对 DB2 V9 中 XML 类型的编码处理

                
try{
	//step 1: read file to byte array
	File file = new File(filename);
	int size = (int)file.length();
	FileInputStream fis = new FileInputStream(file);
	byte[] buff = new byte[size];
	int readed = 0;
	while (readed < size)
		readed += fis.read(buff, readed, size-readed);
	
	String BOM=null;
	String Dec=null;
	String Enc=null;
	String Encoding = null;
	boolean hasdec = false;
	
	//step 2: get encoding from BOM if exist
	int dec_start = 0;
	int b0 = buff[0] & 0xFF;
	int b1 = buff[1] & 0xFF;
	int b2 = buff[2] & 0xFF;
	if (b0 == 0xFE && b1 == 0xFF){ 
		BOM = "UTF-16BE";
		Encoding = BOM;
		dec_start = 2;
	}
	else if (b0 == 0xFF && b1 == 0xFE){ 
		BOM = "UTF-16LE";
		Encoding = BOM;
		dec_start = 2;
	}
	else if (b0 == 0xEF && b1 == 0xBB && b2 == 0xBF){
		BOM = "UTF-8";
		Encoding = BOM;
		dec_start = 3;
	}
	
	//step 3: get encoding from xml decoration 
	int d0 = buff[dec_start] & 0xFF;
	int d1 = buff[dec_start+1] & 0xFF;
	int d2 = buff[dec_start+2] & 0xFF;
	int d3 = buff[dec_start+3] & 0xFF;
	if (d0 == 0x3C && d1 == 0x3F){ //ascii encoding of "<?"
		Dec = "ASCII";
		if (Encoding!=null && Encoding.compareTo("UTF-8")!=0)
			System.out.print("Conflict");
		if (Encoding == null)
			Encoding = Dec;
		hasdec = true;
	}
	else if (d0 == 0x3C && d1 == 0x00 && d2== 0x3F && 
	d3 == 0x00){ //UTF-16 Little Ending encoding of "<?"
		Dec = "UTF-16LE";
		if (Encoding!=null && Encoding.compareTo("UTF-16LE")!=0)
			System.out.print("Conflict");
		if (Encoding == null)
			Encoding = Dec;
		hasdec = true;
	}
	else if (d0 == 0x00 && d1 == 0x3C && d2== 0x00 && 
	d3 == 0x3F){ //UTF-16 Big Ending encoding of "<?"
		Dec = "UTF-16BE";
		if (Encoding!=null && Encoding.compareTo("UTF-16BE")!=0)
			System.out.print("Conflict");
		if (Encoding == null)
			Encoding = Dec;
		hasdec = true;
	}
	
	//step 4: get encoding from decoration encoding	        
	if (hasdec){
		int i = dec_start;
		while ((buff[i]&0xFF) != 0x3E && i<buff.length)
			i++;
		if (i==buff.length){
			System.out.print("bad file.");
			return "";
		}
		String decoration = new String(buff, dec_start, i-dec_start, Dec);
		int pos = decoration.indexOf("encoding");
		if (pos!=-1){
			while (pos<decoration.length() && decoration.charAt(pos)!
			='"' && decoration.charAt(pos)!='\'')
				pos++;
			if (pos == decoration.length()){
				System.out.print("bad file.");
				return "";
			}
			char quot = decoration.charAt(pos);
			int encstart = ++pos;
			while (pos<decoration.length() && decoration.charAt(pos)!=quot)
				pos++;
			if (pos == decoration.length()){
				System.out.print("bad file.");
				return "";
			}
			Enc = decoration.substring(encstart,pos);
			if (Encoding.compareTo(Enc)!=0 && Encoding.compareTo("ASCII")!=0){
				System.out.print("bad file.");
				return "";
			}
			Encoding = Enc;	
		}
		if (Encoding.compareTo("ASCII")==0)
			Encoding = "UTF-8";
	}
	
	System.out.println("Encoding:"+Encoding);
	return new String(buff, dec_start, buff.length-dec_start, Encoding);
}catch(Exception e){
	e.printStackTrace();
}

                
String url = "jdbc:db2://localhost:50000/testdb";
Connection con;
PreparedStatement stmt;
ResultSet rs;

try 
{                                                                        
	// Load the IBM DB2 Driver for JDBC and SQLJ
	Class.forName("com.ibm.db2.jcc.DB2Driver");                             

	// Create the connection using the IBM DB2 Driver for JDBC and SQLJ
	con = DriverManager.getConnection (url, 
                                "db2admin","db2admin");                                
	con.setAutoCommit(true);

	// Create the Statement
	stmt = con.prepareStatement("insert into T1 values(?)");

	//insert a xml data, readfile from a.xml with UTF-8 encoding
	String xml = readfile("c:/temp/a.xml");
	stmt.setString(1, xml);
	stmt.executeUpdate();

	//insert a xml data, readfile from b.xml with GBK encoding	
	stmt = con.prepareStatement("insert into T1 values(?)");
	xml = readfile("c:/temp/tmp/b.xml");
	stmt.setString(1, xml);
	stmt.executeUpdate();
	
	// Close the Statement
	stmt.close();
	con.close();                                                             
}
catch (Exception e){
	e.printStackTrace();
}
      

                
<?xml version="1.0" encoding="UTF-8"?>
<node>
你好
</node>
      

                
<?xml version="1.0" encoding="GBK"?>
<node>
你好
</node>
      

                
File file = new File("c:/temp/tmp/c.xml");
int size = (int)file.length();
FileInputStream fis = new FileInputStream(file);
byte[] buff = new byte[size];
int readed = 0;
while (readed < size)
	readed += fis.read(buff, readed, size-readed);
stmt.setBytes(1, buff);
stmt.executeUpdate();
      

                
<?xml version="1.0" encoding="GBK"?>
<node>
你好
</node>
      

                
<?xml version="1.0" encoding="GBK"?>
<node>
浣犲ソ
</node>
      

                
<node>
你好
</node>
      

                    
<?xml version="1.0" encoding="GBK"?>
<node>
你好
</node>