java后台返回了一段hex数据,前端如何转化为图片?

发布网友发布时间：2022-05-12 21:30

共2个回答

热心网友时间：2023-10-23 18:42

两种思路，一种是你把图片下下来。告诉路径给前端。
另一种是你直接把图片转换成byte数组，返回给前端。前端是可以有办法的。（我用过这种用来爬虫爬验证码都是这么干的）

热心网友时间：2023-10-23 18:43

if (!window.atob) { var tableStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; var table = tableStr.split("");

window.atob = function (base64) { if (/(=[^=]+|={3,})$/.test(base64)) throw new Error("String contains an invalid character");
base64 = base64.replace(/=/g, ""); var n = base64.length & 3; if (n === 1) throw new Error("String contains an invalid character"); for (var i = 0, j = 0, len = base64.length / 4, bin = []; i < len; ++i) { var a = tableStr.indexOf(base64[j++] || "A"), b = tableStr.indexOf(base64[j++] || "A"); var c = tableStr.indexOf(base64[j++] || "A"), d = tableStr.indexOf(base64[j++] || "A"); if ((a | b | c | d) < 0) throw new Error("String contains an invalid character");
bin[bin.length] = ((a << 2) | (b >> 4)) & 255;
bin[bin.length] = ((b << 4) | (c >> 2)) & 255;
bin[bin.length] = ((c << 6) | d) & 255;
}; return String.fromCharCode.apply(null, bin).substr(0, bin.length + n - 4);
};

window.btoa = function (bin) { for (var i = 0, j = 0, len = bin.length / 3, base64 = []; i < len; ++i) { var a = bin.charCodeAt(j++), b = bin.charCodeAt(j++), c = bin.charCodeAt(j++); if ((a | b | c) > 255) throw new Error("String contains an invalid character");
base64[base64.length] = table[a >> 2] + table[((a << 4) & 63) | (b >> 4)] +
(isNaN(b) ? "=" : table[((b << 2) & 63) | (c >> 6)]) +
(isNaN(b + c) ? "=" : table[c & 63]);
} return base64.join("");
};

}

function hexToBase64(str) { return btoa(String.fromCharCode.apply(null,
str.replace(/\r|\n/g, "").replace(/([\da-fA-F]{2}) ?/g, "0x$1 ").replace(/ +$/, "").split(" "))
);
}

function base64ToHex(str) { for (var i = 0, bin = atob(str.replace(/[ \r\n]+$/, "")), hex = []; i < bin.length; ++i) { var tmp = bin.charCodeAt(i).toString(16); if (tmp.length === 1) tmp = "0" + tmp;
hex[hex.length] = tmp;
} return hex.join(" ");
}