Java学习笔记——IO操作之以图片地址下载图片

以图片地址下载图片
读取给定图片文件的内容，用FileInputStream

[java]
public static byte[] mReaderPicture(String filePath) {
    byte[] arr = null;
    try {
        File file = new File(filePath);
        FileInputStream fReader = new FileInputStream(file);
        arr = new byte[1024*100];
        fReader.read(arr);
    } catch (Exception e) {
        // TODO: handle exception
        e.printStackTrace();
    }
    return arr;
}

public static byte[] mReaderPicture(String filePath) {
  byte[] arr = null;
  try {
   File file = new File(filePath);
   FileInputStream fReader = new FileInputStream(file);
   arr = new byte[1024*100];
   fReader.read(arr);
  } catch (Exception e) {
   // TODO: handle exception
   e.printStackTrace();
  }
  return arr;
}

根据byte数组，创建一张新图。
[java]
public static void mWriterPicture(String newFileName,byte[] b){
    try {
        File file = new File(newFileName);
        FileOutputStream fStream = new FileOutputStream(file);
        fStream.write(b);
        fStream.close();
        System.out.println("图片创建成功    "+b.length);
    } catch (Exception e) {
        // TODO: handle exception
    }
}

public static void mWriterPicture(String newFileName,byte[] b){
  try {
   File file = new File(newFileName);
   FileOutputStream fStream = new FileOutputStream(file);
   fStream.write(b);
   fStream.close();
   System.out.println("图片创建成功    "+b.length);
  } catch (Exception e) {
   // TODO: handle exception
  }
}

获取指定网址的图片，返回其byte[]
[java]
public static byte[] mReaderPictureToInternet(String strUr1){
    byte[] imgData = null;
    URL url;
    try {
        url = new URL(strUr1);
        URLConnection connection = url.openConnection();
        int length = (int)connection.getContentLength();
        InputStream is = connection.getInputStream();
        if (length!=-1) {
            imgData = new byte[length];
            byte[] temp = new byte[500*1024];
            int readLen = 0;
            int destPos = 0;
            while ((readLen = is.read(temp))>0) {
                System.arraycopy(temp, 0, imgData, destPos, readLen);
                //arraycopy(Object src, int srcPos, Object dest, int destPos, int length)
                //从指定源数组中复制一个数组，复制从指定的位置开始，到目标数组的指定位置结束
                destPos+=readLen;
            }
        }
        return imgData;
    } catch (Exception e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    return imgData;
}

public static byte[] mReaderPictureToInternet(String strUr1){
  byte[] imgData = null;
  URL url;
  try {
   url = new URL(strUr1);
   URLConnection connection = url.openConnection();
   int length = (int)connection.getContentLength();
   InputStream is = connection.getInputStream();
   if (length!=-1) {
    imgData = new byte[length];
    byte[] temp = new byte[500*1024];
    int readLen = 0;
    int destPos = 0;
    while ((readLen = is.read(temp))>0) {
     System.arraycopy(temp, 0, imgData, destPos, readLen);
     //arraycopy(Object src, int srcPos, Object dest, int destPos, int length)
     //从指定源数组中复制一个数组，复制从指定的位置开始，到目标数组的指定位置结束
     destPos+=readLen;
    }
   }
   return imgData;
  } catch (Exception e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }
  return imgData;
}

直接获取指定网址的图片
[java]
public static void DownPictureToInternet(String filePath,String strUr1){
    try {
        URL url = new URL(strUr1);
        InputStream fStream = url.openConnection().getInputStream();
        int b = 0;
        FileOutputStream fos = new FileOutputStream(new File(filePath));
        while ((b=fStream.read())!=-1) {
            fos.write(b);
        }
        fStream.close();
        fos.close();
    } catch (Exception e) {
        e.printStackTrace();
    }
}

public static void DownPictureToInternet(String filePath,String strUr1){
  try {
   URL url = new URL(strUr1);
   I

补充：软件开发 , Java ,