文章目录
- 1. 问题描述
- 2. 原因
- 2.1 编码
- 2.2 解码
- 3. 解决方法
1. 问题描述
之前写了一个接口，用 Apifox 请求，参数传入一个 +86 的电话，结果到服务器 + 就变成空格了。
Java 接收请求的接口：
2. 原因
2.1 编码
进行 URL 请求的时候我们需要用 URLEncoder 对参数进行编码，下面是编码的规则。
/*** Utility class for HTML form encoding. This class contains static methods* for converting a String to the <CODE>application/x-www-form-urlencoded</CODE> MIME* format. For more information about HTML form encoding, consult the HTML* <A HREF="http://www.w3.org/TR/html4/">specification</A>.** <p>* When encoding a String, the following rules apply:** <ul>* <li>The alphanumeric characters "{@code a}" through* "{@code z}", "{@code A}" through* "{@code Z}" and "{@code 0}"* through "{@code 9}" remain the same.* <li>The special characters "{@code .}",* "{@code -}", "{@code *}", and* "{@code _}" remain the same.* <li>The space character " " is* converted into a plus sign "{@code +}".* <li>All other characters are unsafe and are first converted into* one or more bytes using some encoding scheme. Then each byte is* represented by the 3-character string* "<i>{@code %xy}</i>", where <i>xy</i> is the* two-digit hexadecimal representation of the byte.* The recommended encoding scheme to use is UTF-8. However,* for compatibility reasons, if an encoding is not specified,* then the default encoding of the platform is used.* </ul>** <p>* For example using UTF-8 as the encoding scheme the string "The* string ü@foo-bar" would get converted to* "The+string+%C3%BC%40foo-bar" because in UTF-8 the character* ü is encoded as two bytes C3 (hex) and BC (hex), and the* character @ is encoded as one byte 40 (hex).** @author Herb Jellinek* @since JDK1.0*/
public class URLEncoder {...
}
直接上 GPT，解释如下：
-
保留字符：
- 字母（a-z, A-Z）和数字（0-9）保持不变。
- 特殊字符 .（点）、-（减号）、*（星号）和 _（下划线）保持不变。
-
空格：
- 空格字符（ ）被转换为加号（+）。
-
其他字符：
- 所有其他字符被认为是“不安全的”，需要先使用某种编码方案（如UTF-8）转换为一个或多个字节，然后每个字节表示为%xy，其中xy是该字节的十六进制表示。
举个例子：假设使用UTF-8编码，字符串 “The string ü@foo-bar” 将被转换为 “The+string+%C3%BC%40foo-bar”，因为：
字符 ü 在UTF-8中编码为两个字节 C3 和 BC。
字符 @ 编码为一个字节 40。
2.2 解码
编码之后就能发送请求到服务器了，而我们直接在 Postman 上面请求的 URL 如下：
可以理解成编码之后的 URL，所以接收请求的时候同样会进行 URL 解码。那么 URL 是如何解码的呢？我们可以同样到 URLDecoder 里面去找答案：
/*** Utility class for HTML form decoding. This class contains static methods* for decoding a String from the <CODE>application/x-www-form-urlencoded</CODE>* MIME format.* <p>* The conversion process is the reverse of that used by the URLEncoder class. It is assumed* that all characters in the encoded string are one of the following:* "{@code a}" through "{@code z}",* "{@code A}" through "{@code Z}",* "{@code 0}" through "{@code 9}", and* "{@code -}", "{@code _}",* "{@code .}", and "{@code *}". The* character "{@code %}" is allowed but is interpreted* as the start of a special escaped sequence.* <p>* The following rules are applied in the conversion:** <ul>* <li>The alphanumeric characters "{@code a}" through* "{@code z}", "{@code A}" through* "{@code Z}" and "{@code 0}"* through "{@code 9}" remain the same.* <li>The special characters "{@code .}",* "{@code -}", "{@code *}", and* "{@code _}" remain the same.* <li>The plus sign "{@code +}" is converted into a* space character " " .* <li>A sequence of the form "<i>{@code %xy}</i>" will be* treated as representing a byte where <i>xy</i> is the two-digit* hexadecimal representation of the 8 bits. Then, all substrings* that contain one or more of these byte sequences consecutively* will be replaced by the character(s) whose encoding would result* in those consecutive bytes.* The encoding scheme used to decode these characters may be specified,* or if unspecified, the default encoding of the platform will be used.* </ul>* <p>* There are two possible ways in which this decoder could deal with* illegal strings. It could either leave illegal characters alone or* it could throw an {@link java.lang.IllegalArgumentException}.* Which approach the decoder takes is left to the* implementation.** @author Mark Chamness* @author Michael McCloskey* @since 1.2*/public class URLDecoder {...
}
还是一样，直接用 GPT 解释：
- **字母和数字：**字母a到z、A到Z和数字0到9保持不变。
- **特殊字符：**点号.、连字符-、星号*和下划线_保持不变。
- **加号：**加号+被转换为空格字符。
- **百分号编码：**形式为"%xy"的序列被视为表示一个字节，其中xy是该字节的两位十六进制表示。连续的这些字节序列将被替换为那些字节所表示的字符。字符的编码方案可以指定，如果没有指定，则使用平台的默认编码。
比如请求参数：http://localhost:8080/demo/getName?name=.-*_aA0+%2B
服务端这边的接收：.-*_aA0 +，可以看到 + 号解码成空格，同时 %2B 解码成 + 号了。因为 + 的 Ascii 十六进制就是 2B。
3. 解决方法
既然 + 号是被解码成空格了，那我们可以不把 + 号放在 URL 中，可以放在 Body 中，也就是使用 Post 请求，把参数放到请求体中传入就不会解码了。
@RequestMapping("/demo")
@RestController
public class DemoController {@GetMapping("getName")public void reqDemo(@RequestBody DataDemo dataDemo){System.out.println(dataDemo.getName());}
}@Getter
@Setter
public class DataDemo {private String name;
}
输出结果如下：
此外，还有一种方法，就是上面说的：传入 %2B 就行了。
如有错误，欢迎指出！！！
