ByteArrayOutputStream小测试

import java.io.*;

import org.junit.Test;

public class ByteArrayOutputStreamTest {

    @Test
    public void test1() throws Exception {
        //创建文件输入字节流 文件在model下
        FileInputStream fis = new FileInputStream("a.txt");
        //调用方法出入字节流
        String info = readStringFromInputStream(fis);
        System.out.println(info);
    }

    private String readStringFromInputStream(FileInputStream fis) throws IOException {
/*        // 方式一：可能出现乱码
         StringBuilder content = new StringBuilder();
         byte[] buffer = new byte[1024];
         int len;
         while((len = fis.read(buffer)) != -1){
         content.append(new String(buffer));
         }
         return content.toString();*/

/*        // 方式二：BufferedReader
        //创建字符缓冲输入流
        BufferedReader reader = new BufferedReader(new InputStreamReader(fis));
        //创建char数组
        char[] buf = new char[10];
        int len;
        //创建可变字符串
        StringBuilder str = new StringBuilder();
        while ((len = reader.read(buf)) != -1) {
            //每次在末尾添加
//            str.append(new String(buf, 0, len));
            str.append(new String(buf));
        }
        return str.toString();*/

        // 方式三：避免出现乱码
        //创建内存流 字节数组输出流
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        byte[] buffer = new byte[10];
        int len;
        while ((len = fis.read(buffer)) != -1) {
//            baos.write(buffer, 0, len);
            baos.write(buffer);
        }
        return baos.toString();
    }
}