Java同樣的漢字在伺服器和本地的電腦上URLencode 出來的結果不一致
阿新 • • 發佈：2018-12-09
同樣的漢字在伺服器和本地的電腦上URLencode 出來的結果不一致
在CSDN問答中看到這個問題，通常這類問題都是由於字串的編碼導致的。
程式碼如下：
String oldStr = new String("中文字元"); //我的環境預設UTF-8 System.out.println(URLEncoder.encode(oldStr)); try { String newStr = new String(oldStr.getBytes(), "gb2312"); System.out.println(URLEncoder.encode(newStr)); } catch (UnsupportedEncodingException e) { // TODO Auto-generated catch block e.printStackTrace(); }
輸出：
%E4%B8%AD%E6%96%87%E5%AD%97%E7%AC%A6
%E6%B6%93%EF%BF%BD%EF%BF%BD%EF%BF%BD%E7%80%9B%EF%BF%BD%E7%BB%97%EF%BF%BD
UTF-8的才是正確的。
URLEncoder.encode(String s) 過時了，使用下面的方法：
String oldStr = new String("中文字元"); try { System.out.println(URLEncoder.encode(oldStr, "utf-8")); System.out.println(URLEncoder.encode(oldStr, "gb2312")); } catch (UnsupportedEncodingException e) { // TODO Auto-generated catch block e.printStackTrace(); }
輸出：
%E4%B8%AD%E6%96%87%E5%AD%97%E7%AC%A6
%D6%D0%CE%C4%D7%D6%B7%FB
檢視預設編碼：
[java] view pl
System.out.println(Charset.defaultCharset()); //檢視預設編碼
問題又來了，兩次輸出的 GB2312 編碼的不一樣！一次那麼長，一次卻很短！
檢視的實現原始碼吧！
import java.io.CharArrayWriter;
import java.io.UnsupportedEncodingException;
import java.nio.charset.Charset;
import java.nio.charset.IllegalCharsetNameException;
import java.nio.charset.UnsupportedCharsetException;
import java.security.AccessController;
import java.util.BitSet;
import sun.security.action.GetPropertyAction;
public class URLEncoder
{
static BitSet dontNeedEncoding;
static final int caseDiff = 32;
static String dfltEncName = null;
@Deprecated
public static String encode(String paramString)
{
String str = null;
try
{
str = encode(paramString, dfltEncName);
}
catch (UnsupportedEncodingException localUnsupportedEncodingException)
{
}
return str;
}
public static String encode(String paramString1, String paramString2)
throws UnsupportedEncodingException
{
int i = 0;
StringBuffer localStringBuffer = new StringBuffer(paramString1.length());
CharArrayWriter localCharArrayWriter = new CharArrayWriter();
if (paramString2 == null)
throw new NullPointerException("charsetName");
Charset localCharset;
try
{
localCharset = Charset.forName(paramString2);
}
catch (IllegalCharsetNameException localIllegalCharsetNameException)
{
throw new UnsupportedEncodingException(paramString2);
}
catch (UnsupportedCharsetException localUnsupportedCharsetException)
{
throw new UnsupportedEncodingException(paramString2);
}
int j = 0;
while (j < paramString1.length())
{
int k = paramString1.charAt(j);
if (dontNeedEncoding.get(k))
{
if (k == 32)
{
k = 43;
i = 1;
}
localStringBuffer.append((char)k);
++j;
}
else
{
do
{
localCharArrayWriter.write(k);
if ((k < 55296) || (k > 56319) || (j + 1 >= paramString1.length()))
continue;
int l = paramString1.charAt(j + 1);
if ((l < 56320) || (l > 57343))
continue;
localCharArrayWriter.write(l);
++j;
}
while ((++j < paramString1.length()) && (!dontNeedEncoding.get(k = paramString1.charAt(j))));
localCharArrayWriter.flush();
String str = new String(localCharArrayWriter.toCharArray());
byte[] arrayOfByte = str.getBytes(localCharset);
for (int i1 = 0; i1 < arrayOfByte.length; ++i1)
{
localStringBuffer.append('%');
char c = Character.forDigit(arrayOfByte[i1] >> 4 & 0xF, 16);
if (Character.isLetter(c))
c = (char)(c - ' ');
localStringBuffer.append(c);
c = Character.forDigit(arrayOfByte[i1] & 0xF, 16);
if (Character.isLetter(c))
c = (char)(c - ' ');
localStringBuffer.append(c);
}
localCharArrayWriter.reset();
i = 1;
}
}
return (i != 0) ? localStringBuffer.toString() : paramString1;
}
static
{
dontNeedEncoding = new BitSet(256);
for (int i = 97; i <= 122; ++i)
dontNeedEncoding.set(i);
for (i = 65; i <= 90; ++i)
dontNeedEncoding.set(i);
for (i = 48; i <= 57; ++i)
dontNeedEncoding.set(i);
dontNeedEncoding.set(32);
dontNeedEncoding.set(45);
dontNeedEncoding.set(95);
dontNeedEncoding.set(46);
dontNeedEncoding.set(42);
dfltEncName = (String)AccessController.doPrivileged(new GetPropertyAction("file.encoding"));
}
package java.net;
import java.io.CharArrayWriter;
import java.io.UnsupportedEncodingException;
import java.nio.charset.Charset;
import java.nio.charset.IllegalCharsetNameException;
import java.nio.charset.UnsupportedCharsetException;
import java.security.AccessController;
import java.util.BitSet;
import sun.security.action.GetPropertyAction;
public class URLEncoder
{
static BitSet dontNeedEncoding;
static final int caseDiff = 32;
static String dfltEncName = null;
@Deprecated
public static String encode(String paramString)
{
String str = null;
try
{
str = encode(paramString, dfltEncName);
}
catch (UnsupportedEncodingException localUnsupportedEncodingException)
{
}
return str;
}
public static String encode(String paramString1, String paramString2)
throws UnsupportedEncodingException
{
int i = 0;
StringBuffer localStringBuffer = new StringBuffer(paramString1.length());
CharArrayWriter localCharArrayWriter = new CharArrayWriter();
if (paramString2 == null)
throw new NullPointerException("charsetName");
Charset localCharset;
try
{
localCharset = Charset.forName(paramString2);
}
catch (IllegalCharsetNameException localIllegalCharsetNameException)
{
throw new UnsupportedEncodingException(paramString2);
}
catch (UnsupportedCharsetException localUnsupportedCharsetException)
{
throw new UnsupportedEncodingException(paramString2);
}
int j = 0;
while (j < paramString1.length())
{
int k = paramString1.charAt(j);
if (dontNeedEncoding.get(k))
{
if (k == 32)
{
k = 43;
i = 1;
}
localStringBuffer.append((char)k);
++j;
}
else
{
do
{
localCharArrayWriter.write(k);
if ((k < 55296) || (k > 56319) || (j + 1 >= paramString1.length()))
continue;
int l = paramString1.charAt(j + 1);
if ((l < 56320) || (l > 57343))
continue;
localCharArrayWriter.write(l);
++j;
}
while ((++j < paramString1.length()) && (!dontNeedEncoding.get(k = paramString1.charAt(j))));
localCharArrayWriter.flush();
String str = new String(localCharArrayWriter.toCharArray());
byte[] arrayOfByte = str.getBytes(localCharset);
for (int i1 = 0; i1 < arrayOfByte.length; ++i1)
{
localStringBuffer.append('%');
char c = Character.forDigit(arrayOfByte[i1] >> 4 & 0xF, 16);
if (Character.isLetter(c))
c = (char)(c - ' ');
localStringBuffer.append(c);
c = Character.forDigit(arrayOfByte[i1] & 0xF, 16);
if (Character.isLetter(c))
c = (char)(c - ' ');
localStringBuffer.append(c);
}
localCharArrayWriter.reset();
i = 1;
}
}
return (i != 0) ? localStringBuffer.toString() : paramString1;
}
static
{
dontNeedEncoding = new BitSet(256);
for (int i = 97; i <= 122; ++i)
dontNeedEncoding.set(i);
for (i = 65; i <= 90; ++i)
dontNeedEncoding.set(i);
for (i = 48; i <= 57; ++i)
dontNeedEncoding.set(i);
dontNeedEncoding.set(32);
dontNeedEncoding.set(45);
dontNeedEncoding.set(95);
dontNeedEncoding.set(46);
dontNeedEncoding.set(42);
dfltEncName = (String)AccessController.doPrivileged(new GetPropertyAction("file.encoding"));
}
} 通過檢視原始碼我們可以明白，傳入的第二個引數是輸出的編碼，而不是指將傳入的第一個引數轉換為什麼型別的編碼；
預設它應該是讀取的容器（如：Tomcat）的預設編碼；
我們可以通過執行以下程式碼檢視：
dfltEncName = (String)AccessController.doPrivileged(new GetPropertyAction("file.encoding"));
System.out.println(dfltEncName); 需要在專案中新增一個類：GetPropertyAction.java [java] view plain copy
- package sun.security.action;
- import java.security.PrivilegedAction;
- public class GetPropertyAction
- implements PrivilegedAction<String>
- {
- private String theProp;
- private String defaultVal;
- public GetPropertyAction(String paramString)
- {
- this.theProp = paramString;
- }
- public GetPropertyAction(String paramString1, String paramString2)
- {
- this.theProp = paramString1;
- this.defaultVal = paramString2;
- }
- public String run()
- {
- String str = System.getProperty(this.theProp);
- return (str == null) ? this.defaultVal : str;
- }
- }
如果不是，就將其轉換為“UTF-8”，使用：String newStr = new String(oldStr.getBytes(), "utf-8");
然後再編碼：URLEncoder.encode(newStr, "utf-8");
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