JAVA 文件输入/输出流

输入流：FileInputStream与FileReader
输出流：FileOutputStream与FileWriter

package cn.com.file;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

/**
 * FileInputStream类与FileOutputStream类<br>
 * 文件读与写
 * @author wutz
 *
 */
public class FileTest {

    public static void main(String[] args) {
        //1.先往文件中写入数据
        try {
            FileOutputStream out = new FileOutputStream(new File("C:/Users/wutz/Desktop/j2se/resource/test.txt"));
            byte[] bt = "测试写入文件".getBytes();
            out.write(bt);
            out.close();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

        //2.从文件中读取数据到控制台
        try {
            FileInputStream in = new FileInputStream(new File("C:/Users/wutz/Desktop/j2se/resource/test.txt"));
            byte[] bt1 = new byte[1024]; 
            int lenth = in.read(bt1);
            System.out.println("文件中的信息是："+ new String(bt1,0,lenth));
            in.close();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

    }
}

package cn.com.file;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;

/**
 * FileWriter类与FileReader类<br>
 * 文件读与写（处理字符流）
 * @author wutz
 *
 */
public class FileTest {

    public static void main(String[] args) {
        //1.先往文件中写入数据
        try {
            FileWriter out = new FileWriter(new File("C:/Users/wutz/Desktop/j2se/resource/test.txt"));
            String s = new String("测试FileWriter"
                    + "123阿萨德");
            out.write(s);
            out.close();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

        //2.从文件中读取数据到控制台
        try {
            FileReader in = new FileReader(new File("C:/Users/wutz/Desktop/j2se/resource/test.txt"));
            char[] ch = new char[1024];
            int lenth = in.read(ch);
            System.out.println("文件中的信息是："+ new String(ch,0,lenth));
            in.close();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}