代码实现如下：
import java.io.File;
import java.io.PrintWriter;
import java.util.Scanner; public class FileReplaceKeywords { public static void main(String[] args) throws Exception {
// 检测参数
if (args.length != 4) {
System.out
.println("Usage:java FileReplaceKeywords sourceFile targetFile initWord newWord ");
System.exit(0);
}
String sourceFile = args[0];
String targetFile = args[1];
String initWord = args[2];
String newWord = args[3];
File source = new File(sourceFile);
File target = new File(targetFile);
// 检查文件是否存在
if (!source.exists()) {
System.out.println("-- Sorry,source file：" + sourceFile
+ " can't be found. --");
System.exit(0);
} Scanner input = new Scanner(source);
PrintWriter writer = new PrintWriter(target);
while (input.hasNext()) {
String newStr = input.nextLine().replaceAll(initWord, newWord);
writer.write(newStr + "\n");
}
input.close();
writer.close();
System.out.println("--- finish ----"); } }
=========测试==========
step1:
新建类，命名
FileReplaceKeywords
step2:
当前类路径下增加测试文件 test.txt
how are you
how do you do
I am fine
where are you going now
who are you working for
step3:编译后执行
result:
how are YOU
how do YOU do
I am fine
where are YOU going now
who are YOU working for