Question

我有一个输入文件inputfile.txt，后面有3行：

REPLACE_STRING_1 is karthik
REPLACE_STRING_2 is 21
REPLACE_STRING_3 is chennai

我需要用不同的值替换replace_strings并将内容写入新文件。但是使用下面的代码，我最终在新文件中有3组相同的行。我怎样才能解决这个问题？我希望最终输出看起来像这样：

name is karthik
age is 21
city is chennai

这是我的代码：

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

    String ReplaceVar1 = oldtext.replaceAll("REPLACE_STRING_1", "name");                
    String ReplaceVar2 = oldtext.replaceAll("REPLACE_STRING_2", "age");
    String ReplaceVar3 = oldtext.replaceAll("REPLACE_STRING_3", "city");

    // Write updated record to a file
    FileWriter writer = new FileWriter("outputfile.txt");
    writer.write(ReplaceVar1 + ReplaceVar2 + ReplaceVar3);                
    writer.close();                
} catch (IOException ioe) {
    ioe.printStackTrace();
}

我很感激任何帮助。

Answer 1

您应该更改新文本并仅打印最后一个结果。

String result = oldtext.replaceAll("REPLACE_STRING_1", "name")
                       .replaceAll("REPLACE_STRING_2", "age")
                       .replaceAll("REPLACE_STRING_3", "city");

请注意，String是不可变的，replaceAll会返回整个文本，并带有所需的更改。

Answer 2

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


    System.out.println("Running ReplaceText");
    // replace a word in a file
    // REPLACE_STRING_1TENANT_ID REPLACE_STRING_1SOURCE_IP REPLACE_STRING_1USER_NAME REPLACE_STRING_1TARGET_HOSTNAME REPLACE_STRING_1MBODY_TIME
    String newText = oldtext.replaceAll("REPLACE_STRING_1", "name");                
    newText = newText.replaceAll("REPLACE_STRING_2", "age");
    newText = newText.replaceAll("REPLACE_STRING_3", "city");

    // Write updated record to a file
    FileWriter writer = new FileWriter("outputfile.txt");
    writer.write(newText);                
    writer.close();                
} catch (IOException ioe) {
    ioe.printStackTrace();
}

我测试了它，它给了我正确的输出

-MacBook-Pro-2:Desktop john$ cat outputfile.txt 
name is karthik
age is 21
city is chennai

Java：替换文件中的多个字符串并将其写入输出文件

2 个答案: