这段 js 代码 Java 应该怎么写 有大佬解读下吗

function sign(t, n) {
var o = [];
for (var r in t) o.push("".concat(r, "=").concat(t[r]));
var a = "".concat(o.join("&")).concat("xxxxxxx");
return n && (a = "".concat(a).concat(JSON.stringify(n))),
a = a.replace(//gm, "c")
.replace(/e/gm, "g")
.replace(new RegExp(" ", "gm"), ""),
(0, _default)(a);
}

function __default(n1, r1, t1) {
if (!r1) return t1 ? l(n1) : a(l(n1));
if (!t1) return a(g(r1, n1));
return g(r1, n1);

function n(n, r) {
var t = (65535 & n) + (65535 & r);
return (n >> 16) + (r >> 16) + (t >> 16) << 16 | 65535 & t;
}

function r(r, t, e, u, o, c) {
return n((f = n(n(t, r), n(u, c))) << (i = o) | f >>> 32 - i, e);
var f, i;
}

function t(n, t, e, u, o, c, f) {
return r(t & e | ~t & u, n, t, o, c, f);
}

function e(n, t, e, u, o, c, f) {
return r(t & u | e & ~u, n, t, o, c, f);
}

function u(n, t, e, u, o, c, f) {
return r(t ^ e ^ u, n, t, o, c, f);
}

function o(n, t, e, u, o, c, f) {
return r(e ^ (t | ~u), n, t, o, c, f);
}

function c(r, c) {
r[c >> 5] |= 128 << c % 32, r[14 + (c + 64 >>> 9 << 4)] = c;
var f, i, a, h, l, g = 1732584193, v = -271733879, d = -1732584194, C = 271733878;
for (f = 0; f < r.length; f += 16) i = g, a = v, h = d, l = C, g = t(g, v, d, C, r[f], 7, -680876936),
C = t(C, g, v, d, r[f + 1], 12, -389564586), d = t(d, C, g, v, r[f + 2], 17, 606105819),
v = t(v, d, C, g, r[f + 3], 22, -1044525330), g = t(g, v, d, C, r[f + 4], 7, -176418897),
C = t(C, g, v, d, r[f + 5], 12, 1200080426), d = t(d, C, g, v, r[f + 6], 17, -1473231341),
v = t(v, d, C, g, r[f + 7], 22, -45705983), g = t(g, v, d, C, r[f + 8], 7, 1770035416),
C = t(C, g, v, d, r[f + 9], 12, -1958414417), d = t(d, C, g, v, r[f + 10], 17, -42063),
v = t(v, d, C, g, r[f + 11], 22, -1990404162), g = t(g, v, d, C, r[f + 12], 7, 1804603682),
C = t(C, g, v, d, r[f + 13], 12, -40341101), d = t(d, C, g, v, r[f + 14], 17, -1502002290),
g = e(g, v = t(v, d, C, g, r[f + 15], 22, 1236535329), d, C, r[f + 1], 5, -165796510),
C = e(C, g, v, d, r[f + 6], 9, -1069501632), d = e(d, C, g, v, r[f + 11], 14, 643717713),
v = e(v, d, C, g, r[f], 20, -373897302), g = e(g, v, d, C, r[f + 5], 5, -701558691),
C = e(C, g, v, d, r[f + 10], 9, 38016083), d = e(d, C, g, v, r[f + 15], 14, -660478335),
v = e(v, d, C, g, r[f + 4], 20, -405537848), g = e(g, v, d, C, r[f + 9], 5, 568446438),
C = e(C, g, v, d, r[f + 14], 9, -1019803690), d = e(d, C, g, v, r[f + 3], 14, -187363961),
v = e(v, d, C, g, r[f + 8], 20, 1163531501), g = e(g, v, d, C, r[f + 13], 5, -1444681467),
C = e(C, g, v, d, r[f + 2], 9, -51403784), d = e(d, C, g, v, r[f + 7], 14, 1735328473),
g = u(g, v = e(v, d, C, g, r[f + 12], 20, -1926607734), d, C, r[f + 5], 4, -378558),
C = u(C, g, v, d, r[f + 8], 11, -2022574463), d = u(d, C, g, v, r[f + 11], 16, 1839030562),
v = u(v, d, C, g, r[f + 14], 23, -35309556), g = u(g, v, d, C, r[f + 1], 4, -1530992060),
C = u(C, g, v, d, r[f + 4], 11, 1272893353), d = u(d, C, g, v, r[f + 7], 16, -155497632),
v = u(v, d, C, g, r[f + 10], 23, -1094730640), g = u(g, v, d, C, r[f + 13], 4, 681279174),
C = u(C, g, v, d, r[f], 11, -358537222), d = u(d, C, g, v, r[f + 3], 16, -722521979),
v = u(v, d, C, g, r[f + 6], 23, 76029189), g = u(g, v, d, C, r[f + 9], 4, -640364487),
C = u(C, g, v, d, r[f + 12], 11, -421815835), d = u(d, C, g, v, r[f + 15], 16, 530742520),
g = o(g, v = u(v, d, C, g, r[f + 2], 23, -995338651), d, C, r[f], 6, -198630844),
C = o(C, g, v, d, r[f + 7], 10, 1126891415), d = o(d, C, g, v, r[f + 14], 15, -1416354905),
v = o(v, d, C, g, r[f + 5], 21, -57434055), g = o(g, v, d, C, r[f + 12], 6, 1700485571),
C = o(C, g, v, d, r[f + 3], 10, -1894986606), d = o(d, C, g, v, r[f + 10], 15, -1051523),
v = o(v, d, C, g, r[f + 1], 21, -2054922799), g = o(g, v, d, C, r[f + 8], 6, 1873313359),
C = o(C, g, v, d, r[f + 15], 10, -30611744), d = o(d, C, g, v, r[f + 6], 15, -1560198380),
v = o(v, d, C, g, r[f + 13], 21, 1309151649), g = o(g, v, d, C, r[f + 4], 6, -145523070),
C = o(C, g, v, d, r[f + 11], 10, -1120210379), d = o(d, C, g, v, r[f + 2], 15, 718787259),
v = o(v, d, C, g, r[f + 9], 21, -343485551), g = n(g, i), v = n(v, a), d = n(d, h),
C = n(C, l);
return [ g, v, d, C ];
}

function f(n) {
var r, t = "";
for (r = 0; r < 32 * n.length; r += 8) t += String.fromCharCode(n[r >> 5] >>> r % 32 & 255);
return t;
}

function i(n) {
var r, t = [];
for (t[(n.length >> 2) - 1] = void 0, r = 0; r < t.length; r += 1) t[r] = 0;
for (r = 0; r < 8 * n.length; r += 8) t[r >> 5] |= (255 & n.charCodeAt(r / 8)) << r % 32;
return t;
}

function a(n) {
var r, t, e = "";
for (t = 0; t < n.length; t += 1) r = n.charCodeAt(t), e += "0123456789ABCDEF".charAt(r >>> 4 & 15) + "0123456789ABCDEF".charAt(15 & r);
return e;
}

function h(n) {
return unescape(encodeURIComponent(n));
}

function l(n) {
return function(n) {
return f(c(i(n), 8 * n.length));
}(h(n));
}

function g(n, r) {
return function(n, r) {
var t, e, u = i(n), o = [], a = [];
for (o[15] = a[15] = void 0, u.length > 16 && (u = c(u, 8 * n.length)), t = 0; t < 16; t += 1) o[t] = 909522486 ^ u[t],
a[t] = 1549556828 ^ u[t];
return e = c(o.concat(i(r)), 512 + 8 * r.length), f(c(a.concat(e), 640));
}(h(n), h(r));
}

}