io中的AutoCloseable，Closeable和Flushable接口

AutoCloseable是在java.lang中的（1.7才有的）

Closeable（1.5才有的）接口继承了AutoCloseable接口

public void close()

关闭此流并释放与此流关联的所有系统资源。

继承Closeable接口，使代码更简洁，更清晰

当try代码快结束时，资源（在此时流）会被自动关闭

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;

public class t {
private static BufferedReader reader;

public static void main(String[] args) {
try {
reader = new BufferedReader(new InputStreamReader(new FileInputStream(new File("a"))));
System.out.println(reader.readLine());
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
reader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}

import java.io.BufferedReader;
import java.io.Closeable;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;

public class t implements Closeable {
private static BufferedReader reader;

public static void main(String[] args) {
try {
reader = new BufferedReader(new InputStreamReader(new FileInputStream(new File("a"))));
System.out.println(reader.readLine());
} catch (IOException e) {
e.printStackTrace();
}
}

@Override
public void close() throws IOException {
reader.close();
}

}
flushable相同用法