Question

我想删除某些日志条目以解析文件。但是，在运行BufferedReader和其他导入的函数和库时，我使用.replaceAll方法运行的代码中出现错误。如何删除＆＃34; rule_uid：{C1336766-9489-4049-9817-50584D83A245};＆＃34;没有导致错误？

日志文件：

        var s = document.getElementById('t');
        var g = s.childNodes[1];
        g.childNodes[1].remove();
        var foreign = document.createElementNS('http://www.w3.org/2000/svg',"foreignObject");
        foreign.setAttribute('width', 500);
        foreign.setAttribute('height', 150);
        var t = document.createTextNode("This is a paragraph.");
        foreign.appendChild(t);
        g.appendChild(foreign);

错误：

Jan 1 22:54:17 drop   %LOGSOURCE% >eth1 rule: 7; rule_uid: {C1336766-9489-4049-9817-50584D83A245};
Jan 1 22:54:22 drop   %LOGSOURCE% >eth1 rule: 7; rule_uid: {C1336766-9489-4049-9817-50584D83A245};
Jan 1 22:54:23 drop   %LOGSOURCE% >eth1 rule: 7; rule_uid: {C1336766-9489-4049-9817-50584D83A245};
Jan 1 22:54:41 drop   %LOGSOURCE% >eth1 rule: 7; rule_uid: {C1336766-9489-4049-9817-50584D83A245};

代码：

"Exception in thread "main" java.util.regex.PatternSyntaxException: Illegal repetition near index 9
rule_uid: {C1336766-9489-4049-9817-50584D83A245};" (which is at the .replaceAll() method for rule_uid column)

Answer 1

在第二次调用replaceAll()时，输入字符串中有特殊字符，这些字符被解释为正则表达式语法的一部分，而不是要替换的纯文本。一旦我在IntelliJ中转义了这些特殊字符，编译器错误便消失了。

改变这个：

String newtext = oldtext.replaceAll("%LOGSOURCE% >eth1 rule: 7;", "");
String newtext1 = oldtext.replaceAll("rule_uid: {C1336766-9489-4049-9817-50584D83A245};", "");

对此：

String newtext = oldtext.replaceAll("%LOGSOURCE% >eth1 rule: 7;", "");
String newtext1 = oldtext.replaceAll("rule_uid: \\{C1336766-9489-4049-9817-50584D83A245\\};", "");

我所做的只是用两个前导反斜杠来逃避花括号，例如： \\{

<强>更新

您的代码中还有其他一些逻辑问题。以下是我建议您使用的完整代码：

try {
    File file = new File("filename");
    BufferedReader reader = new BufferedReader(new FileReader(file));
    String line = "", oldtext = "";
    while ((line = reader.readLine()) != null) {
        oldtext += line + "\r\n";
    }
    reader.close();

    // replace a word in a file
    oldtext = oldtext.replaceAll("%LOGSOURCE% >eth1 rule: 7;", "");
    oldtext = oldtext.replaceAll("rule_uid: \\{C1336766-9489-4049-9817-50584D83A245\\};", "");

    FileWriter writer = new FileWriter("newfilename");

    // the entire file is contained within the String 'oldtext'
    // you only need one write operation to output it
    writer.write(oldtext);
    writer.close();
} catch (IOException ioe) {
    ioe.printStackTrace();
}

如何从.log文件中删除某些列/元素？

1 个答案: