将InputStream(Image)转换为ByteArrayInputStream

时间:2010-08-16 18:08:25

标签: java image inputstream

不确定我应该怎么做。任何帮助将不胜感激

3 个答案:

答案 0 :(得分:24)

从输入流中读取并写入ByteArrayOutputStream,然后调用其toByteArray()以获取字节数组。

在字节数组周围创建ByteArrayInputStream以从中读取。

这是一个快速测试:

import java.io.*;

public class Test {


       public static void main(String[] arg) throws Throwable {
          File f = new File(arg[0]);
          InputStream in = new FileInputStream(f);

          byte[] buff = new byte[8000];

          int bytesRead = 0;

          ByteArrayOutputStream bao = new ByteArrayOutputStream();

          while((bytesRead = in.read(buff)) != -1) {
             bao.write(buff, 0, bytesRead);
          }

          byte[] data = bao.toByteArray();

          ByteArrayInputStream bin = new ByteArrayInputStream(data);
          System.out.println(bin.available());
       }
}

答案 1 :(得分:3)

或者首先将其转换为字节数组,然后转换为bytearrayinputstream。

File f = new File(arg[0]);
InputStream in = new FileInputStream(f);
// convert the inpustream to a byte array
byte[] buf = null;
try {
    buf = new byte[in.available()];
    while (in.read(buf) != -1) {
    }
} catch (Exception e) {
    System.out.println("Got exception while is -> bytearr conversion: " + e);
}
// now convert it to a bytearrayinputstream
ByteArrayInputStream bin = new ByteArrayInputStream(buf);

答案 2 :(得分:2)

您可以使用org.apache.commons.io。 IOUtils#toByteArray (java.io.InputStream)

InputStream is = getMyInputStream();
ByteArrayInputStream bais = new ByteArrayInputStream(IOUtils.toByteArray(is));