bytearrayinputstream read

`ByteArrayInputStream`是Java中的一个类，它允许从内存中的字节数组中读取数据。其`read()`方法从输入流中读取一个字节，并将其作为一个整数（0~255）返回。如果到达流的末尾，则返回-1。如果您想要读取多个字节，则可以使用`read(byte[] b, int off, int len)`方法，该方法读取最多`len`个字节到给定字节数组`b`中，开始于偏移量`off`的位置。成功读取的字节数将返回。

相关问题

ByteArrayInputStream read() 方法 返回 byte

是的，Java中的ByteArrayInputStream类的read()方法会从字节数组中读取一个字节，并将其作为一个int类型的值返回，但实际上这个int类型的值只有低8位有效，即返回的是一个byte类型的值。如果读取到了流的结尾，则返回-1。可以使用Java中的类型转换将int类型的返回值转换为byte类型。例如：

ByteArrayInputStream bis = new ByteArrayInputStream(new byte[]{1,2,3});
int b = bis.read(); // 读取第一个字节，返回1
byte bb = (byte)b; // 将int类型的返回值转换为byte类型

ByteArrayInputStream

ByteArrayInputStream is a class in Java that reads bytes from a byte array. It allows you to read a byte array as an input stream. The data is read from the byte array in a sequential manner. This class is useful when you have a byte array that you want to read as an input stream.

The constructor of ByteArrayInputStream takes a byte array as an argument. The class has several methods to read the data from the byte array. For example, you can use the read() method to read a single byte from the input stream, or the read(byte[] b, int off, int len) method to read a specified number of bytes into a byte array.

Here is an example of using ByteArrayInputStream:

byte[] bytes = {1, 2, 3, 4, 5};
ByteArrayInputStream inputStream = new ByteArrayInputStream(bytes);

int data = inputStream.read();
while (data != -1) {
    System.out.print(data + " ");
    data = inputStream.read();
}

This code creates a byte array with the values 1, 2, 3, 4, and 5. Then it creates a new ByteArrayInputStream object with the byte array as the input. The code then reads the data from the input stream using the read() method and prints it to the console. The output of this code would be:

1 2 3 4 5