java 中類似js encodeURIComponent 函數(shù)的實(shí)現(xiàn)案例

更新時(shí)間：2020年10月09日 11:00:00 作者：wangweiren_get

這篇文章主要介紹了java 中類似js encodeURIComponent 函數(shù)的實(shí)現(xiàn)案例，具有很好的參考價(jià)值，希望對(duì)大家有所幫助。一起跟隨小編過來看看吧

我就廢話不多說了，大家還是直接看代碼吧~

import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.net.URLEncoder;
 
/**
 * Utility class for JavaScript compatible UTF-8 encoding and decoding.
 * 
 * @see http://stackoverflow.com/questions/607176/java-equivalent-to-javascripts-encodeuricomponent-that-produces-identical-output
 * @author John Topley 
 */
public class EncodingUtil {
 /**
  * Decodes the passed UTF-8 String using an algorithm that's compatible with
  * JavaScript's <code>decodeURIComponent</code> function. Returns
  * <code>null</code> if the String is <code>null</code>.
  *
  * @param s The UTF-8 encoded String to be decoded
  * @return the decoded String
  */
 public static String decodeURIComponent(String s) {
  if (s == null) {
   return null;
  }
 
  String result = null;
 
  try {
   result = URLDecoder.decode(s, "UTF-8");
  }
 
  // This exception should never occur.
  catch (UnsupportedEncodingException e) {
   result = s; 
  }
 
  return result;
 }
 
 /**
  * Encodes the passed String as UTF-8 using an algorithm that's compatible
  * with JavaScript's <code>encodeURIComponent</code> function. Returns
  * <code>null</code> if the String is <code>null</code>.
  * 
  * @param s The String to be encoded
  * @return the encoded String
  */
 public static String encodeURIComponent(String s) {
  String result = null;
 
  try {
   result = URLEncoder.encode(s, "UTF-8")
             .replaceAll("\\+", "%20")
             .replaceAll("\\%21", "!")
             .replaceAll("\\%27", "'")
             .replaceAll("\\%28", "(")
             .replaceAll("\\%29", ")")
             .replaceAll("\\%7E", "~");
  }
 
  // This exception should never occur.
  catch (UnsupportedEncodingException e) {
   result = s;
  }
 
  return result;
 } 
 
 /**
  * Private constructor to prevent this class from being instantiated.
  */
 private EncodingUtil() {
  super();
 }
}

補(bǔ)充知識(shí)：java 代碼實(shí)現(xiàn)encodeURIComponent和decodeURIComponent，解決空格轉(zhuǎn)義為加號(hào)的問題

java自帶有一個(gè) java.net.URLDecoder和java.net.URLEncoder。

通過這兩個(gè)類，可以調(diào)用encode()或者decode()方法對(duì)字符串進(jìn)行URL編碼。

那既然有了，為什么還要自己實(shí)現(xiàn)一套呢？主要原因是Jdk中并沒有提供encodeURIComponent和decodeURIComponent的方法。

這兩個(gè)方法作用其實(shí)跟encode()和decode()基本相似。區(qū)別主要是，在java中，url編碼時(shí)，會(huì)把空格轉(zhuǎn)換成+號(hào)。而某些非java語言實(shí)現(xiàn)的客戶端一般空格轉(zhuǎn)義出來是 %20 ，這樣就容易發(fā)生decode不出這個(gè)空格的問題。比如IOS中，會(huì)把這個(gè)+直接顯示了，而不是轉(zhuǎn)義成空格。這就跟我們想要的結(jié)果違背了。比如js中就自帶有encodeURIComponent和decodeURIComponent的方法。

java我們就自己實(shí)現(xiàn)一下吧。直接看代碼，一看就明白。

/*
 * 文件名：URIEncode.java 描述： 修改人：gogym 修改時(shí)間：2018年11月16日 跟蹤單號(hào)： 修改單號(hào)： 修改內(nèi)容：
 */ 
 
import java.io.UnsupportedEncodingException; 
public class URIEncoder
{ 
  public static final String ALLOWED_CHARS = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-_.!~*'()";
 
  /**
   * Description:
   * 
   * @param str
   * @return
   * @throws UnsupportedEncodingException
   * @see
   */
  public static String encodeURI(String str)
    throws UnsupportedEncodingException
  {
    String isoStr = new String(str.getBytes("UTF8"), "ISO-8859-1");
    char[] chars = isoStr.toCharArray();
    StringBuffer sb = new StringBuffer();
    for (int i = 0; i < chars.length; i++ )
    {
      if ((chars[i] <= 'z' && chars[i] >= 'a') || (chars[i] <= 'Z' && chars[i] >= 'A')
        || chars[i] == '-' || chars[i] == '_' || chars[i] == '.' || chars[i] == '!'
        || chars[i] == '~' || chars[i] == '*' || chars[i] == '\'' || chars[i] == '('
        || chars[i] == ')' || chars[i] == ';' || chars[i] == '/' || chars[i] == '?'
        || chars[i] == ':' || chars[i] == '@' || chars[i] == '&' || chars[i] == '='
        || chars[i] == '+' || chars[i] == '$' || chars[i] == ',' || chars[i] == '#'
        || (chars[i] <= '9' && chars[i] >= '0'))
      {
        sb.append(chars[i]);
      }
      else
      {
        sb.append("%");
        sb.append(Integer.toHexString(chars[i]));
      }
    }
    return sb.toString();
  }
 
  /**
   * Description:
   * 
   * @param input
   * @return
   * @see
   */
  public static String encodeURIComponent(String input)
  {
    if (null == input || "".equals(input.trim()))
    {
      return input;
    }
 
    int l = input.length();
    StringBuilder o = new StringBuilder(l * 3);
    try
    {
      for (int i = 0; i < l; i++ )
      {
        String e = input.substring(i, i + 1);
        if (ALLOWED_CHARS.indexOf(e) == -1)
        {
          byte[] b = e.getBytes("utf-8");
          o.append(getHex(b));
          continue;
        }
        o.append(e);
      }
      return o.toString();
    }
    catch (UnsupportedEncodingException e)
    {
      e.printStackTrace();
    }
    return input;
  }
 
  private static String getHex(byte buf[])
  {
    StringBuilder o = new StringBuilder(buf.length * 3);
    for (int i = 0; i < buf.length; i++ )
    {
      int n = (int)buf[i] & 0xff;
      o.append("%");
      if (n < 0x10)
      {
        o.append("0");
      }
      o.append(Long.toString(n, 16).toUpperCase());
    }
    return o.toString();
  }
}

/*
 * 文件名：URIDecode.java 描述： 修改人：gogym 修改時(shí)間：2018年11月16日 跟蹤單號(hào)： 修改單號(hào)： 修改內(nèi)容：
 */
 
package com.poly.rbl.plugin.uri; 
public class URIDecoder
{ 
  /**
   * 
   * Description: 
   * 
   * @param encodedURI
   * @return 
   * @see
   */
  public static String decodeURIComponent(String encodedURI)
  {
    char actualChar;
 
    StringBuffer buffer = new StringBuffer();
 
    int bytePattern, sumb = 0;
 
    for (int i = 0, more = -1; i < encodedURI.length(); i++ )
    {
      actualChar = encodedURI.charAt(i);
 
      switch (actualChar)
      {
        case '%':
        {
          actualChar = encodedURI.charAt(++i);
          int hb = (Character.isDigit(actualChar) ? actualChar - '0' : 10 + Character.toLowerCase(actualChar) - 'a') & 0xF;
          actualChar = encodedURI.charAt(++i);
          int lb = (Character.isDigit(actualChar) ? actualChar - '0' : 10 + Character.toLowerCase(actualChar) - 'a') & 0xF;
          bytePattern = (hb << 4) | lb;
          break;
        }
        case '+':
        {
          bytePattern = ' ';
          break;
        }
        default:
        {
          bytePattern = actualChar;
        }
      }
 
      if ((bytePattern & 0xc0) == 0x80)
      { // 10xxxxxx
        sumb = (sumb << 6) | (bytePattern & 0x3f);
        if (--more == 0) buffer.append((char)sumb);
      }
      else if ((bytePattern & 0x80) == 0x00)
      { // 0xxxxxxx
        buffer.append((char)bytePattern);
      }
      else if ((bytePattern & 0xe0) == 0xc0)
      { // 110xxxxx
        sumb = bytePattern & 0x1f;
        more = 1;
      }
      else if ((bytePattern & 0xf0) == 0xe0)
      { // 1110xxxx
        sumb = bytePattern & 0x0f;
        more = 2;
      }
      else if ((bytePattern & 0xf8) == 0xf0)
      { // 11110xxx
        sumb = bytePattern & 0x07;
        more = 3;
      }
      else if ((bytePattern & 0xfc) == 0xf8)
      { // 111110xx
        sumb = bytePattern & 0x03;
        more = 4;
      }
      else
      { // 1111110x
        sumb = bytePattern & 0x01;
        more = 5;
      }
    }
    return buffer.toString();
  }
}

以上這篇java 中類似js encodeURIComponent 函數(shù)的實(shí)現(xiàn)案例就是小編分享給大家的全部?jī)?nèi)容了，希望能給大家一個(gè)參考，也希望大家多多支持腳本之家。

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