我的程序是接收到数据之后写入文件，数据都接收到了，但是为什么没有写入到文件（图片）呢？这是我的代码
System.out.println("run");

String path2 = android.os.Environment.getExternalStorageDirectory()
.toString()
+ "/EasyCoder" + "/" + name + ".png";
  File file=new File(path2);
  try {
file.createNewFile();
} catch (IOException e1) {
e1.printStackTrace();
}

int length2 = 0;
byte[] buf2 = new byte[1024];
try {
DataOutputStream fileOut = new DataOutputStream(
new BufferedOutputStream(new FileOutputStream(path2)));

while (true) {
int read = 0;
if (in != null) {
read = in.read(buf2);
}
System.out.println(read);
if (read == -1) {
break;
}
fileOut.write(buf2, 0, read);

}
   
fileOut.flush();
fileOut.close();
in.close();

} catch (Exception e) {
e.printStackTrace();
}
我不是太清楚为什么你要用DataOutputStream来做，而且in这个变量也不知道如何获取到的
在我这里用这个DataOutputStream还是可以实现复制图片的，我想如果你那里有问题，可能在in这个变量上面
我的代码如下
Java code
import java.io.*;

public class DataOutputStreamTest {
    public static void main(String[] args){
        System.out.println("run");

        String path1 = "resources/images/thu3.jpg";
        String path2 = "resources/images/thu5.jpg";
        File file=new File(path2);
        try {
            file.createNewFile();
        } catch (IOException e1) {
            e1.printStackTrace();
        }

        int length2 = 0;
        byte[] buf2 = new byte[1024];
        try {
            DataOutputStream fileOut = new DataOutputStream(
                    new BufferedOutputStream(new FileOutputStream(path2)));

            DataInputStream in = new DataInputStream(
                    new BufferedInputStream(new FileInputStream(path1)));
            while (true) {
                int read = 0;
                if (in != null) {
                    read = in.read(buf2);
                }
                System.out.println(read);
                if (read == -1) {
                    break;
                }
                fileOut.write(buf2, 0, read);

            }

            fileOut.flush();
            fileOut.close();
            in.close();

        } catch (Exception e) {
            e.printStackTrace();
        }    }}DataOutputStream 用OutputStream 不就行了