如何根据java中的条件从文件中获取一行 [英] How can I get a line from a file based on a condtion in java
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问题描述
我有一个文件,我正在逐行阅读。例如
package com.java2novice.files;
import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
public class ReadLinesFromFile {
public static void main( String a []){
BufferedReader br = null;
字符串 strLine = ;
尝试 {
br = new BufferedReader( new FileReader( fileName));
while ((strLine = br.readLine())!= null){
System.out.println(strLine);
}
} catch (FileNotFoundException e){
System.err.println( 无法找到文件:fileName);
} catch (IOException e){
System.err.println( 无法读取文件:fileName);
}
}
}
我想从文件中提取一行,如果该行包含Lets C ++。
即如果一行包含Lets C ++,则将整行存储在一个字符串中。
任何人都可以帮我解决这个问题。
提前致谢
解决方案
参见 String.contains(Java Platform SE 7) [ ^ ] 。
你需要的是下面的改变
while ((strLine = br.readLine())!= null ){
System。出跨度> .println(strLine中);
}
TO
< pre lang =C#> while ((strLine = br.readLine())!= null ) {
if (strLine.toLowerCase()。contains( 让C ++ .toLowerCase())
{
System。 out .println(strLine);
}
}
Hi , I have a file which i am reading line by line.for e.g
package com.java2novice.files;
import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
public class ReadLinesFromFile {
public static void main(String a[]){
BufferedReader br = null;
String strLine = "";
try {
br = new BufferedReader( new FileReader("fileName"));
while( (strLine = br.readLine()) != null){
System.out.println(strLine);
}
} catch (FileNotFoundException e) {
System.err.println("Unable to find the file: fileName");
} catch (IOException e) {
System.err.println("Unable to read the file: fileName");
}
}
}
I want to extract a single line from the file , if the line contains "Lets C++".
i.e if a line contains "Lets C++", store the entire line in a string.
Can anyone help me in getting this.
Thanks in advance
解决方案
See String.contains (Java Platform SE 7 )[^].
What you need is change below
while( (strLine = br.readLine()) != null){ System.out.println(strLine); }
TO
while( (strLine = br.readLine()) != null){ if( strLine.toLowerCase().contains("Lets C++".toLowerCase()) { System.out.println(strLine); } }
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