList<String> filteredLines = new ArrayList<String>();
BufferedReader bufferedReader = null;
try {
bufferedReader = new BufferedReader(new FileReader(filePath));
String line;
while ((line = bufferedReader.readLine()) != null) {
// Line filtering. Please note that empty lines
// will match this criteria!
if (!line.startsWith("#")) {
filteredLines.add(line);
}
}
}
finally {
if (bufferedReader != null)
bufferedReader.close();
}
使用 Java 7 try-with-resources语句:
String filePath = "somePath\\lines.txt";
ArrayList<String> filteredLines = new ArrayList<String>();
try (Reader reader = new FileReader(filePath);
BufferedReader bufferedReader = new BufferedReader(reader)) {
String line;
while ((line = bufferedReader.readLine()) != null) {
if (!line.startsWith("#"))
filteredLines.add(line);
}
}
使用String.startsWith()
方法。在你的情况下,你会使用
if(!myString.startsWith("#"))
{
//some code here
}
BufferedReader.readLine() 返回一个字符串。您可以检查该行是否以#
使用 string.startsWith()开头
FileReader reader = new FileReader("file1.txt");
BufferedReader br = new BufferedReader(reader);
String line="";
while((line=br.readLine())!=null){
if(!line.startsWith("#")){
System.out.println(line);
}
}
}