JDK1.7 NIO.2 读写遍历文件树

使用jdk7 nio.2遍历文件夹里所有文件

首先需要写FileHandler类，继承SimpleFileVisitor<Path>

根据需要重写SimpleFileVisitor里面的方法

比如，访问文件前做些什么，访问文件时做些什么，访问后做些什么

例子中的这行就是遍历每个文件时做的事情，打印一下文件的路径

System.out.println("Visiting:" + path);//do some thing

然后通过Files.walkFileTree遍历headDir这个目录下的所有文件

Files.walkFileTree(headDir, this);

完整的例子如下：

import java.io.IOException;
import java.nio.file.FileVisitResult;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.SimpleFileVisitor;
import java.nio.file.attribute.BasicFileAttributes;
import java.util.Objects;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

@Service("fileHandler")
public class FileHandler extends SimpleFileVisitor<Path> {

	private static final Logger logger = LogManager.getLogger(FileHandler.class);
	
	public void handleMultipleFiles(String path) {
		Path headDir = Paths.get(path);
		try {
			Files.walkFileTree(headDir, this);
		} catch (IOException e) {
			logger.info("WalkFileTree Failed:", e);
		}
	}

	@Override
	public FileVisitResult visitFile(Path path, BasicFileAttributes attrs) throws IOException {
		Objects.requireNonNull(path);
		Objects.requireNonNull(attrs);
		System.out.println("Visiting:" + path);//do some thing
		return FileVisitResult.CONTINUE;
	}
	
}

测试类:

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = AppContext.class)
public class TestVisit {
	
	@Autowired
	private FileHandler fileHandler;

	@Test
	public void test() {
		fileHandler.handleMultipleFiles("C:/Mapper");
	}

}

Spring注解的配置：AppContext.class

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Profile;

@Configuration
@Profile(value = { "default" })
@ComponentScan(basePackages = "com.demo")
public class AppContext {
}

总结：

NIO.2读写文件和遍历文件树还是很方便的

除了读写，还有更高级的文件权限管理功能，文件修改的监控等功能等等

对文件的目录操作工具

import java.nio.file.Path;
import java.nio.file.Paths;

Path filePath = Paths.get("/test");
System.out.println(filePath);
System.out.println(filePath.resolve("pretty.json"));
System.out.println(filePath.resolveSibling("pretty2.json"));
System.out.println(filePath.toAbsolutePath());
System.out.println(filePath.getParent());

对文件的操作工具

import java.nio.file.Files;

Files.readAllBytes(path);
Files.write(path, bytes);
Files.copy(source, target);
Files.delete(path);
Files.createDirectory(dir);
Files.createFile(path);
Files.walkFileTree(start, visitor);

以上

JDK1.7 NIO.2 读写遍历文件树

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