对 url 中含有的中文进行转码操作
一般情况下，将带有中文的 url 拷贝到开发工具，开发工具都会有相应的转码（自动转码），
现在大部分的浏览器也可以对含有中文的 url 进行转码（自动转码）
情景说明
android
安卓系统，能够识别中文路径：
https://spdbimg.idoupiao.com/film/my/美国队长3
IOS
苹果系统，不能够识别中文路径：
https://spdbimg.idoupiao.com/film/my/美国队长3
必须将以上路径进行转码为下来形式才可以访问：
https://spdbimg.idoupiao.com/film/my/%E7%BE%8E%E5%9B%BD%E9%98%9F%E9%95%BF3
这和他们各自的战略定位有关系。。。
编码实现
1、先寻找有没有已经实现类似功能的成熟工具。
2、找到 JDK 提供的 URLEncoder 类的 encode 方法基本满足需求。
3、测试是否满足当下需求。
经过测试发现，JDK 提供的 URLEncoder 类的 encode 方法会将 ':' 和 '/' 等字符也进行编码。
4、查找 JDK 提供的 URLEncoder 类的 encode 方法 相关源码。
5、发现可以进行部分改造满足当前需求，重写 URLEncoder 类，并将其设置为私有静态类，多人合作时，防止他人误用。
6、改造完成进行验证型测试。
添加以下两条语句：
// 排除这两个特殊字符的编码
dontNeedEncoding.set(':');
dontNeedEncoding.set('/');
重写后的 URLEncoder 类：
/**
* 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
*/
private static class URLEncoder {
static BitSet dontNeedEncoding;
static final int caseDiff = ('a' - 'A');
static String dfltEncName = null;
static {
/* The list of characters that are not encoded has been
* determined as follows:
*
* RFC 2396 states:
* -----
* Data characters that are allowed in a URI but do not have a
* reserved purpose are called unreserved. These include upper
* and lower case letters, decimal digits, and a limited set of
* punctuation marks and symbols.
*
* unreserved = alphanum | mark
*
* mark = "-" | "_" | "." | "!" | "~" | "*" | "'" | "(" | ")"
*
* Unreserved characters can be escaped without changing the
* semantics of the URI, but this should not be done unless the
* URI is being used in a context that does not allow the
* unescaped character to appear.
* -----
*
* It appears that both Netscape and Internet Explorer escape
* all special characters from this list with the exception
* of "-", "_", ".", "*". While it is not clear why they are
* escaping the other characters, perhaps it is safest to
* assume that there might be contexts in which the others
* are unsafe if not escaped. Therefore, we will use the same
* list. It is also noteworthy that this is consistent with
* O'Reilly's "HTML: The Definitive Guide" (page 164).
*
* As a last note, Intenet Explorer does not encode the "@"
* character which is clearly not unreserved according to the
* RFC. We are being consistent with the RFC in this matter,
* as is Netscape.
*
*/
dontNeedEncoding = new BitSet(256);
int i;
for (i = 'a'; i <= 'z'; i++) {
dontNeedEncoding.set(i);
}
for (i = 'A'; i <= 'Z'; i++) {
dontNeedEncoding.set(i);
}
for (i = '0'; i <= '9'; i++) {
dontNeedEncoding.set(i);
}
dontNeedEncoding.set(' '); /* encoding a space to a + is done
* in the encode() method */
dontNeedEncoding.set('-');
dontNeedEncoding.set('_');
dontNeedEncoding.set('.');
dontNeedEncoding.set('*');
// 排除这两个特殊字符的编码
dontNeedEncoding.set(':');
dontNeedEncoding.set('/');
dfltEncName = AccessController.doPrivileged(
new GetPropertyAction("file.encoding")
);
}
/**
* You can't call the constructor.
*/
private URLEncoder() { }
/**
* Translates a string into {@code x-www-form-urlencoded}
* format. This method uses the platform's default encoding
* as the encoding scheme to obtain the bytes for unsafe characters.
*
* @param s {@code String} to be translated.
* @deprecated The resulting string may vary depending on the platform's
* default encoding. Instead, use the encode(String,String)
* method to specify the encoding.
* @return the translated {@code String}.
*/
@Deprecated
public static String encode(String s) {
String str = null;
try {
str = encode(s, dfltEncName);
} catch (UnsupportedEncodingException e) {
// The system should always have the platform default
}
return str;
}
/**
* Translates a string into {@code application/x-www-form-urlencoded}
* format using a specific encoding scheme. This method uses the
* supplied encoding scheme to obtain the bytes for unsafe
* characters.
* <p>
* <em><strong>Note:</strong> The <a href=
* "http://www.w3.org/TR/html40/appendix/notes.html#non-ascii-chars">
* World Wide Web Consortium Recommendation</a> states that
* UTF-8 should be used. Not doing so may introduce
* incompatibilities.</em>
*
* @param s {@code String} to be translated.
* @param enc The name of a supported
* <a href="../lang/package-summary.html#charenc">character
* encoding</a>.
* @return the translated {@code String}.
* @exception UnsupportedEncodingException
* If the named encoding is not supported
* @see URLDecoder#decode(java.lang.String, java.lang.String)
* @since 1.4
*/
public static String encode(String s, String enc)
throws UnsupportedEncodingException {
boolean needToChange = false;
StringBuffer out = new StringBuffer(s.length());
Charset charset;
CharArrayWriter charArrayWriter = new CharArrayWriter();
if (enc == null)
throw new NullPointerException("charsetName");
try {
charset = Charset.forName(enc);
} catch (IllegalCharsetNameException e) {
throw new UnsupportedEncodingException(enc);
} catch (UnsupportedCharsetException e) {
throw new UnsupportedEncodingException(enc);
}
for (int i = 0; i < s.length();) {
int c = (int) s.charAt(i);
//System.out.println("Examining character: " + c);
if (dontNeedEncoding.get(c)) {
if (c == ' ') {
c = '+';
needToChange = true;
}
//System.out.println("Storing: " + c);
out.append((char)c);
i++;
} else {
// convert to external encoding before hex conversion
do {
charArrayWriter.write(c);
/*
* If this character represents the start of a Unicode
* surrogate pair, then pass in two characters. It's not
* clear what should be done if a bytes reserved in the
* surrogate pairs range occurs outside of a legal
* surrogate pair. For now, just treat it as if it were
* any other character.
*/
if (c >= 0xD800 && c <= 0xDBFF) {
/*
System.out.println(Integer.toHexString(c)
+ " is high surrogate");
*/
if ( (i+1) < s.length()) {
int d = (int) s.charAt(i+1);
/*
System.out.println(" Examining "
+ Integer.toHexString(d));
*/
if (d >= 0xDC00 && d <= 0xDFFF) {
/*
System.out.println(" "
+ Integer.toHexString(d)
+ " is low surrogate");
*/
charArrayWriter.write(d);
i++;
}
}
}
i++;
} while (i < s.length() && !dontNeedEncoding.get((c = (int) s.charAt(i))));
charArrayWriter.flush();
String str = new String(charArrayWriter.toCharArray());
byte[] ba = str.getBytes(charset);
for (int j = 0; j < ba.length; j++) {
out.append('%');
char ch = Character.forDigit((ba[j] >> 4) & 0xF, 16);
// converting to use uppercase letter as part of
// the hex value if ch is a letter.
if (Character.isLetter(ch)) {
ch -= caseDiff;
}
out.append(ch);
ch = Character.forDigit(ba[j] & 0xF, 16);
if (Character.isLetter(ch)) {
ch -= caseDiff;
}
out.append(ch);
}
charArrayWriter.reset();
needToChange = true;
}
}
return (needToChange? out.toString() : s);
}
}
测试代码：
@Test
public void testReplace() throws UnsupportedEncodingException {
// https://ojjqzz83h.qnssl.com/film/my/美国队长3?imageView2/1/w/140/h/90/interlace/0/q/100
// https://spdbimg.idoupiao.com/film/my/%E7%BE%8E%E5%9B%BD%E9%98%9F%E9%95%BF3
String oldImgUrl = "https://spdbimg.idoupiao.com/film/my/美国队长3";
oldImgUrl = URLEncoder.encode(oldImgUrl, "UTF-8");
// oldImgUrl = new String(Base64.getEncoder().encode(oldImgUrl.getBytes()));
String oldDomain = "spdbimg.idoupiao.com";
String newDomain = "ojjqzz83h.qnssl.com";
String suffix = "?imageView2/1/w/140/h/90/interlace/0/q/100";
String newImgUrl = StringUtils.replace(oldImgUrl, oldDomain, newDomain).concat(suffix);
System.out.println("newImgUrl === " + newImgUrl);
}
完整代码如下：
package com.github.ljmatlight.util;
import org.junit.Test;
import sun.security.action.GetPropertyAction;
import java.io.CharArrayWriter;
import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.nio.charset.Charset;
import java.nio.charset.IllegalCharsetNameException;
import java.nio.charset.UnsupportedCharsetException;
import java.security.AccessController;
import java.util.BitSet;
/**
* Description：对 url 中含有的中文进行转码操作
* <br /> Author：ljmatlight
*/
public class StringTest {
@Test
public void testReplace() throws UnsupportedEncodingException {
// https://ojjqzz83h.qnssl.com/film/my/美国队长3?imageView2/1/w/140/h/90/interlace/0/q/100
// https://spdbimg.idoupiao.com/film/my/%E7%BE%8E%E5%9B%BD%E9%98%9F%E9%95%BF3
String oldImgUrl = "https://spdbimg.idoupiao.com/film/my/美国队长3";
oldImgUrl = URLEncoder.encode(oldImgUrl, "UTF-8");
// oldImgUrl = new String(Base64.getEncoder().encode(oldImgUrl.getBytes()));
String oldDomain = "spdbimg.idoupiao.com";
String newDomain = "ojjqzz83h.qnssl.com";
String suffix = "?imageView2/1/w/140/h/90/interlace/0/q/100";
String newImgUrl = StringUtils.replace(oldImgUrl, oldDomain, newDomain).concat(suffix);
System.out.println("newImgUrl === " + newImgUrl);
}
/**
* 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
*/
private static class URLEncoder {
static BitSet dontNeedEncoding;
static final int caseDiff = ('a' - 'A');
static String dfltEncName = null;
static {
/* The list of characters that are not encoded has been
* determined as follows:
*
* RFC 2396 states:
* -----
* Data characters that are allowed in a URI but do not have a
* reserved purpose are called unreserved. These include upper
* and lower case letters, decimal digits, and a limited set of
* punctuation marks and symbols.
*
* unreserved = alphanum | mark
*
* mark = "-" | "_" | "." | "!" | "~" | "*" | "'" | "(" | ")"
*
* Unreserved characters can be escaped without changing the
* semantics of the URI, but this should not be done unless the
* URI is being used in a context that does not allow the
* unescaped character to appear.
* -----
*
* It appears that both Netscape and Internet Explorer escape
* all special characters from this list with the exception
* of "-", "_", ".", "*". While it is not clear why they are
* escaping the other characters, perhaps it is safest to
* assume that there might be contexts in which the others
* are unsafe if not escaped. Therefore, we will use the same
* list. It is also noteworthy that this is consistent with
* O'Reilly's "HTML: The Definitive Guide" (page 164).
*
* As a last note, Intenet Explorer does not encode the "@"
* character which is clearly not unreserved according to the
* RFC. We are being consistent with the RFC in this matter,
* as is Netscape.
*
*/
dontNeedEncoding = new BitSet(256);
int i;
for (i = 'a'; i <= 'z'; i++) {
dontNeedEncoding.set(i);
}
for (i = 'A'; i <= 'Z'; i++) {
dontNeedEncoding.set(i);
}
for (i = '0'; i <= '9'; i++) {
dontNeedEncoding.set(i);
}
dontNeedEncoding.set(' '); /* encoding a space to a + is done
* in the encode() method */
dontNeedEncoding.set('-');
dontNeedEncoding.set('_');
dontNeedEncoding.set('.');
dontNeedEncoding.set('*');
// 排除这两个特殊字符的编码
dontNeedEncoding.set(':');
dontNeedEncoding.set('/');
dfltEncName = AccessController.doPrivileged(
new GetPropertyAction("file.encoding")
);
}
/**
* You can't call the constructor.
*/
private URLEncoder() { }
/**
* Translates a string into {@code x-www-form-urlencoded}
* format. This method uses the platform's default encoding
* as the encoding scheme to obtain the bytes for unsafe characters.
*
* @param s {@code String} to be translated.
* @deprecated The resulting string may vary depending on the platform's
* default encoding. Instead, use the encode(String,String)
* method to specify the encoding.
* @return the translated {@code String}.
*/
@Deprecated
public static String encode(String s) {
String str = null;
try {
str = encode(s, dfltEncName);
} catch (UnsupportedEncodingException e) {
// The system should always have the platform default
}
return str;
}
/**
* Translates a string into {@code application/x-www-form-urlencoded}
* format using a specific encoding scheme. This method uses the
* supplied encoding scheme to obtain the bytes for unsafe
* characters.
* <p>
* <em><strong>Note:</strong> The <a href=
* "http://www.w3.org/TR/html40/appendix/notes.html#non-ascii-chars">
* World Wide Web Consortium Recommendation</a> states that
* UTF-8 should be used. Not doing so may introduce
* incompatibilities.</em>
*
* @param s {@code String} to be translated.
* @param enc The name of a supported
* <a href="../lang/package-summary.html#charenc">character
* encoding</a>.
* @return the translated {@code String}.
* @exception UnsupportedEncodingException
* If the named encoding is not supported
* @see URLDecoder#decode(java.lang.String, java.lang.String)
* @since 1.4
*/
public static String encode(String s, String enc)
throws UnsupportedEncodingException {
boolean needToChange = false;
StringBuffer out = new StringBuffer(s.length());
Charset charset;
CharArrayWriter charArrayWriter = new CharArrayWriter();
if (enc == null)
throw new NullPointerException("charsetName");
try {
charset = Charset.forName(enc);
} catch (IllegalCharsetNameException e) {
throw new UnsupportedEncodingException(enc);
} catch (UnsupportedCharsetException e) {
throw new UnsupportedEncodingException(enc);
}
for (int i = 0; i < s.length();) {
int c = (int) s.charAt(i);
//System.out.println("Examining character: " + c);
if (dontNeedEncoding.get(c)) {
if (c == ' ') {
c = '+';
needToChange = true;
}
//System.out.println("Storing: " + c);
out.append((char)c);
i++;
} else {
// convert to external encoding before hex conversion
do {
charArrayWriter.write(c);
/*
* If this character represents the start of a Unicode
* surrogate pair, then pass in two characters. It's not
* clear what should be done if a bytes reserved in the
* surrogate pairs range occurs outside of a legal
* surrogate pair. For now, just treat it as if it were
* any other character.
*/
if (c >= 0xD800 && c <= 0xDBFF) {
/*
System.out.println(Integer.toHexString(c)
+ " is high surrogate");
*/
if ( (i+1) < s.length()) {
int d = (int) s.charAt(i+1);
/*
System.out.println(" Examining "
+ Integer.toHexString(d));
*/
if (d >= 0xDC00 && d <= 0xDFFF) {
/*
System.out.println(" "
+ Integer.toHexString(d)
+ " is low surrogate");
*/
charArrayWriter.write(d);
i++;
}
}
}
i++;
} while (i < s.length() && !dontNeedEncoding.get((c = (int) s.charAt(i))));
charArrayWriter.flush();
String str = new String(charArrayWriter.toCharArray());
byte[] ba = str.getBytes(charset);
for (int j = 0; j < ba.length; j++) {
out.append('%');
char ch = Character.forDigit((ba[j] >> 4) & 0xF, 16);
// converting to use uppercase letter as part of
// the hex value if ch is a letter.
if (Character.isLetter(ch)) {
ch -= caseDiff;
}
out.append(ch);
ch = Character.forDigit(ba[j] & 0xF, 16);
if (Character.isLetter(ch)) {
ch -= caseDiff;
}
out.append(ch);
}
charArrayWriter.reset();
needToChange = true;
}
}
return (needToChange? out.toString() : s);
}
}
}
作者：随风浮云
出处：http://www.cnblogs.com/ljmatlight
本文版权归作者所有，欢迎转载，但未经作者同意必须保留此段声明。
文中有不妥或者错误的地方，欢迎勘误，如果你有更好的建议，可以给我留言讨论，共同进步。
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