关于文件!
用程序实现：修改一个目录下的文件及其子目录下的文件的内容。
例如:将code目录下的所有Java源文件中的字符串"frame"替换为"myFrame"!
以下是一个参考例子,但是它仅是用于搜索文件中含有的关键字符，并不能对文件进行修改。
如果那们朋友知道怎样实现这个操作，请帮个忙！非常感谢
[解决办法]
从oldfile读一行 到 strLine
newLine = strLine.replace("frame","myFrame")
将newLine写到 newfile
完了删了oldfile 将newfile重命名为oldfile
[解决办法]
啊,还用到了线程.code下还有没有文件夹?在学校的时候老师叫我做一个给一个路径,然后显示这个路径下的所有文件.
[解决办法]
这段代码写得很不错，用到的全是 JDK 1.5 中的新特性，还用到了
java.util.concurrent 包（这可能是 JDK 1.5 中最深奥的一个
包了）。
有意思，如果要替换的话，除了读文件之外，还需要写文件，下面的
参考以你的代码为基础，仅对 java 文件作操作。
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
public class BlockingQueueTest {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
System.out.print("Enter base directory (e.g. f:/test): ");
String directory = in.nextLine();
System.out.print(" Enter original string (e.g. frame): ");
String keyword = in.nextLine();
System.out.print(" Enter replace with (e.g. MyFrame): ");
String replace = in.nextLine();
final int FILE_QUEUE_SIZE = 10;
final int SEARCH_THREADS = 100;
BlockingQueue <File> queue = new ArrayBlockingQueue <File>(FILE_QUEUE_SIZE);
FileEnumerationTask enumerator = new FileEnumerationTask(queue, new File(directory));
new Thread(enumerator).start();
for (int i = 1; i <= SEARCH_THREADS; i++)
new Thread(new SearchTask(queue, keyword, replace)).start();
}
}
/**
* This task enumerates all files in a directory and its subdirectories.
*/
class FileEnumerationTask implements Runnable {
/**
* Constructs a FileEnumerationTask.
*
* @param queue the blocking queue to which the enumerated files are added
* @param startingDirectory the directory in which to start the enumeration
*/
public FileEnumerationTask(BlockingQueue <File> queue, File startingDirectory) {
this.queue = queue;
this.startingDirectory = startingDirectory;
}
public void run() {
try {
enumerate(startingDirectory);
queue.put(DUMMY);
} catch (InterruptedException e) {
}
}
/**
* Recursively enumerates all files in a given directory and its
* subdirectories
*
* @param directory the directory in which to start
*/
public void enumerate(File directory) throws InterruptedException {
File[] files = directory.listFiles();
for (File file : files) {
if (file.isDirectory())
enumerate(file);
else
queue.put(file);
}
}
public static File DUMMY = new File("");
private BlockingQueue <File> queue;
private File startingDirectory;
}
/**
* This task searches files for a given keyword.
*/
class SearchTask implements Runnable {
/**
* Constructs a SearchTask.
*
* @param queue the queue from which to take files
* @param keyword the keyword to look for
*/
public SearchTask(BlockingQueue <File> queue, String keyword, String replace) {
this.queue = queue;
this.keyword = keyword;
this.replace = replace;
}
public void run() {
try {
boolean done = false;
while (!done) {
File file = queue.take();
if (file == FileEnumerationTask.DUMMY) {
queue.put(file);
done = true;
} else
replace(file);
}
} catch (IOException e) {
e.printStackTrace();
} catch (InterruptedException e) {
}
}
/**
* Searches a file for a given keyword and prints all matching lines.
*
* @param file the file to search
*/
public void search(File file) throws IOException {
Scanner in = new Scanner(new FileInputStream(file));
int lineNumber = 0;
while (in.hasNextLine()) {
lineNumber++;
String line = in.nextLine();
if (line.contains(keyword))
System.out.printf("%s:%d:%s%n", file.getPath(), lineNumber,
line);
}
in.close();
}
public void replace(File file) throws IOException {
// Replacing in .java file only.
if(!file.getName().toLowerCase().endsWith(".java")) {
return;
}
Scanner in = new Scanner(new FileInputStream(file));
boolean isRewrite = false;
List <String> list = new ArrayList <String>();
int k = 0;
while (in.hasNextLine()) {
String line = in.nextLine();
if(line.contains(keyword)) {
line = line.replace(keyword, replace);
isRewrite = true;
}
list.add(line);
k++;
}
in.close();
if(isRewrite) {
writeFile(file, list);
}
list.clear();
System.out.println(file.getName() + " " + k);
}
private void writeFile(File file, List <String> list) throws IOException {
BufferedWriter bw = new BufferedWriter(new FileWriter(file));
String line = System.getProperty("line.separator");
for(String str : list) {
bw.write(str + line);
}
bw.close();
}
private BlockingQueue <File> queue;
private String keyword;
private String replace;
}
