项目在登录、注册等场景实现时，经常会用到用户信息前端加密，然后项目后端二次解密，避免信息直接在浏览器上以明文显示。

本文主要介绍了base64加密的方式处理代码，不支持中文

源码如下：

base64.js

// base64加密开始  
    var keyStr = "ABCDEFGHIJKLMNOP" + "QRSTUVWXYZabcdef" + "ghijklmnopqrstuv"  
            + "wxyz0123456789+/" + "=";  
      
    function encode64(input) {  
 
        var output = "";  
        var chr1, chr2, chr3 = "";  
        var enc1, enc2, enc3, enc4 = "";  
        var i = 0;  
        do {  
            chr1 = input.charCodeAt(i++);  
            chr2 = input.charCodeAt(i++);  
            chr3 = input.charCodeAt(i++);  
            enc1 = chr1 >> 2;  
            enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);  
            enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);  
            enc4 = chr3 & 63;  
            if (isNaN(chr2)) {  
                enc3 = enc4 = 64;  
            } else if (isNaN(chr3)) {  
                enc4 = 64;  
            }  
            output = output + keyStr.charAt(enc1) + keyStr.charAt(enc2)  
                    + keyStr.charAt(enc3) + keyStr.charAt(enc4);  
            chr1 = chr2 = chr3 = "";  
            enc1 = enc2 = enc3 = enc4 = "";  
        } while (i < input.length);  
 
        return output;  
    }  
    // base64加密结束

JAVA代码如下：

public class Test{

public static void main(String[] args) throws IOException {
    String source = "asdklsakjfdlsadjfl12ACB";
    BASE64Encoder base64 = new BASE64Encoder();
    String result = base64.encode((source).getBytes());

    System.out.printf("encode source is %s,result is %s",source,result);
    System.out.println("------------------");
    BASE64Decoder base64dec = new BASE64Decoder();
    System.out.printf("decodeBuffer source is %s,result is %s",result,new String(base64dec.decodeBuffer(result)));

}

}

运行结果如下：

encode source is asdklsakjfdlsadjfl12ACB,result is YXNka2xzYWtqZmRsc2FkamZsMTJBQ0I=------------------
decodeBuffer source is YXNka2xzYWtqZmRsc2FkamZsMTJBQ0I=,result is asdklsakjfdlsadjfl12ACB

Process finished with exit code 0