Java比较两个文本文件并编写不同的文件

Question

public class TxtCompare
{   
    public static void main(String[] args) throws IOException
    {   
        BufferedReader reader1 = new BufferedReader(new FileReader("x"));
        BufferedReader reader2 = new BufferedReader(new FileReader("x"));
         
        String line1 = reader1.readLine();
        String line2 = reader2.readLine();
         
        boolean areEqual = true;
        int lineNum = 1;
         
        while (line1 != null || line2 != null)
        {
            if(line1 == null || line2 == null)
            {
                areEqual = false;
                break;
            }
            else if(! line1.equalsIgnoreCase(line2))
            {
                areEqual = false;
                break;
            }
            line1 = reader1.readLine();
            line2 = reader2.readLine();
            lineNum++;
        }
         
        if(areEqual)
        {
            System.out.println("Two files have same content.");
        }
        else
        {
            System.out.println("Two files have different content. They differ at line "+lineNum);
             
            System.out.println("File1 has "+line1+" and File2 has "+line2+" at line "+lineNum);

Answer 1

您的代码应该按照预期工作，但可以简化和改进。

循环中的两个if语句具有相同的内容，因此可以连接。这还删除了一个空检查,因为EqualSignoRecase中已经执行了该检查：

if (line1 == null || !line1.equalsIgnoreCase(line2)) {
    areEqual = false;
     break;
}

您可以为这两个读取器使用try-with-resources，并删除显式调用以关闭，因为这是隐式完成的。

try (BufferedReader reader1 = new BufferedReader(new FileReader("file1.txt"));
     BufferedReader reader2 = new BufferedReader(new FileReader("file2.txt"))) {
    // code here
}

try (BufferedReader reader1 = new BufferedReader(new FileReader("file1.txt"));
     BufferedReader reader2 = new BufferedReader(new FileReader("file2.txt"))) {

    int lineNum = 1;
    boolean areEqual = true;
    while (true) {
        String line1 = reader1.readLine();
        String line2 = reader2.readLine();
        if (line1 == null && line2 == null) {
            break;
        } else if (line1 == null || !line1.equalsIgnoreCase(line2)) {
            System.out.println("Two files have different content. They differ at line " + lineNum);
            System.out.println("File1 has " + line1 + " and File2 has " + line2 + " at line " + lineNum);
            areEqual = false;
        }
        lineNum++;
    }

    if (areEqual) {
        System.out.println("Two files have same content.");
    }
}