问题描述
是否可以将byte[]
(字节数组)放入JSON
?
Is it possible to put a byte[]
(byte array) to JSON
?
如果是这样,我怎么能在java中做到这一点?然后读取该 JSON 并将该字段再次转换为 byte[]
?
if so, how can I do that in java? then read that JSON and convert that field again to byte[]
?
推荐答案
这是 base64 编码字节数组的一个很好的例子.当您将 unicode 字符混入以发送 PDF 文档之类的内容时,情况会变得更加复杂.对字节数组进行编码后,编码后的字符串可以用作 JSON 属性值.
Here is a good example of base64 encoding byte arrays. It gets more complicated when you throw unicode characters in the mix to send things like PDF documents. After encoding a byte array the encoded string can be used as a JSON property value.
Apache commons 提供了很好的实用程序:
Apache commons offers good utilities:
byte[] bytes = getByteArr();
String base64String = Base64.encodeBase64String(bytes);
byte[] backToBytes = Base64.decodeBase64(base64String);
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Base64_encoding_and_decoding
Java 服务器端示例:
Java server side example:
public String getUnsecureContentBase64(String url)
throws ClientProtocolException, IOException {
//getUnsecureContent will generate some byte[]
byte[] result = getUnsecureContent(url);
// use apache org.apache.commons.codec.binary.Base64
// if you're sending back as a http request result you may have to
// org.apache.commons.httpclient.util.URIUtil.encodeQuery
return Base64.encodeBase64String(result);
}
JavaScript 解码:
JavaScript decode:
//decode URL encoding if encoded before returning result
var uriEncodedString = decodeURIComponent(response);
var byteArr = base64DecToArr(uriEncodedString);
//from mozilla
function b64ToUint6 (nChr) {
return nChr > 64 && nChr < 91 ?
nChr - 65
: nChr > 96 && nChr < 123 ?
nChr - 71
: nChr > 47 && nChr < 58 ?
nChr + 4
: nChr === 43 ?
62
: nChr === 47 ?
63
:
0;
}
function base64DecToArr (sBase64, nBlocksSize) {
var
sB64Enc = sBase64.replace(/[^A-Za-z0-9\+\/]/g, ""), nInLen = sB64Enc.length,
nOutLen = nBlocksSize ? Math.ceil((nInLen * 3 + 1 >> 2) / nBlocksSize) * nBlocksSize : nInLen * 3 + 1 >> 2, taBytes = new Uint8Array(nOutLen);
for (var nMod3, nMod4, nUint24 = 0, nOutIdx = 0, nInIdx = 0; nInIdx < nInLen; nInIdx++) {
nMod4 = nInIdx & 3;
nUint24 |= b64ToUint6(sB64Enc.charCodeAt(nInIdx)) << 18 - 6 * nMod4;
if (nMod4 === 3 || nInLen - nInIdx === 1) {
for (nMod3 = 0; nMod3 < 3 && nOutIdx < nOutLen; nMod3++, nOutIdx++) {
taBytes[nOutIdx] = nUint24 >>> (16 >>> nMod3 & 24) & 255;
}
nUint24 = 0;
}
}
return taBytes;
}
这篇关于将字节数组放入 JSON,反之亦然的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!