public BufferedWriter(Writer out)

public BufferedWriter(Writer out,int sz)

public void close() throws IOException

public void flush() throws IOException

public void newLine() throws IOException

public void write(char[] cbuf,int off,int len) throws IOException

public void write(int c) throws IOException

public void write(String s,int off,int len) throws IOException

package java19;

import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;

/**
 * 2017/10/12
 * 说明：
 */
public class BufferedWriterDemo {
    public static void main(String[] args) throws IOException {
        BufferedWriter bw = new BufferedWriter(new FileWriter("bw.txt"));

        bw.write("abcd");

        bw.flush();

        bw.close();

    }
}