搜索文本文件java

Searching through a text file java

提问by

So I am trying to search through a text file and if the user input is found, it returns the entire sentence including white spaces.But apparently I only get the first string and nothing pass the first string in the sentence. For example if i have a text file called "data.txt" and the contents in the first line is " I am a legend". after user enters "I am a legend" the output after the file is searched is "I". Any help would be appreciated.

所以我试图搜索一个文本文件，如果找到用户输入，它会返回包括空格在内的整个句子。但显然我只得到第一个字符串，而没有传递句子中的第一个字符串。例如，如果我有一个名为“data.txt”的文本文件，第一行的内容是“我是传奇”。用户输入“我是传奇”后，搜索文件后的输出为“我”。任何帮助，将不胜感激。

 public static void Findstr() { // This function searches the text for the    string

    File file = new File("data.txt");

     Scanner kb = new Scanner(System.in);

    System.out.println(" enter the content you looking for");
    String name = kb.next();
    Scanner scanner;
    try {
        scanner = new Scanner(file).useDelimiter( ",");

        while (scanner.hasNext()) {
            final String lineFromFile = scanner.nextLine();
            if (lineFromFile.contains(name)) {
                // a match!
                System.out.println("I found " + name);
                break;
            }
        }
    } catch (IOException e) {
        System.out.println(" cannot write to file " + file.toString());
    }

采纳答案by takeradi

package com.example;

import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;

public class FileSearch {

    public void parseFile(String fileName,String searchStr) throws FileNotFoundException{
        Scanner scan = new Scanner(new File(fileName));
        while(scan.hasNext()){
            String line = scan.nextLine().toLowerCase().toString();
            if(line.contains(searchStr)){
                System.out.println(line);
            }
        }
    }


    public static void main(String[] args) throws FileNotFoundException{
        FileSearch fileSearch = new FileSearch();
        fileSearch.parseFile("src/main/resources/test.txt", "am");
    }

}


test.txt contains:
I am a legend
Hello World
I am Ironman

Output:
i am a legend
i am ironman

The above code does case insensitive search. You should use nextLine() to get the complete line. next() breaks on whitespaces.

上面的代码不区分大小写搜索。您应该使用 nextLine() 来获取完整的行。next() 在空格处中断。

Reference: http://docs.oracle.com/javase/7/docs/api/java/util/Scanner.html#next()

参考：http: //docs.oracle.com/javase/7/docs/api/java/util/Scanner.html#next()

回答by

Scanner.next();returns the next caracter instead use Scanner.readLine();

Scanner.next();返回下一个字符而不是使用 Scanner.readLine();

Edit: Belive Scanners use .nextLine();not .readLine();

编辑：Belive 扫描仪.nextLine();不使用.readLine();

回答by SaurabhJinturkar

When you are scanning your input..

当您扫描输入时..

Scanner kb = new Scanner(System.in);
System.out.println(" enter the content you looking for");
String name = kb.next();

You are accepting only one token. You should accept whole line to be searched as your token using kb.nextLine()

您只接受一种令牌。您应该接受整行作为您的令牌进行搜索kb.nextLine()