I/O之Writer-Reader

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

import org.junit.Test;

public class RorW {
    // 测试 Reader Writer
    @Test
    public void test1() {

        // ---------------------创建测试文件---------------------
        File file = new File("E:/IO测试/测试.txt");
        if (!file.exists()) {
            file.getParentFile().mkdirs();
            try {
                file.createNewFile();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        // ---------------------测试FileWriter-----------------------
        FileWriter fw = null;
        try {
            fw = new FileWriter(file);
            fw.write("这是测试输出流");
            // fw.write("这是测试输出流覆盖");
            // ==========================================================
            if (fw != null) {// FileWriter声明的引用,必须flush()和close()后才能重新赋值
                try {
                    fw.flush();
                } catch (IOException e) {
                    e.printStackTrace();
                }
                try {
                    fw.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }// FileWriter声明的引用,必须flush()和close()后才能重新赋值
                // ==========================================================
            fw = new FileWriter(file, true);
            fw.write("+这是测试追加输出流");
        } catch (IOException e1) {
            e1.printStackTrace();
        } finally {
            if (fw != null) {
                try {
                    fw.flush();
                } catch (IOException e) {
                    e.printStackTrace();
                }
                try {
                    fw.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }

        // ---------------------测试FileReader---------------------
        FileReader fr = null;
        try {
            fr = new FileReader(file);
            // ============单次只读取一个字符,返回int型编码
            int i = fr.read();
            System.out.println(i);
            System.out.println((char) i);// 将int型编码强制转换字符输出
            // ============
            while ((i = fr.read()) != -1) {// 当返回-1时表示到达文件末尾;
                System.out.print((char) i);
            }
            System.out.println();// 为了输出好看
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            // 关闭资源
            if (fr != null) {
                try {
                    fr.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }

    }

    @Test
    public void test2() {
        try {
            FileReader fr = new FileReader("E:/IO测试/测试.txt");
            char[] cbuf = new char[1024];
            if (fr.ready()) {
                fr.read(cbuf);
                System.out.println(cbuf);
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

}