使用scanner从文本文件中读取字符串然后打印出来

Question

我有一个文本文件，其中包含字符串 - "!- =========== ALL OBJECTS IN CLASS: FENESTRATIONSURFACE:DETAILED ==========="，如下面的代码所示。如果文本文件包含此字符串，我需要从文本文件中读取它，然后再次打印出来。问题是我无法弄清楚为什么我的代码不打印它。

任何帮助将不胜感激！

public class Main {

    public static void main(String[] args) throws FileNotFoundException {

        File file = new File("C:/Users/Anton/Pictures/1 x geotransform0.5m shading.txt");

        Scanner scan = new Scanner(file);

            while(scan.hasNext()){
                String str = scan.next();

                if(str == "!-   ===========  ALL OBJECTS IN CLASS: FENESTRATIONSURFACE:DETAILED ==========="){
                    System.out.print(str);
                }
            }
            scan.close();
        }   
}

Answer 1

使用下面的代码，扫描仪接下来只给出一个单词使用nextLine而不是读取整行...

Scanner scan = new Scanner(file);
            String str1 = scan.nextLine();

                if(str1.equals("!-   ===========  ALL OBJECTS IN CLASS: FENESTRATIONSURFACE:DETAILED ==========="))
                    System.out.println(str1);
                scan.close();

Answer 2

使用此

if(str.equals("!-   ===========  ALL OBJECTS IN CLASS: FENESTRATIONSURFACE:DETAILED ===========")){
            System.out.print(str);
        }

而不是

if(str == "!-   ===========  ALL OBJECTS IN CLASS: FENESTRATIONSURFACE:DETAILED ==========="){
            System.out.print(str);
        }